[From the U.S. Government Printing Office, www.gpo.gov]



                             NOAA STATUS AND TRENDS
                                         Mussel Watch Project
                                                  Technical Report
                                                             Year IX


                                                     The Geochernical and
                                                     Environmental Research Group
                                                     Texas A&M Research Foundation






                                                                                                       Subjii@ 1b.'

                                                                                                U.S. Department ofCommerce,
                                                                                                onal
                                                                                          I! Nat , Oceanic& Atmospheric Adm.
                                                                                                 'Oce'anAssessment,l)iViston
                                                                                               6DOI Executive Blvd. Am. 323
                                                                                                                d 20852
                                                                                                ','@Rockville, Marylari'



                                                            a




                        100* w               95* W                90* w                85* w                80* w
                                                                                                             35' N









                                Texas                          Missi;sippi    Alabama

                                                        Louisla                              Florida             30* N







                   QH
                   541.5
                   .C65
                   T44
                                                                                                                    25' N
          LII:IKLI














                   year 9                                                                                                   Ir
                    Sept; .                                                                                         24* N
                   1994)

                                                       Se-p@tembe@r 9@@






                   NOAA NATIONAL
                   STATUS AND TRENDS

                   Mussel Watch Project

                   Year 9 Technical Report



                                                            property of CSC Library
                   Prepared by

                   The Geochemical and Environmental Research
                   Group (GERG)
                   Texas A&M University
                   833 Graham Road
                   College Station, Texas 77845



                   Submitted to

                   U.S. Department of Commerce
                   National Oceanic & Atmospheric Administration
                   1305 East-West Hwy.
                   Silver Spring, MD 209 10
                                                                  U,S, DFPARTMFNT     nr COMMERCE NOAA
                                                                                         JIVIER
                                                                                           VEN@IE
                   September 1994
                                                                                  b C  -`@j 4 0 5 - 2 4 13





















                                                                TABLE OF CONTENTS



                         Introduction         ...........................................................................................             1

                         Reprint 1: Accumulation and Depuration of Organic
                              Contaminants by the American Oyster (Crassostrea
                              virginica)     ............................................................................................          10

                         Reprint 2: Toxicological Significance of Non-, Mono- and Di-
                              ortho-Substituted Polychlorinated Biphenyls in Oysters
                              fTom Galveston and Tampa Bays                        ........................................................        35

                         Reprint 3: Distribution and Sources of Organic Contaminants
                              in Tidal River Sediments of the Washington, DC Area                                ..........................        43

                         Reprint 4: Distribution and Sources of Trace Metals to Tidal
                              River Sediments of Washington, DC                       ....................................................         89









                 NOAX 8 NATIONAL STATUS AND TRENDS (NS&T) MUSSEL WATCH
                                     PROGRAM - GULF OF MEXICO


                       The purpose of the NOAA National Status and Trends (NS&T)
                Mussel Watch Project is to determine the long-term temporal and spatial
                trends of selected environmental contaminant concentrations in bays
                and estuaries. The key questions in this regard are:

                       (1) What is the current condition of the nation's coastal zone?
                       (2) Are these conditions getting better or worse?

                       This report represents the Year 9 Technical Report from this multi-
                year project. These questions have been addressed in detail as evidenced
                by the scientific papers and reports that have resulted from the
                Geochemical and Environmental Research Group's (GERG)
                interpretations of the Gulf Coast data (Table 1). Publications not
                included in GERG's previous Technical Reports are contained in this
                technical report.

                       This report is an update on the current condition of the Gulf of
                Mexico coastal zone, based on results from Years 1 through 9 of the
                NOAA NS&T Mussel Watch Project. Following is a brief sampling survey
                of these years:

                        Year 1 -   49 sites (147 stations) of the original 51 sites were
                                   successfully sampled. Sediments and oysters were
                                   analyzed at triplicate stations from all sites.
                        Year 2 -   48 sites (144 stations) of the original 51 sites were
                                   successfully sampled. Sediments and oysters were
                                   analyzed at triplicate stations from all sites.
                        Year 3 -   Twenty (20) sites were added to the original list of 51
                                   sites for a total of 71 sites. Sixty-four (64) sites (192
                                   stations) of the 71 sites were sampled (only 19 of the
                                   new sites were sampled). Oysters were analyzed at
                                   triplicate stations from all sites. Sediments were
                                   analyzed at only the new sites (three stations analyzed
                                   per site).
                        Year 4 -   Seven (7) new sites were added (only six of the new sites
                                   were successfully sampled). Sixty-seven (67) sites (201
                                   stations) of the 78 total sites were sampled. Oysters
                                   were analyzed at triplicate stations from all sites.
                                   Sediments were analyzed at only the new sites (three
                                   stations analyzed per site).
                        Year 5 -   Three (3) new sites were added to the sampling project
                                   (only two of these sites were successfully sampled;
                                   79:MBDR and 80:PBSP). Sixty-eight (68) sites (204
                                   stations) of the 80 total sites were sampled. Oysters
                                   were analyzed at triplicate stations from all sites.



                                                      1








                                   Sediments were analyzed at only the new sites (three
                                   stations analyzed per site).
                        Year 6 -   Two (2) new sites were added to the sampling project
                                   (81:BHKF in Bahia Honda Key, FL and 63:LPGO in
                                   Lake Pontchartrain, LA). Sixty-four (64) sites (192
                                   stations) were sampled. Oysters were analyzed at
                                   triplicate stations from all sites. Sediments were
                                   analyzed at only the new sites (three stations analyzed
                                   per site).
                        Year 7 - Five new sites were established including three new
                                   sites in Puerto Rico (Sites 86 to 88) and two new sites
                                   in Choctawhatchee Bay (Sites 84 and 85). Sixty-seven
                                   (67) sites were analyzed. Only one oyster analysis was
                                   conducted at each of the old sites on a composite from
                                   the three stations. Sediments were analyzed at the five
                                   new sites and one site in Florida (PBPH) (three stations
                                   analyzed per site).
                        Year 8 -   Sixty-eight (68) existing sites were sampled. Only one
                                   oyster analysis was conducted at each of the existing
                                   sites on a composite from the three stations.
                                   Sediments were not collected at any sites.
                        Year 9 -   A total of 55 sites were visited and 51 of them were
                                   successfully sampled. Four of the originally scheduled
                                   sites were devoid of any live oysters. Two new sites
                                   were established in Florida Bay (Flamingo Bay, FBFO;
                                   and Joe Bay, FBJB). At these Is these new sites both
                                   triplicate sediments and oysters were sampled. No
                                   other sediment samples were taken this year. Only one
                                   oyster analysis was conducted at each of the existing
                                   sites on a composite from the three stations.

                Details of the sample collection and location of field sampling sites are
                contained in a separate report titled "Field Sampling and Logistics in
                Year 9".

                       The oyster and sediment samples were analyzed for contaminant
                concentrations [trace metals, polynuclear aromatic hydrocarbons (PAH),
                pesticides and polychlorinated biphenyls (PCBs)], and other parameters
                that aid in the interpretation of contaminant distributions (grain size,
                oyster size, lipid content, etc.). The analytical procedures used and the
                QA/QC Project Plan are detailed in a separate report titled "Analytical
                Methods". The data that were produced from the sample analyses for
                Year 9 are found in a separate report titled "Analytical Data".

                       A complete and comprehensive interpretation of the data from the
                National Status and Trends Project for oyster data coupled with the
                sediment data is an on-going process. We have begun and are
                continuing that process as evidenced by this report and the scientific
                manuscripts that we have published or submitted for publication (Table
                1). As part of the data interpretation and dissemination, over 40


                                                      2









               presentations of the NOAA NS&T Gulf Coast Mussel Watch Project were
               given at national and international meetings. With eight years of data,
               the question of temporal trends of contaminant concentrations has been
               addressed. A general conclusion found for most contaminants measured
               is that the concentrations have remained relatively constant over the
               nine year sampling period. This general trend, however, is not observed
               at all sites. Some sites show significant changes (both increases and
               decreases) among the years. Continued sampling is addressing the
               frequency and rates of these changes.

                      Exceptions to this general txend are found for DDTs and TBT.
               When historical data for DDT in bivalves is compared to current NS&T
               data, a decrease in concentration is apparent. Also based on TBT data
               collected as part of the NOAA NS&T Mussel Watch Project, a decline in
               TBT concentration in oysters is apparent. Both declines may be in
               response to regulatory actions.

                      During Year 3 of this project, 20 new sites were added. These sites
               were chosen to be closer to urban areas, and therefore, to the sources of
               contaminant inputs. These new sites were not, however, located near
               any known point sources of contaminant input. These sites were added
               to better represent the current status of contaminant concentrations in
               the Gulf of Mexico. Over the subsequent years of the project (Years 4
               through 9) additional sites have been added to increase the
               representative coverage of the Gulf of Mexico and U.S. Caribbean
               territories.

                      While sampling sites for this project were specifically chosen to
               avoid known point sources of contamination, the detection of coprostanol
               in sediment from all sites indicates that the products of man's activities
               have reached all of the sites sampled. However, when compared to
               known point sources of contamination, all of the contaminant
               concentrations reported are, in most cases, many orders of magnitude
               lower than obviously contaminated areas. The lower concentrations in
               Gulf of Mexico samples most likely reflect the fact that the sites are
               further removed from point sources of inputs, a condition which is
               harder to achieve in East and West Coast estuaries. In fact, new sites
               added in Years 3 through 7 are closer to urban areas and generally had
               higher contaminant concentrations. An important conclusion derived
               from the extensive NS&T data set is that contamination levels in Gulf
               Coast near shore areas remain the same or are getting better, and most
               areas removed from point sources are not severely contaminated.

                      This document represents one of three report products as part of
               Year 9 of the NS&T Gulf of Mexico projects. The other two reports are
               entitled:

                         Analytical Data, Year 9
                         Field Sampling and Logistics, Year 9



                                                    3










                  Table 1. GERG/NOAA NS&T PUBLICATIONS                                       Included in
                                                                                            Year Report

                  Wade, T.L., B. Garcia-Romero and J.M. Brooks (1988)
                          Tributyltin contamination of bivalves from U.S. coastal
                          estuaries. Environmental Science and Technology, 22:
                          1488-1493.                                                               IV

                  Wade, T.L., E.L. Atlas, J.M. Brooks, M.C. Kennicutt H, R.G. Fox,
                          J. Sericano, B. Garcia-Romero and D. DeFreitas (1988)
                          NOAA Gulf of Mexico Status and Trends Program:
                          Trace organic contaminant distribution in sediments
                          and oysters. Estuaries, 11: 171-179.                                     IV

                  Wade, T.L., B. Garcia-Romero and J.M. Brooks (1988)
                          Tributyltin analyses in association with NOAA's
                          National Status and Trends Mussel Watch Program. In:
                          OCEANS '88 Conference Proceedings, Baltimore, MD, 31
                          Oct. - 2 Nov. 1988, pp. 1198-1201.                                       IV

                  Wade, T.L., M.C. Kennicutt, II and J.M. Brooks (1989) Gulf of
                          Mexico hydrocarbon seep communities: M: Aromatic
                          hydrocarbon burdens of organisms from oil seep
                          ecosystems. Marine Environmental Research, 27: 19-30.                    IV

                  Wade,   T.L. and J.L. Sericano (1989) Trends in organic
                          contaminant distributions in oysters from the Gulf of
                          Mexico. In: Proceedings, Oceans '89 Conference, Seattle,
                          WA, pp. 585-589.                                                         IV

                  Wade, T.L. and B. Garcia-Romero (1989) Status and trends of
                          tributyltin cont=dnation of oysters and sediments from
                          the Gulf of Mexico. In: Proceedings, Oceans '89
                          Conference, Seattle, WA, pp. 550-553.                                    IV

                  Wade, T.L. and C.S. Giam (1989) Organic contaminants in the
                          Gulf of Mexico. In: Proceedings, 22nd Waterfor Texas
                          Conference, Oct. 19-21, 1988, South Shore Harbour Resort
                          and Conference Center, League City, TX (R. Jensen and C.
                          Dunagan, Eds.), pp. 25-30.                                                 V

                  Craig,  A., E.N. Powell, R.R. Fay and J.M. Brooks (1989)
                          Distribution of Perkinsus marinus in Gulf coast oyster
                          populations. Estuaries, 12: 82-91.                                       IV

                  Presley, B.J., R.J. Taylor and P.N. Boothe (1990) Trace metals
                          in Gulf of Mexico oysters. The Science of the Total
                          Environment, 97/98: 551-553.                                             IV








                                                             4










                   Sericano, J.L., E.L. Atlas, T.L. Wade and J.M. Brooks (1990)
                          NOAA's Status and Trends Mussel Watch Program:
                          Chlorinated pesticides and PCB's in oysters
                          (Crassostrea virginica) and sediments from the Gulf of
                          Mexico, 1986-1987. Marine Environmental Research, 29:
                          161-203.                                                                  IV

                   Wade, T.L., B. Garcia-Romero and J.M. Brooks (1990) Butyltins
                          in sediments and bivalves from U.S. coastal areas.
                          Chemosphere, 20: 647-662.                                                 IV

                   Brooks, J.M., M.C. Kennicutt II, T.L. Wade, A.D. Hart, G.J.
                          Denoux and T.J. McDonald (1990) Hydrocarbon
                          distributions around a shallow water multiwell
                          platform. Environmental Science and Technology, 24:
                          1079-1085.                                                                IV

                   Sericano, J.L., T.L. Wade, E.L. Atlas and J.M. Brooks (1990)
                          Historical perspective on the environmental
                          bioavailability of DDT and its derivatives to Gulf of
                          Mexico oysters. Environmental Science and Technology,
                          24: 1541-1548.                                                            IV

                   Wade, T.L., J.L. Sericano, B. Garcia-Romero, J.M. Brooks and
                          B.J. Presley (1990) Gulf coast NOAA National Status &
                          Trends Mussel Watch: the first four years. In: MTS'90
                          Conference Proceedings, Washington, D.C., 26-28
                          September 1990, pp. 274-280.                                           IV, V

                   Brooks, J.M., T.L. Wade, B.J. Presley, J.L. Sericano, T.J.
                          McDonald, T.J. Jackson, D.L. Wilkinson and T.F. Davis
                          (1991) Toxic contamination of aquatic organisms in
                          Galveston      Bay. In: Proceedings Galveston Bay
                          Characterization Workshop, February 21-23, pp. 65-67.                     VI

                   Wade, T.L. J.M. Brooks, J.L. Sericano, T.J. McDonald, B. Garcia-
                          Romero, R.R. Fay, and D.L. Wilkinson (1991) Trace
                          organic contamination in Galveston Bay: Results from
                          the NOAA National Status and Trends Mussel Watch
                          Program In: Proceedings Galveston Bay Characterization
                          Workshop, February 21-23, pp. 68-70.                                      VI

                   Presley, B.J., R.J. Taylor and P.N. Boothe (1991) Trace metals
                          in Galveston Bay oysters. In: Proceedings Galveston Bay
                          Characterization Workshop, February 21-23, pp. 71-73.                     VI

                   Sericano, J.L., T.L. Wade and J.M. Brooks (199 1) Transplanted
                          oysters as sentinel organisms in monitoring studies. In:
                          Proceedings Galveston Bay Characterization Workshop,
                          February 21-23, pp. 74-75.                                                VI





                                                             5









                   McDonald, S.J., J.M. Brooks, D. Wilkinson, T.L. Wade and T.J.
                           McDonald (1991) The effects of the Apex Barge oil spill
                           on the fish of Galveston Bay. In: Proceedings Galveston
                           Bay Characterization Workshop, February 21-23, pp. 85-
                           86.                                                                         VI

                   Wade, T.L., J.M. Brooks, M.C. Kennicutt H, T.J. McDonald, G.J.
                           Denoux and T.J. Jackson (1991) Oysters as biomonitors
                           of oil in the ocean. In: Proceedings 23rd Annual Offshore
                           Technology Conference, No. 6529, Houston, TX, May 6-
                           9,, pp. 275-280.                                                             V

                   Brooks, J.M., M.A. Champ, T.L. Wade, and S.J. McDonald
                           (1991) GEARS: Response strategy for oil and
                           hazardous spills. Sea Technology, April 1991, pp. 25-32.                     V

                   Sericano, J.L., T. L. Wade and J.M. Brooks (1991) Chlorinated
                           hydrocarbons in Gulf of Mexico oysters: Overview of
                           the first four years of the NOAA's National Status and
                           Trends Mussel Watch Program (1986-1989). In: Water
                           Pollution: Modelling, Measuring and Prediction. Wrobel,
                           L.C. and Brebbia, C.A. (Eds.), Computational Mechanics
                           Publications, Southampton, and Elsevier Applied Science,
                           London, pp. 665-681.                                                    V, VI

                   Wade, T.L., B. Garcia-Romero and J.M. Brooks (1991)
                           Bioavailability of butyltins. In: Organic Geochemistry -
                           Advances and Applications in the Natural Environment.
                           Manning, D.A.C. (Ed.), Manchester University Press,
                           Manchester, pp. 571-573.                                                     V

                   Wilson, E.A., E.N. Powell, M.A. Craig, T.L. Wade and J.M.
                           Brooks (1991) The distribution of Perkinsus marinus in
                           Gulf coast oysters: its relationship with temperature,
                           reproduction and pollutant body burden. Int. Reuve der
                           Gesantan Hydrobioligie, 75: 533-550.                                        IV

                   Sericano, J.L., A.M. El-Husseini and T.L. Wade (1991) Isolation
                           of planar polychlorinated biphenyls by carbon column
                           chromatography. Chemosphere, 23(7): 915-924.                            V, V1

                   Wade, T.L., B. Garcia-Romero and J.M. Brooks (1991) Oysters
                           as biomonitors of butyltins in the Gulf of Mexico.
                           Marine Environmental Research, 32: 233-241.                             IV, V

                   Wilson, E.A., E.N. Powell, T.L. Wade, R.J. Taylor, B.J. Presley
                           and J.M. Brooks (1991) Spatial and temporal
                           distributions of contaminant body burden and disease
                           in Gulf of Mexico oyster populations: The role of local
                           and large-scale climatic controls. Helgolander
                           Meeresunters, 46: 201-235.                                              V, V1





                                                               6









                  Powell, W.N., J.D. Gauthier, E.A. Wilson, A. Nelson, R.R. Fay
                          and J.M. Brooks (1992) Oyster disease and climate
                          change. Are yearly changes in Perkinsus marinus
                          parasitism in oysters (Crassostrea virginica) controlled
                          by climatic cycles in the Gulf of Mexico? PSZNI: Marine
                          Ecology, 13: 243-270.                                                     IV

                  Hofmann, E.E., E.N. Powell, J.M. Klinck E.A. Wilson (1992)
                          Modeling oyster populations Ill. critical feeding
                          periods, growth and reproduction. J.             Shellfish
                          Research, 2: 399-416.                                                       V

                  Sericano, J.L., T.L. Wade, A.M. El-Husseini and J.M. Brooks
                          (1992) Environmental significance of the uptake and
                          depuration of planar PCB congeners by the American
                          oyster (Crassostrea virginica). Marine Pollution Bulletin,
                          24: 537-543.                                                              VI

                  Wade, T.L., E.N. Powell, T.J. Jackson and J.M. Brooks (1992)
                          Processes controlling temporal trends in Gulf of Mexico
                          Oyster health and contaminant concentrations. In:
                          Proceedings MTS '92, Marine Technology Society, Oct. 19 -
                          2 1, Washington, D.C. pp. 223-229.                                        VI

                  Tripp, B.W., J.W. Farrington, E.D. Goldberg and J.L. Sericano
                          (1992) International mussel watch: the initial
                          implementation phase. Marine Pollution Bulletin, 24:
                          371-373.                                                                  VI

                  Sericano, J.L., T.L. Wade and J.M. Brooks (1993) The
                          usefulness of transplanted oysters in biomonitoring
                          studies. In: Proceedings of The Coastal Society Twetfth
                          International Conference, Oct. 21-24, 1990, San Antonio,
                          TX, pp. 417-429.                                                      V, VH

                  Wade, T.L., J.L. Sericano, J.M. Brooks and B.J. Presley (1993)
                          Overview of the first four years of the NOAA National
                          Status and Trends Mussel Watch Program.                 In:
                          Proceedings of The Coastal Society Twelfth International
                          Conference, Oct. 21-24, 1990, San Antonio, TX, pp. 323-
                          334.                                                                  V, VH

                  Sericano, J.L., T.L. Wade, E.N. Powell and J.M. Brooks (1993)
                          Concurrent chemical and histological analyses: Are
                          they compatible? Chemistry and Ecology, 8: 41-47.                     V, VI

                  Sericano, J.L., T.L. Wade, J.M. Brooks, E.L. Atlas, R.R. Fay and
                          D.L. Wilkinson (1993) National Status and Trends
                          Mussel Watch Program: chlordane-related compounds
                          in Gulf of Mexico oysters: 1986-1990. Environmental
                          Pollution, 82: 23-32.                                                 V, VI





                                                             7









                   Wade, T.L., T.J. Jackson, J.M. Brooks, J.L. Sericano, B. Garcia-
                          Romero and D.L. Wilkinson (1993) Trace organic
                          contamination in Galveston Bay oysters: results from
                          the NOAA National Status and Trends Mussel Watch
                          Program. In: Proceedings, The Second State of the Bay
                          Symposium, Galveston, TX, February 4-6, pp. 109-111.                      Vil

                   Presley, B.J. and K.T. Jiann (1993) Indicators of trace metal
                          pollution in Galveston Bay. In: Proceedings, The Second
                          State of the Bay Symposium, Galveston, TX, February 4-6,
                          pp. 127-13 1.                                                             VII

                   Wade, T.L., T.J. Jackson, T.J. McDonald, D.L. Wilkinson, and
                          J.M. Brooks (1993) Oysters as biomonitors of the APEX
                          barge oil spill. In: Proceedings, 1993 International Oil
                          Spill Conference, Tampa, FL, March 29-April 1, pp. 127-
                          131.                                                                      V111

                   Palmer, S.J., B.J. Presley, R.J. Taylor and E.N. Powell (1993)
                          Field studies using the oyster Crassostrea virginica to
                          determine mercury accumulation and depuration rates.
                          Bulletin Environmental Contamination Toxicology, 51:
                          464 470.                                                                  VII

                   Morse, J.W., B.J. Presley and R.J. Taylor (1993) Trace metal
                          chemistry of Galveston Bay: water, sediment and biota.
                          Marine Environmental Research, 36: 1-37.                                  VII

                   Sericano, J.L. (1993) The American oyster (Crassostrea
                          virginica) as a bioindicator of trace organic
                          contamination.     Ph.D. Dissertation, Department of
                          Oceanography, Texas A&M University, 242 p.                                V11

                   Palmer, S.J. and B.J. Presley (1993) Mercury bioaccumulation
                          by shrimp (Penaeus aztecus) transplanted to Lavaca
                          Bay, Texas. Marine Pollution Bulletin, 26(10): 564-566.                   VII

                   Garcia-Romero, B., T.L. Wade, G.G. Salata, and J.M. Brooks
                          (1993) Butyltin concentrations in oysters from the Gulf
                          of Mexico during 1989-1991. Environmental Pollution,
                          81: 103-111.                                                           vi, VII

                   Ellis, M.S., K.-S. Choi, T.L. Wade, E.N. Powell, T.J. Jackson and
                          D.H. Lewis (1993) Sources of local variation in
                          polynuclear aromatic hydrocarbon and pesticide body
                          burden in oysters (Crassostrea virginica) from Galveston
                          Bay, Texas. Comparative Biochemistry and Physiology,
                          106C: 689-698.                                                        VI, VEII

                   Kennicutt, M.C. 11, T.L. Wade, B.J. Presley, A.G. Requejo, J.M.
                          Prooks and G.J. Denoux (1993) Sediment contaminants
                          in Casco Bay, Maine: inventories, sources and potential
                          for biological effects. Environmental Science and
                          Technology, 28(l): 1-15.                                                  VIII


                                                              8










                  Jackson, T.J., T.L. Wade, T.J. McDonald, D.L. Wilkinson and J.M.
                         Brooks (1994) Polynuclear aromatic hydrocarbon
                         contaminants in oysters from the Gulf of Mexico (1986-
                         1990). Environmental Pollution, 83: 291-298.                   V1, VIE[, VM

                  Sericano, J.L., T.L. Wade, B. Garcia-Romero and J.M. Brooks
                         (1994) Environmental accumulation and depuration of
                         tributyltin by the American Oyster, Crassostrea
                         Wrginica. Marine Environmental Research (in press).                      IV

                  Hofmann, E.E., J.M. Klinck, E.N. Powell, S. Boyles, M. Ellis
                         (1994) Modeling oyster populations H. Adult size and
                         reproductive effort. Journal of Shelyish Research, 13(l):
                         165-182.                                                            V, Vul

                  McDonald, S.J., M.C. Kennicutt I[[, J.L. Sericano, T.L. Wade, H.
                         Liu, and S.H. Safe (1994) Correlation between bioassay-
                         derived P450 1A 1 -Induction activity and chemical
                         analysis of clam (Laternuld elliptica) extracts from
                         McMurdo Sound, Antarctica. Chemosphere, 28(12):
                         2237-2248.                                                              VIII

                  Sericano, J.L., T.L. Wade and J.M. Brooks (1994) Accumulation
                         and depuration of organic compounds by the American
                         oyster (Cassostrea virginica). Science of the Total
                         Environment (in press).                                                  IX

                  Sericano, J.L., S.H. Safe, T.L. Wade, and J.M. Brooks (1994)
                         Toxicological significance of non-, mono-, and di-ortho
                         substituted polychlorinated biphenyls in oysters from
                         Galveston and Tampa Bays. Environmental Toxicology
                         and Chemistry, 13(11): x-xx (in press).                                  ix

                  Velinsky, D.J., T.L. Wade, C.E. Schlekat, B.L. McGee, and B.J.
                         Presley (1994) Tidal river sediments in the Washington,
                         D.C. area. I. Distribution and sources of trace metals.
                         Estuaries, 17: 305-320.                                                  IX

                  Wade, T.L., D.J. Velinsky, E. Reinharz, and C.E. Schlekat (1994)
                         Tidal river sediments in the Washington, D.C. area. H.
                         Distribution and sources of organic contaminants.
                         Estuaries, 17: 321-333.                                                  IX













                                                            9














                          Reprint I


         Accumulation and Depuration. of Organic
           Contaminants by the American Oyster
                   (Crassostrea virginica)

         Jose L. Sericano, Terry L. Wade and James M.
                            Brooks

















                              10







                                                                        Sericano et al. - I



                ACCUMULATION AND DEPURATION OF ORGANIC CONTAMINANTS

                     BY THE AMERICAN OYSTER (CRASSOSTREA VIRGINICA)




                       JOSE L. SERICANO, TERRY L. WADE and JAMES M. BROOKS

                               Geochemical and Environmental Research Group

                                 College of Geosciences and Maritime Studies

                                         Texas A&M University

                            833 Graham Rd., College Station, Texas 77845, U.S.A.







                                                                                                Sericano et al. - 2



                   ABSTRACT


                         Oysters and other bivalves are widely used to assess the levels of environmental

                   contamination; however, very little actual field calibration of bivalves has been done. The

                   purpose of this research, therefore, has been to evaluate the uptake and depuration of

                   selected PCBs and PAHs in transplanted American oysters, Crassostrea virginica, under

                   field conditions in Galveston Bay, Texas. Transplanted oyster were found to bioaccumulate

                   contaminants and reach concentrations nearly equal to those of indigenous oysters for PAI-Is

                   and low molecular weight PCBs within 30 to 48 days. In contrast, high molecular weight

                   PCBs did not reach equivalent concentrations. When returned to a clean environment,

                   oysters significantly depurated PAHs and low molecular weight PCBs. There were,

                   however, differences in depuration rates when newly contaminated oysters were compared

                   to chronically contaminated oysters. Oysters are useful tools in biomonitoring studies but

                   have their limitations. Transplant studies help to establish these limitations on the use of

                   oysters as sentinel organisms to avoid misleading interpretation of the oyster contaminant

                   concentrations.
































                                                                12







                                                                                                 Sericano et at. - 3



                    RiTRODUCTION


                         Contamination of the coastal marine environment by a number of organic compounds

                    of synthetic or natural origin has received increasing attention over the last several years.

                    Biomonitoring of these compounds in the aquatic environment has been well established and

                    bivalves are generally preferred for this purpose. The rationale for the "Mussel Watch"

                    approach using different bivalves, e.g. mussel, oysters and/or clams, has been summarized

                    by different authors (Goldberg et al., 1978; Farrington et al., 1980; Phillips, 1980;

                    Risebrough et al., 1983) and its concept has been applied to several monitoring programs

                    during the last decade (Farrington et al., 1983; Martin, 1985; Tavares et al., 1988; Wade et

                    al., 1988; Sericano et al., 1990; Tripp et al., 1992).


                         Several studies have examined the dynamics of the uptake and depuration of trace

                    organic contaminants; however, the information found in the literature is confusing. As an

                    example, Table I lists a number of studies published over the last two decades that report

                    the depuration of different hydrocarbon mixtures by bivalves. The contradicting results of

                    these studies, most of them carried out in laboratories, are obvious. Bivalves need to be

                    "calibrated" under real environmental conditions to be valuable as bioindicators of organic

                    contamination. Uptake and depuration rates of organic contaminants, compound selectivity,

                    interaction between different xenobiotics, seasonal effects on the body concentrations of

                    xenobiotics and differences between species need to be known to take full advantage of the

                    "Mussel Watch" concept.


                         The present study was designed to examine the rate of uptake and depuration of

                    selected trace organic contaminants, e.g. polynuclear aromatic hydrocarbons (PAHs) and

                    polychlorinated biphenyls (PCBs), in oysters (Crassostrea virginica) during transplantation
                    experiments in two locations in Galveston Bay, Texas. Uptake and depuration rates of

                    selected organic compounds by transplanted oysters were determined. Clearance rates




                                                                   13







                                                                                               Sericano et al. - 4


                   determined for newly contaminated oysters are compared to depuration rates found in

                   chronically polluted oysters.


                   MATERIALS AND METHODS


                   Experimental design


                        Approximately 250 oysters of similar dimensions were collected from a relatively

                   uncontaminated area in Galveston Bay, Hanna Reef, and transplanted in 2400 cm net bags,

                   containing 25-30 individuals per bag, to a new location near the Houston Ship Channel in

                   the upper part of the Bay (Fig. 1). Composite samples of 20 transplanted and 15

                   indigenous oysters were collected at 0, 3, 7, 17, 30, and 48 days during the first phase of

                   the transplantation experiment. The remaining Hanna Reef oysters were then back-

                   transplanted to their original location in Galveston Bay. At the same time, approximately

                   150 indigenous oysters from the Ship Channel site were also transplanted to the Hanna Reef

                   area. Composite samples of 20 oysters from each population were collected at 0, 3, 6, 18,

                   30, and 50 days after transplantation.


                   Analytical method


                        The analytical procedures used during this study are modifications of previously

                   reported methods (MacLeod et al., 1985) and are fully described elsewhere (Wade et al.

                   1988; Sericano et al, 1990). Briefly, approximately 10- 15 g of wet tissue are dried with

                   Na2SO4 and macerated with methylene chloride with a Tissurnizer for 3 minutes after the

                   addition of internal standards. This extraction is repeated twice more with new additions of

                   methylene chloride. Combined extracts are concentrated to a final volume of 2 mL in

                   hexane for silica gel-alumina chromatography clean-up. Silica gel is activated prior to use

                   by heating at 170'C for 12 hr and then partially deactivated with 5% water. Alumina is

                   activated at 400*C for 4 hr and then partially deactivated with I% water. The column is

                   slurry-packed in methylene chloride with 10 g of alumina over 20 g of silica gel. Sample



                                                                14







                                                                                               Sericano et al. - 5


                    extracts are eluted from the column using 50 mL of pentane (f 1=aliphatic hydrocarbons) and

                    then with 200 mL of a pentane:methylene chloride (50:50) mixture (f2=chlorinated

                    hydrocarbons, including PCBs, and PAHs). The f2-fraction is further purified by high

                    performance liquid chromatography (Krahn et al., 1988).


                         The PAHs in f2-fraction were separated and quantitated by GC/MS using an HP-

                    5880-GC interface with an HP5970-MSD. Sample extractss were injected in the splitless

                    mode on a 30 m x 0.25 mm (0.32 gm film thikness) DB-5 fused silica capillary column at
                    an initial temperature of 60'C. The oven temperature was programmed at 12'C min-] to

                    300*C and held at the final temperature for 6 min. The mass spectral data were acquired

                    using selected ions for each of the PAHs, The instuments were calibrated using a five-point

                    calibration curve and the calibration was checked by running continuing calibrations

                    standards with each set of samples with no more than 6 hr between calibrations checks.

                    Analyte concentrations were calculated using the mean relative response factors for each

                    analyte relative to the internal standards added before extraction.


                          Samples were analyzed for PCB congeners by fused-silica capillary column GC-ECD
                    (Ni63) using a Hewlett-Packard 5880A GC in the splitless mode. The DB-5 capillary

                    column (30 m x 0.25 mm; 0.25 gm film thikness) was temperature-programmed from
                    1000C to 1400C at 50C min-1, from 1400C to 250'C at 1.50C min-1, and from 2500C to
                    3000C at IO'C min'l with I min hold time at the beginning of the program and before each

                    program rate change. The final temperature was held for 5 min. Injector and detector

                    temperatures were set at 2750C and 325'C, respectively. These compounds were quantitated

                    against a set of authentic standards that were injected at four different concentrations to

                    calibrate the instrument and to compensate for non-linear response of the detector.









                                                                 15







                                                                                                       Sericano et al. - 6



                     Quality controllquality assurance (QAIQC)


                           Interim reference materials as well as spiked blanks, duplicate samples and spiked

                     samples were analyzed along with each sample set as part of the laboratory


                           QA/QC program. Evaluation of the analytical methods and possible sources of error

                     are a continuing and ongoing process in order to assure the realibility of the data.


                     RESULTS AND DISCUSSION


                           The concentrations of some of the organic contaminants increased dramatically during

                     the seven-week exposure period. Comparatively, concentrations of some individual PAHs

                     and PCBs in indigenous oysters during the first phase of this experiment were fairly

                     constant. The analyte concentrations in native oysters represent the time-integrated

                     c n n t a m 1 nant concentrations available to the oysters in solution, adsorbed onto particles and

                     incorporated with food.


                     Polynuclear Arornatic Hydrocarbons


                           Initial concentrations of total PAHs, ie. surn of 24 individual analytes (Sericano et al.,
                     1993), in transplanted oysters increased from 290 ng g-1 to a final value of 4360 ng g-1. By

                     the end of 48 days, transplanted oysters accumulated these PAHs to levels that were not

                     statistically differentiable from the concentrations measured in native individuals (Fig. 2).

                     Two- and three-ring PAHs were detected in low concentrations in both transplanted and

                     indigenous oysters while four- and five-ring compounds were detected in high

                     concentrations. The PAHs accumulated to the highest concentrations by transplanted

                     oysters were: pyrene >flu oran thene>chry sen e >ben zo (e) pyre ne>benzo(b)anthracen e.

                     Although in slightly different order, approximately the same PAHs were reported to be

                     preferentially accumulated by clams and mussels exposed to sediments contaminated with
                     relatively high PAH concentrations, i.e. pyrene >ben zo(e)pyrene>benzo(b)fluoranthene>



                                                                     16








                                                                                                       Sericano et al. - 7


                     benz(a)anthracene (Obana et al., 1983) and chrysene>benzo(b)fluoranthene>fluoranthene>

                     benzo(e)pyrene>benz(a)anthracene (Pruell et al., 1986), respectively.


                           Hanna Reef and Ship Channel oysters showed statistically significant depuration

                     (p<0.05) of four- and five-ring PAHs after relocation to the Hanna Reef area. Depurations

                     of these aromatic compounds by both groups of oysters were approximately exponential.

                     This is indicated in Fig. 3 where the concentration of selected PAHs plotted on a semi-log

                     plot approximate straight lines.


                           Kinetics parameters describing uptake and release of PAHs can be calculated assuming

                     the first-order equation


                                                    dCddt = ku Cw - kd Ct                                     (1)


                     where Ct is the PAH concentration in the transplanted oyster at time=t, Cw is the PAB

                     concentration in the seawater, and ku and kd are the uptake and depuration rate constant,

                     respectively. If the Cw at Hanna Reef is regarded as zero, i.e. Cw--O, which is considerably

                     reasonable because of the very low PAH concentrations measured in indigenous oysters,

                     then equation (1) reduces to


                                                         dCddt = -kd Ct                                       (2)


                     or, after integration,


                                                log Ct = Log Co-(kd/2.301) t                                  (3)


                     where CO is the PAH concentration in oysters at the time of their relocation to the Hanna

                     Reef area. Using this equation and the PAH concentrations corresponding to both oyster

                     populations during the depuration period, values of kd can be calculated.


                           Statistical analyses, at the a = 0.05 level, of the regression lines of the logarithm of the

                     concentrations versus sampling time for the depuration period showed significant



                                                                    17







                                                                                                Sericano et al. - 8


                    differences between the slopes, i.e. depuration rates, measured for Hanna Reef and Ship

                    Channel oysters were significantly different. The biological half-life, tj/2, can be derived

                    from equation (3)


                                                      4/2 = 0-693/kd                                   (4)


                         The half-lives are reported in Table 2. They ranged from 9 and 10 days for pyrene to

                    26 and 32 days for fluoranthene in Hanna Reef and Ship Channel oysters, respectively.

                    Most of the values were, however, between 10 and 16 days. These findings are in

                    agreement with those of Pruell et al. (1986) who reported half-lives between 14 and 30 days

                    for selected PAHs in mussels (Mytilus edulis) exposed in the laboratory to environmentally

                    contaminated sediments. Contrasting with other reports (Table 1), both studies suggest that

                    bivalves are able to depurate the accumulated hydrocarbons in fairly short periods of time.


                         The difference in depuration rates between both newly and chronically contaminated

                    oysters is evident at the end of the 50-day depuration period when the concentrations of

                    PAHs grouped by number of rings or individually are compared (Fig. 4). At the end of the

                    depuration period, the total PAH concentration in chronically contaminated oysters were

                    about 40% higher than the final concentration measured in originally uncontaminated
                    oysters. Total PAH concentrations decreased from 4,400 to 360 ng g-1 and from 4,400 to
                    500 ng g-1, respectively. This observation is in agreement with an earlier work by Jackim

                    and Wilson (1977) who reported that the depuration rates of N' 2 fuel oil compounds

                    observed in chronically exposed bivalves (Mya arenaria) were considerably lower than those

                    observed in organisms after an acute exposure.


                    Polychlorinated Biphenyls


                         PCB concentrations in transplanted oysters increased from 30 ng g-1 to 850 ng g-1

                    after the 48-day exposure period. Pentachlorobiphenyls were the compounds accumulated

                    to the highest concentrations in transplanted and native oysters (Fig. 5). In comparison,


                                                               18







                                                                                                Sericano et al. - 9


                    practically no octa-, nona- or decachlorobiphenyls were detected in either oyster group.

                    Contrasting with PAHs, not all the PCB homologs measured in transplanted oysters reached

                    the concentration encountered in indigenous individuals by the end of the fust phase of this

                    experiment. While there were no statistically significant differences in the tri- and

                    tetrachlorobiphenyl concentrations measured in transplanted and native oysters, significant

                    differences were observed in the total concentrations of penta- and hexachlorobiphenyls. It

                    seems evident that a longer exposure period is needed for the higher molecular weight PCB,

                    i.e. congener 110, to reach an steady state concentration (Fig. 6).


                         Hanna Reef and Ship Channel oysters showed statistically significant depuration

                    (p<0.05) of low molecular weight PCBs when relocated to the Hanna Reef area. Originally

                    uncontaminated oysters depurated PCBs at a faster rate than chronically contaminated

                    oysters. The clearance rates of high molecular weight PCBs were significantly slower in

                    both oyster populations. This differential PCB depuration can be observed in Fig. 7 where

                    the concentrations of selected PCBs at the end of the uptake and depuration periods are

                    shown.


                         Biological half-lives (BHL) for selected PCB congeners in Hanna Reef and Ship

                    Channel oysters ranged from 22 to 130 days and from 22 days to >year, respectively (Table

                    2). These BHL compare well with those observed in previously reported studies using

                    bivalves. Pruell et al. (1986) reported half-lives for some tri-, tetra-, penta- and

                    hexachlorobiphenyls in mussels exposed to resuspended contaminated sediments ranging

                    from 16.3 to 45.6 days. Similar to the present study, the biological half-lives of PCBs

                    increased with the number of chlorine atoms in the biphenyl rings. Langston (1978) also

                    reported that the less chlorinated PCB congeners were depurated more rapidly by bivalves

                    (Cerastoderma edule and Macoma balthica) with half-lives from 5 to 21 days for selected

                    di-, tri- and tetrachlorobiphenyls. In contrast, the concentrations of hexachlorobiphenyls,

                    and some of the pentachlorobiphenyls, did not decrease during the 21 -day study. Courtney




                                                               19







                                                                                                  Sericano et al. - 10


                    and Denton (1976) reported that environmentally contaminated clams and clams exposed to

                    Aroclor 1254 in the laboratory did not depurate PCBs during three months in control

                    seawater.



                          From this study, it is clear that oysters will react differently to sudden increases in

                    environmental concentrations of PAHs or PCBs,.as a consequence of, for example,

                    accidental spills. While PAHs and low molecular weight PCB concentrations seem to reach

                    a steady-state within about a month, high molecular PCB congeners might require a much

                    longer period of time, i.e. over 6 months to reach steady-state concentrations. Similarly, the

                    period of time needed for oysters to depurate the accumulated organic contaminants after the

                    spill to accurately represent the actual contamination of a site will be different for PAHs and

                    lower chlorinated PCB congeners compared to higher molecular weight PCBs.


                          As a general conclusion oysters can be useful tools in biomonitoring studies but

                    results differ for different trace organic contaminants. Transplant studies place boundary

                    conditions on the use of oysters as sentinel organisms. These experimental results can be

                    used to better understand the PCB and PAH data in oyster samples collected from coastal

                    U.S. areas during programs such as NOAA's National Status and Trends (NS&T) "Mussel

                    Watch" Program.


                    ACKNOWLEDGEMENTS


                          Funding for this research was provided by the National Oceanic and Atmospheric

                    Administration Grant Number 50-DGNC-5-00262 (National Status and Trends Program).







                                                                                              Sericano et at. - I I




                   REFERENCES


                   Blumer, M., G. Souza and J. Sass, 1970. Hydrocarbon pollution of edible shellfish by an

                         oil spill. Mar. Biol., 5: 195-202.


                   Boehm, P.D. and J.G. Quinn, 1977. The persistence of chronically accumulated

                         hydrocarbons in the hard shell clam Mercenaria mercenaria. Mar. Biol., 44: 227-233.


                   Courtney, W. A. M. and G. R. W Denton, 1976. Persistence of polychlorinated biphenyls

                         in the hard-clam (Mercenaria mercenaria) and the effect upon the distribution of these

                         pollutants in the estuarine environment. Environ. Poll., 10: 55-64.


                   Farrington, J. W., E.D. Goldberg, R.W. Risebrough, J.H. Martin and V.T. Bowen, 1983.

                         U.S. "Mussel Watch" 1976-1978: An overview of the trace-metal, DDE, PCB,

                         hydrocarbon, and artificial radionuclide data. Environ. Sci. Technol., 17: 490-496.


                   Farrington, J.W., J. Albaiges, K.A. Burns, B.P. Dunn, P. Eaton, J.L. Laseter, P.L.

                         Parker and S. Wise, 1980. Fossil fuels. In: The International Mussel Watch, Report

                         of a workshop sponsored by the Environmental Studies Board Commision on Natural

                         Resources, National Research Council, pp 7-77.


                   Goldberg, E. D., V.T. Bowen., J.W. Farrington, G. Harvey, J.H. Martin, P.L. Parker,

                         R.W. Risebrough, W. Robertson, E. Schneider and E. Gamble, 1978. The mussel

                         watch. Environ. Conserv., 5: 101-126.


                   Jackim, E. and L. Wilson, 1977. In: Proceedings, 10th Annual National Shellfish

                         Sanitation Meeting, p. 27.


                   Krahn, M.M., C.A. Wigren, R.W. Pearce, L.K. Moore, R.G. Bogar, W.D. MacLeod, S-

                         L Chan and D.W. Brown, 1988. Standard analytical procedures of the NOAA





                                                                21







                                                                                         Sericano et al. - 12


                      National Analytical Facility. New HPLC cleanup and revised extraction procedures

                      for organic contaminants. Noaa Tech. Memo, 52 pp.


                lAngston, W. J., 1978. Persistence of polychlorinated biphenyls in marine bivalves. Mar.

                      Biol., 46: 35-40.


                MacLeod, W. D., D.W. Brown, A.J. Friedman, D.G. Burrows, 0. Maynes, R.W. Pearce,

                      C.A. Wigren and R.G. Bogar, 1985. Standard analytical procedures of the NOAA

                      National Analytical Facility, 1985-1986. Extractable toxic organic components.

                      Second edition, U.S. Department of Commerce, NOAA/NMFS. NOAA Tech.

                      Memo. NMFS F/NWC-92.


                Martin, M., 1985. State Mussel Watch: Toxic survillance in California. Mar. Poll. Bull.,

                      16:140-146.


                Obana, H., S. Hori, A. Nakamura and T. Kashimoto T, 1983. Uptake and release of

                      polynuclear aromatic hydrocarbons by short-necked clams (Tapes japonica). Water

                      Res., 17: 1183-1187.


                Phillips, D.J.H. 1980. Quantitative Biological Indicators, Their Use to Monitor Trace

                      Metals and Organochlorine Pollution; Applied Science, London, 1980.


                Pittinger, C.A., A.L. Buikema Jr., S.G. Homor and Young R.W., 1985. Variation in

                      tissue burdens of polycyclic aromatic hydrocarbons in indigenous and relocated

                      oysters. Environ. Toxicol. Chem., 4: 379-387.


                Pruell, R. J., J.L. Lake, W.R. Davis and J.G. Quinn, 1986. Uptake and depuration of

                      organic contaminants by the blue mussels (Mytilus edulis) exposed to environmentally

                      contaminated sediments. Mar. Biol., 91: 497-507.







                                                                                              Sericano et al. - 13


                  Risebrough, R. W., B.W. DeLappe, W. Walker II, B.T. Simoneit, J. Grimalt, J. Albaiges

                        and J.A.G. Regueiro, 1983. Application of the Mussel Watch concept in studies of

                        the distribution of hydrocarbons in the coastal zone of the Ebro Delta. Mar. Poll.

                        Bull., 14: 181-187.


                  Sericano, J. L., E.L. Atlas, T.L. Wade and J.M. Brooks, 1990. NOAA's Status and

                        Trends Mussel Watch Program: Chlorinated pesticides and PCBs in oysters

                        (Crassostrea virginica) and sediments from the Gulf of Mexico, 1986-1987. Mar.

                        Environ. Res., 29: 161-203.


                  Sericano, J.L., 1993. The arnerican oyster (Crassostrea virginica) as a bioindicator of trace

                        organic contamination. Ph.D. Dissertation, Texas A&M University, College Station,

                        Texas, U.S.A., 242 pp.


                  Stegeman, J.J. and J.M. Teal, 1973. Accumulation, release and retention of prtroleum

                        hydrocarbons by the oyster Crassostrea virginica. Mar. Biol., 44: 37-44.


                  Tanacredi, J.T. and R.R. Cardenas, 1991. Biodepuration of polynuclear aromatic

                        hydrocarbons from a bivalve mollusc, Mercenaria mercenaria L. Environ. Sci.

                        Technol., 25:1453-1461.


                  Tripp, B.W., J.W. Farrington, E.D. Goldberg and J.L. Sericano, 1992. International

                        Mussel Watch: the initial implementation phase. Mar. Poll. Bull., 24: 371-373.


                  Tavares, T.M., V.C. Rocha, C. Porte, D. Barce16 and J. Albaig6s, 1988. Application of

                        the Mussel Watch Concept in studies of hydrocarbons, PCBs and DDT in the

                        Brazilian Bay of Todos os Santos (Bahia)Mar. Poll. Bull., 19: 575-578.


                  Wade, T. L., E.L. Atlas, J.M. Brooks, M.C. Kennicutt II, R.G. Fox, J.L. Sericano, B.

                        Garcia and D. DeFreitas, 1988. NOAA Gulf of Mexico Status and Trends Program:





                                                                23







                                                                                       Sericano et at. - 14


                      Trace organic contaminant distribution in sediments and oysters. Estuaries, 11: 171-

                      179.
                Wormell, R.L. (1979). Petroleum hydrocarbons accumulation patterns in Crassostrea
                      virginica: analyses and interpretations. Ph.D. Dissertation, Rutgers University, NJ,

                      189 pp.










































                                                         24









                       Table 1. Results of different hydrocarbon uptake/depuration studies with bivalves reported

                                                               in the literature.



                       Bivalve             Exposure                 Observation                      Reference



                       Oysters            No 2 Fuel Oil            Little depuration             Blumer et al. (1970)

                                          (60 days)                after 180 days

                       Oysters            N* 2 Fuel Oil            Nearly complete               Stageman and Teal

                                          (49 days)                depuration in 28              (1973)

                                                                   days

                       Clams              Chronically              Slight depuration             Boehm and Quinn

                                          polluted                 after 120 days                (1977)

                       Oysters            Chronically              Nearly complete               Wormell (1979)

                                          polluted                 depuration with
                                                                 ,BHL--4.4 days
                       Oysters            PAHs                     Analytes below                Pittinger et al.

                                          (15 days)                detection limits              (1985)

                                                                   after 4 days

                       Mussels            PAHs                     Depuration with               Pruell and Quinn
                                          (40 days)                BFUL between                  (1986)

                                                                   14-30 days

                       Clams              PAHs                     No depuration                 Tanacredi and

                                          (2 days)                 in 45 days                    Cardenas (1991)










                                                                    25









                    Table 2. Biological half-lives of selected PAHs and PCBs in transplanted and indigenous
                                                          oyster@(-


                    Analyte                                 Oysters                       Musselsl
                                                 Hanna Reef        Ship Channel


                    PAHs

                    Phenanthrene                       -                   -                   -
                    Fluoranthene                     26                  32                  30
                    Pyrene                           10                  12                    -
                    Benzo(a)anthracene               13                  15                  18
                    Chrysene                         12                  16                  14
                    Benzo(e)pyrene                   12                  16                  14
                    Benzo(a)pyrrm                      9                 10                  15
                    Indeno[1,2,3-c,dlpyrene          10                  11                  16


                    PCBs
                      26                             22                  22                    -
                      28                               -                   -                 16
                      52                             27                  45                    -
                    101                              55                 116                  28
                    110                              45                 103                    -

                    118                              73                 299                    -
                    128                              76                 229                  37
                    149                              130               >year                   -
                    153                              51                 102                  46


                      Pruell et al., 1986














                                                          26









                                                           Figure Captions



                   Figure I- Galveston Bay tr-ansplantation sites.

                   Figure 2-   Total and selected individual polynuclear aromatic hydrocarbon concentrations (ng
                               9-1, dry weight) in Hanna Reef and Ship Channel oysters at the end of the 48-day

                               uptake period. Error bars represent one standard deviation from the mean (n = 4).
                   Figure 3-   Selected polynuclear aromatic hydrocarbon concentrations (ng g-1, dry weight) in

                               Hanna Reef and Ship Channel oysters during the uptake and depuration phases of

                               the study. Error ban represent one standard deviation from the mean (n = 4).

                   Figure 4-   Total and selected individual polynuclear aromatic hydrocarbon concentrations (ng
                               9-1, dry weight) in Hanna Reef and Ship Channel oysters at the end of the 50-day

                               depuration period. Error bars represent one standard deviation from the mean (n

                               4).
                   Figure 5-   Total polychlorinated biphenyl@ grouped by level of chlorination, and selected
                               individual congener concentrations (ng g-1, dry weight) in Hanna Reef and Ship

                               Channel oysters at the end of the 48-day uptake period. Number in parentheses

                               indicates level of chlorination. Error bars represent one standard deviation from the

                               mean (n = 4).
                   Figure 6-   Selected polychlorinated biphenyl concentrations (ng g-1, dry weight) in

                               Hanna Reef and Ship Channel oysters during the uptake and depuration phases of

                               the study. Error bars represent on e standard deviation from the mean (n = 4).
                   Figure 7-   Total polychlorinated biphenyy grouped by level of chlorination, and selected
                               individual congener concentrations (ng g- 1, dry weight) in Hanna Reef and Ship
                               Channel oysters at the end of the 50-day depuration period. Number in parentheses

                               indicates level of chlorination. Error bars represent one standard deviation from the

                               mean (n = 4).





                                                                  27











                                                                                                             94@O-


                                                                                                   TEXA S


                                                                               A




                                                                      A


                    LA PORTE
                                                               A
                                         fA





                                                    <01
                                                     @P

                                                         0
                                                                                 EAST

                29*30'
                                            EO't
                                      SAN L




                                        7:
                                                                                 5z,




                                        TEXAS CITY


                                                               4M>:






                                                                      GALVESTON






                                 A

                                                                     Site 1              Hanna Reef

                    E
                 w                                                   Site 2: Ship Channel







                                                                    28








                             44W                     END OF UPTAKE PERIOD
                         z                                           N HR Oysters
                         0   3000                                    0 SC Oysters


                         z   2A0W0


                         z
                         0   1000



                                 0
                                      2         3         4         5         6

                                               NUMBER OF RINGS




                                                     END OF UPTAKE PERIOD
                             2500 B                              IL-Phenanthrene
                                                                 2-Fluoranthene
                         z                                       3-PyTene
                         0   2000,                               4-Senw(a)anthmcene
                                                                 5-Chrysene
                             1500                                6-Benzo(e)pyrene

                         z   1000

                         z
                         0     500


                                 0
                                      1       2       3        4       5        6

                                                     ANALYTE
                                 L




                                                 29











                                                                                              PYRENE
                               10000    A
                                                                                                  HR Oysters
                                                                                                  SC Oysters
                           z
                           0

                                 11000


                           (64
                           z


                                 100.
                           z
                           0



                                                     UPrAKE                           DEPURATION
                                    10  ....................I....... . . . ...................... ...........
                                       0     10      20      30    44)     50      60     70      80     90     100
                                                                   TIME       (days)


                                                                                            CHRYSENE
                                10000
                                        B                                                  0-     HR Oysters
                                                                                           0      SC Oysters
                           z
                           0


                                 1000



                           z


                           Z      loo
                           0
                           Q


                                                     UPrAKE                           DEPURATION
                                    10  .......                             low I
                                       0     10      20      30    40      50      60     70      80     90     1;0
                                                                   TIME (days)
                                                     u












































                                                                  30








                              4W                END OF DEPURATION PERIOD
                                   A                                  N HR Oysters
                         z                                            Im SC Oysters
                         0
                              300




                              200
                         z

                         Z    3LOO
                              100

                                0 FWIA
                                       2         3         4         5         6

                                               NUMBER OF RINGS




                                               END OF DEPURATION PERIOD
                              160- B                               IL-Phenanthrene
                         z    140-                                 2-Fluaranthene
                                                                   3-Pyrene
                         0                                         4-Be            ne
                              120                                  5-Chrysene
                              loo                                  6-Benzo(e)pyrene

                               so
                         z
                               60
                         Z     40
                         0
                               20

                                 0
                                      1        2       3       4        5       6

                                                     ANALYTE














                                                  31







                                         6w    A                        END OF UPTAKE PERIOD
                                                                                             0 HR Oysters
                                   Z     Sw                                                      SC Oysters
                                   0

                                         400


                                         300
                                   z
                                   W
                                   0     200
                                   z
                                   0     JLoo
                                             0                                               RTMM
                                                    3          4          5          6           7          8

                                                          LEVEL OF CHLORINATION




                                                                        END OF UPTAKE PERIOD
                                         100-   B

                                   z
                                   0       so-


                                           60

                                   z       40

                                   z
                                   0       20-


                                             0
                                                 26(3)       52(4) 110(5) 118(5) 149(6) 187(7)
                                                                  PCB CONGENER












                                                                                                  PCB 52
                                  loomo  A
                                                                                              0     HR Oysters
                                                                                              0     SC Oysters
                             z
                             0

                                   1100



                             z


                                     10
                             z
                             0


                                                      UPTAKE                             DEPURATION

                                        0     10      20      30     40      50       60     70     so      90     100
                                                                     TIME       (days)

                                  1000                                                           PCB 110
                                         B                                                          HR Oysters
                                                                                                    SC Oysters
                             z
                             0

                                    100



                             z


                                    10,
                             z
                             0



                                                      UPTAKE                             DEPURATION

                                        ..........     ..........                              .........      ..........
                                        0      10     20       30    40      50       60     70     so      90     100
                                                                     TIME (days)








                              600             END OF DEPURATION PERIOD
                                  A                                 0 HR Oysters
                         Z    SW                                    0 SC Oysters
                         0
                              4W


                              300
                         z
                         94
                         ri   200
                         z
                         0    100

                                 0
                                     3       4        5       6       7       a

                                          LEVEL OF CHLORINATION




                                              END OF DEPURATION PERIOD
                              loo  B

                         z
                         0     80"


                               60


                         z
                               40

                         z
                         0     20
                                0-         WA              MW
                                    26(3)   52(4) 110(5)    118(5) 149(6)    187(7)
                                                PCB CONGENER














                                                 34














                         Reprint 2


        Toxicological Significance of Non-, Mono-
         and Di-ortho-Substituted Polychlorinated
         Biphenyls in Oysters from Galveston and
                        Tampa Bay

          Jose L. Sericano, Stephen H. Safe, Terry L.
                  Wade and Jame M. Brooks




                                                                                                                                               ETC 192

                                                                                                 EnvironmenW Toxicoicigy and Chemistry. Vol. 13. No. 11, pp. 000-", 1994
                                 PeMainon                                                                                                           COP.-ght t 1994 SETAC
                                                                                                                                                            Printed in ine LSA
                                                                                                                                                     0730-'268/9L4 S6.00 - 00
                                                                                    0730-7268(94)00125-1



                                           TOXICOLOGICAL SIGNIFICANCE OF NON-, MONO- AND
                                           DI-ortho-SUBSTITUTED POLYCHLORINATED BIPHENYLS
                                                IN OYSTERS FROM GALVESTON AND TAMPA BAYS

                                       Jost L. SERICANO,*t STEPHINH. SAYE,* TE"y L. WADEt and JAm:Es M. BROOKSt
                                           +Geochemical and Environmental Research Group, College of Geoscience and Maritime Studies,
                                                        Texas A&M University, 833 Graham Road., College Station. Texas 77945
                                              :Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine.
                                                                    Texas A&M University, College Station. Texas -7843

                                                                    (Received 22 October 1993@ Accepted 14 April 1"4)


                            Abstr2ct -Concentrations an non-ortho (77, 126, and 169), mono-ortho (105 and 118) and di-ortho 028 and 138) -substituted
                            PCB congeners were measured in oysters from Galveston and Tampa bays, and reported toxic equivalent factors were used to
                            assess their toxicity. Most of Elie relative toxicity encountered in the oysters analyzed during this Study was due to the presence
                            of planar non-ortho-PCBs (53.8-94.307c), particularly congener 126. In contrast. the contribution of di-onho-substituted PCB
                            congeners to the total relative toxicity of the samples is negligible (< 1076). On average. the contribution of each of these non-.
                            mono-. and di-ortho-substituted PCB congeners to the total toxicity encountered in oysters from Galveston and Tampa bays
                            were 126 > 118 a 169 2t 105 > 77 z, 138 > 128 and 126 > 118 > 169 2: 77 > 105 v 138 > 128. respectively. Based on the re-
                            ported lower clearance rates of non-orEho- and mono-orEho-substituted PCB congeners compared to other congeners within the
                            same chlorination level. contaminated oysters that are depurated in clean environments will lower their total PCB concentra-
                            tions. but their original toxicity may not be proportionally reduced.

                            Keywords-PCBs            Toxicity      Depuration         Oysters     Gulf of Mexico



                                              INTRODUCTION                                           toxic but far more abundant mono- (PCB 105 and 118) and
                        The general concern about the occurrence of PCBs in dif-                     di-ortho (PCB 128 and 138) congeners.
                    ferent environmental compartments is associated with their                                         MATERIALS AND METHODS
                    potential adverse environmental and human health effects.                        Sampling
                    The toxicity of individual PCB congeners is structure-                               These samples were collected from 3 stations at 11 pre-
                    dependent [1-31, and the most toxic PCB congeners- i.e., the                     selected sites in Galveston and Tampa bavs (Fig. 1) durine
                    planar 3.3',4,4'-tetrachlorobiphenvi (7), 3,3',4.4',5-penta-                     the 6-year sampling activities of the National Oceanic and Al-
                    chlorobiphenyl (126). and 3.3',4.4",5,5'-hexachlorobiphenN.1
                                                                                                     mospheric Administration's (NOAA's) National Status and
                    (169)- are approximate iscistereomers and potent mimics of                       Trends -Mussel Watch" Program (December 1990-Januarv
                    :.3.7,8-telTachlOTodibenzo-p-dioxin (TCDD). TCDD and                             I"l). Distances between stations within each site varied from
                    related compounds elicit a diverse spectrum of toxic and bio-                    100 to 1,000 m. Depending on water depth. oysters 120 per
                    chemical responses including body weight loss, dermal dis-                       station) were collected by hand, tongs. or dred'ge. pooled in
                    orders, liver damage, thymic atrophy, reproductive toxicity
                                                                                                     precombusted jars, and frozen until analysis. More details
                    and immunotoxicitv, and the induction of CYPIAI and                              regarding site locations and sample collections for this PTO-
                    CYPIA2 gene expression [1-41. Although epidemiological                           gram are given elsewhere [I I)'.
                    studies on human and animal populations have not revealed
                    clear evidences of the carcinogenicity of PCBs under envi-                       F-viraction and initial sample fractionation
                    ronmental exposure, PCBs are strong promoters of hepatic                             The analytical procedure used for the extraction. initial
                    carcinogenesis in laboratory rodents 15).                                        fractionation', and cleanup of oyster tissue samples for the
                        In recent years there has been considerable interest in                      analysis of polychlorinated biphenyLs (PCBs), including pla-
                    studying the occurrence of not only planar PCB congeners                         nar PCB congeners, is based on a method developed by
                    but also their mono- and di-ortho derivatives 16- 101. The ob-                   MacLeod et a]. 1121 with a few modifications. Details of this
                    jective of this study was to determine the toxicological sig-                    method and its modifications have been fully described else-
                    nificance of three highly toxic planar PCB congeners (i.e..                      where 1131 and only the important steps will be given here.
                    PCBs 7. 126, and 169) encountered in oyster samples from                             Approximately 15 g of wet tissue are extracted. after the
                    Galveston and Tampa bays compared to the'relatively less                         addition of anhy'drous Na,SOA, with methylene chloride
                                                                                                     using a homogenizer (Tekmar Tissurnizer). A small subsam-
                                                                                                     pie is removed from the total volume for lipid determination.
                        'To whom correspondence may be addressed.                                    Each set of 8 to 10 samples is accompanied by a complete
                                                                                                 36








                  zmoN                                                              T E X A S                                                 A - OLD
                                                   A                                                                                          B - KNIGH
                                                                                                                                              C - PAPYS
                                                                                                                                              D - NARVA
                                                                                                                                              E - COC
                                           "Omit                  to
                                                                                                                                              F   muuz




                                                            tp                                                        Q
                                                                                St                                        ounockn..
                                                                                            2 36

                                                             C
                                                                                                                         clewwaw-.
                                                                                                                                          0






                                                                                                                                                        *T

                                                        E
                                                                                                                                                 c
                                                                 F
                                                6,4                                                      GULF              s  Polersbur
                                         wisIt
                                                      A - SHIP CHANNEL                                    OF
                                                      0 - TACHT CLUB
                                                                                                                                          Pkm@"
                                                      C - TODWS DUMP
                                                         - HANNA REEF
                                                      D
                                                                                                        MEXICO                     cb
                                                      E - CONFEDERATE REEF
                                                      F. - OFFATS nAyou




                                                                                                                                Ann&
                                                                                                                                Mafia Ishw-d
                      0-










                                                              Significance of toxic PCBs in Gulf of Mexico oil                                          003


                    system blank and spiked blank or reference material carried           the oven temperature was programmed from 100 to 1500C
                    through the entire analytical method as part of the labora-           at 100C min-' and from 150 to 2700C at VC min-' with
                    P
                    ory quality assurance/qualiry control (QA/QQ procedure.               I-min hold time at the beginning of the program and before
                    Before extraction 4,4'-dibromoocmfluorobipheny) (DBOFB),              the program rate change. A hold time of 3 min was used at
                    CB 103, and PCB 198 are added to all samples, blanks, and             the final temperature. Total run time was 30 min.
                    reference material as internal standards. Tissue extracts are            In both analyses, injector and detector temperatures were
                    initially fractionated by partially deactivated silica: alumina       set at 275 and 325*C, respectively. Helium -as used as the
                    column chromatography. The sample extracts are eluted                 carrier W at anowvelocity of 30.0 cm sec ` at I 00"C. A
                    from the column using pentane (f I = aliphatic hydrocarbons)          mixture of argon/methane (95: 5) was used as the makeup gas
                    and pentane: methylene chloride (1: 1) M = chlorinated hy-            at a flow rate of 20 ml min-'. The volume injected was 2jul.
                    drocarbons and PAHs). The second fractions are further pu-               The PCB congeners were quantitated against a set of stan-
                    rified by high-performance liquid chromatography to remove            dards injected at four different known concentrations to cal-
                    lipids [14). Finally, sample extracts are concentrated to a           ibrate the instrument and to compensate for the nonlinear
                    olume of I ml, in lexane, for gas chromatographic IGCI                response of the elec,ron,cap,ure detector. Te,rachloro-m-
                    analysis.                                                             xylene (TCMX) was used as the GC internal standard to es-
                                                                                          timate the recoveries of the internal standards- The detection
                    Isolation of planar PCB congeners                                     limits for individual planar and nonplanar PCB congeners -
                      The extraction, initial fractionation, and cleanup of pla-          estimated on the basis of 2.5 g (dry weight) oyster tissue sam-
                    nar PCBs were performed simultaneously with the bulk of               ple sizes, I in) final extract volume, and 2 gl of the extract
                    the ortho-substituted PCBs. After the final extract concen-           injected into the GC-ECD -are 0.25 ng g -' and 0.05 ng
                    tration to I in], a 0.25-ml fraction was withdrawn for the            9-', dry weight, respectively.
                    analysis of planar PCB congeners. Because of the low envi-
                    ronmentaJ concentrations expected for planar PCBs, the ex-                             RESULTS AND DISCUSSION
                    tracts Of Oysters collected at the same site were combined as            Concentrations of individual planar PCB congeners. as
                    one sample. Thus, the concentrations of planar PCB conge-             well as concentrations of related mono- and di-ortho-
                    ners represent the analyses of composite samples. Before pro-         substituted congeners and total PCBs, in oyster samples from
                    ceeding to the next step, PCB 81 was added to the extracts            12 sites in Galveston and Tampa bays are shown in Table 1.
                    as internal standard for planar PCB congeners.                        These concentrations have been corrected by the recoveries
                      The methodology used to isolate planar PCBs in tissue               of the internal standards -i.e., PCB 103 for orEho-substituted
                    samples has been published elsewhere (151. Briefly, glass             congeners and PCB 81 for planar congeners. In general. re-
                    chromatographic columns (10 min i.d.) are packed in meth-             coveries of the internal standards ranged from 61; to 9207o.
                    ylene chloride. Two grams of a 1:20 mixture of activated                 The highest concentrations of planar PCBs in samples
                    AX-21 charcoal (Super-A activated carbon) and LPS-2 silica            from Galveston Bay were found in oysters collected in the
                    gel (low-pressure silica gel, particle size 37-53,um, 450 m2.         area where the Houston Ship Channel enters into Galveston
                    g-'), are packed between two layers of anhydrous sodium               Bay and the concentrations decreased seaward. High planar
                    sulfate. Oyster Eissue extracts are sequentially eluted from the      PCB levels were also encountered in samples from a site near
                    column with 50 ml of 1:4 methylene chloride and cyclohex-             the city of Galveston. In general. the levels of planar PCBs
                    ane, 30 ml of 9:1 methylene chloride and toluene. and 40 ml           in Galveston Bay were clearly highest near population cen-
                    of toluene. The first two solvent mixtures are collected as one       ters. The same correlation was observed in Tampa Ba%.
                    fraction 1111 and contain the ortho-substituted PCB conge-            where the highest planar PCB concentrations were observed
                    ners. The second fraction M), containing the non-ortho-               in samples collected near the city of Tampa.
                    substituted PCB congeners with four, five and six chlorines              The concentrations of congener 77 in different commer-
                    in meta and para positions, is concentrated to a final volume         cial PCB mixtures are I to 2 orders of magnitude higher than
                    of 0.05 ml, in hexane, for gas chromatography-electron-               the concentrations of congener 126 and 3 to 5 orders of mag-
                    capture detection (GC-ECD) analysis.                                  nitude higher than the concentrations of congener 169 [16-
                                                                                          201. Comparatively, average concentrations of congener -7
                    Instrumental ana@vsis                                                 encountered in oyster samples from Galveston and Tampa
                      The PCBs. both planar and nonplanar congeners, were                 bavs were 1.5 to 2 times higher than the concentrations of
                    analyzed by fused-silica capillary column. 30 in long x               PC*B 169 but comparable to the concentrations of congener
                    0.25 mm i.d. with 0.25 14m DB-5 film thickness, GC-ECD                126. These results suggest that congeners 126 and 169 are en-
                    (61M) using a Hewlett Packard 5880A GC in the splitiess               riched in oyster samples from Galveston and Tampa bays.
                    mode.                                                                 Selective enrichment of congener 126 and 169 with respect
                      For the analysis of ortho-substituted PCB congeners, the            to congener 77 is also apparent in mussels and oyster sam-
                    oven temperature was programmed from 100 to 140*C at                  ples analyzed by different researchers (Table 2). This selec-
                    5*C min-', from 140 to 2500C at 1.50C min-', and from                 tive enrichment might be a consequence of the increasing log
                    250 to 300*C at 100C min-' with 1-min hold time at the be-            K,,. (logarithm of the octanol/water partition coefficient)
                    ginning of the run and at each program rate change. A hold            with the number of chlorines substituted in the biphenyl rings
                    time of 5 min was used at the final temperature. Total run            (6.36, 6.89, and 7.42 for congeners 77. 126. and 169, respec-
                    time was 94 min. For the analysis of planar PCB congeners             tively, Hawkerand Connell 1211). Inaddition, themore highl%


                                                                                       38











                         004                                                                             I.L. SERICANO Er AL.


                                   Table 1. Non-. mono-, and di-ortho-substituted PCB and total PCB concentrations (ng S-' dry weight = I sD) in oysters
                                                                                (Cramosiree virginica) from Galveston and Tampa bays

                                                                                                         PCB congeners
                                                                       Non-ortho                         Mono-ortho                            Di-ortho                     Total PCB           Total        Total
                         Sample                            77          126             169               105            118              128                138        concentrations" TEQs6                 TEQs-

                         Galveston Say
                            Ship Channel                   2.0         2.2             0,79              39 = 4.1    48 = 5.8          4.4 = 0.6         50 = 6.7           1, 100        120      280           370
                                                           (20)        (220)           (40)              (39)           (48)             (0.0             0.0)
                            Yacht Club                     0.33        0.21            0.19              4.1 = 1.7   9.0 = 0.3         1.5 = 0.2         13 = 3.2           210           14        34           47
                                                           (3.3)       (21)            (9.5)             (4.1)          (9.0)          (<0. 1)            (0-3)
                            Todd's Dump                    0.14        0. 1 1.         0.05              1.3 = 0.2   5.2 = 1.0         0.6 = 0.2         5.7 = 1. 1         110= Is                 16           23
                                                           (1.4)       (12)            (2.7)             0 -3)          (5-2)            (0.0             (0-1)
                            Hanna Reef                     0.09        0.11            0.09              0.6 = 0.5   1.2 = 0.3         0.6 = 0.2         4.3 = 0.8          50 = -.0                16           18
                                                           (0.9)       (11)            (4.5)             (0-6)          (1.2)          (<O. 1)            (0.0
                            Confederate Reef               0.10        0.09            0.05              0.7 = 0.6   2.8 = 0.2         0.7 = 0.3         3.0 = 1.4          77 = 9.6                13           1-1
                                                           0.0)        (9.4)           (2.6)             (0.-)          (2.8)          (<O. 1)            (0.0
                            Offats Bayou                   0.50        0.40            0.09              3.2 = 1.8   10 = 2.'          1.0     0.3       8.7 :t 3.4         160           44        50           63
                                                           (510)       (40)            (4.7)             13-22)         (10)                              (0.2)
                         Tampa Bay
                            Old Tampa Say                  0.17        0.32            0.28              0.4 = 0.2   -1.4 = 1.6        0.2     0.2       4.0 = 0.8          55            8.5       48           51
                                                           0 .'?)      (32)            (14)              (0-4)          (2.4)          (<O. 1)            (0-1)
                            Knight Airport                 1.5         0.33            0.08              7.6 = 3.7   36 = 15           Z.0 = 1.0         30 = 13            580           230       5            97
                                                           (15)        (33)            (4.2)             (77.6)         (37)           (<0.1)             (0-6)
                            Papys Bayou                    0.09        0.10            0.05              0.4 = 0.1   3.0 = 0.'?        0.3 = 0.2         6.1 = 2.6          75            27        1.4          1
                                                           (0.9)       (10)            (2.6)             (0.4)          (3-0)          t<0.1)             (0.1)
                            Narvaez Park                   0.26        0.14            0.15              1.3 = 0.2   '.3 = 1.8         0.6 = 0.2         8.9 = 3.1          120           31        24           33
                                                           (2.6)       (14)            (7-5)             (1.3)          (7.3)          (<0.0              (0.2)
                              ockroach Bay                 0.20        0.29            0. J0             0.4 = 0.2   3.0 = 1. 1        0.2 = 0.'         2.8 = 1.:          49            20        36           40
                                                           (1.0)       (29)            (5-0)             (0.4)          (3-0)          (< 0. 1)           (0-1)
                            Mullet Key Bayou               ;D          ND              ND                0.3 = 0.2   1.6 1 0.3         0.2 = 0.1         3.3 :t 2.0         38            14        -            1.0
                            C



                                                                                                         (0.3)          (1.6)          (<0. 1)            (0.1)

                          Total :.3.'%8-TCDD equivalents (TEQs) are expressed in pg g-1                           dry weight. Individual 2.3.7.8-TCDD equivalents are given in parentheses.
                          ND. none detected.
                         'Equal to the sum of all the measurable individual congeners.
                         bToW TCDD equivalent@ corresponding to the non-oriho-substituted PCB congeners.
                         'Total TCDD equivalents corresponding to (he sum of congeners 7, 126. 169, 105. 118, 1_28. and 138.


                         chlorinated 126 and 169 isomers are more resistant to meta-                                        to 1.40076 of the total PCB load in Galveston and Tampa
                         bolic and chemical breakdown compared to the lower chlo-                                           bays, respectively.
                         rinated PCB 77, [1]. On average, the sum of these three highly                                          As expected from the small contributions of planar con-
                         toxic congeners ranged from 0.26 to 0.62176 and from 0.31                                          geners to the total commercial PCB mixtures (16-201, these


                                                           Table 2. Concentrations of selected non- and                     mono-ortho-iubstituied PCB congeners
                                                                                             in bivalves reported in the literature

                                                                                                                  PCB congeners (pg.,& dry wt.)
                                                                                                                  Non-oriho                      Mono-ortho                     Reference
                                                 Species               Location                  77               126            169           105              118                       no.

                                                 Mussels'          Hong Kong                     590              <33            <4. 7                                                    (71
                                                                                                 (88)             (<5.0)         (<0.7)
                                                 Mussels'          Hong Kong                     4,700            330            45                                                       (71
                                                                                                 (700)            (49)           (6.8)
                                                 Mussels           Long Island                   400                                           3.300          8,000                       124)
                                                 Mussels'          Eastern Scheldt               430              87             12            2.900          10,000                      110)
                                                                                                 (64)             (13)           (1.8)         (430)          (1.500)
                                                 Oysters'          Eastern Scheldt               200              40             7.3           1,900          4,500                       1101
                                                                                                 (30)             (6-0)          0. 1)         (280)          (680)
                                                 Oysters           Galveston Bay                 530              520            211           8.200          13.000            This studv
                                                 Oysters           Tampa Bay                     370              200            110           1.700          8.900             This studv"

                                                 Reported concentrations were recalculated on dry-weight                         basis usine   15074 dry weight.       Original concen-
                                                 trations are indicated in parentheses.


                                                                                                                            39











                                                               Significance of toxic PCBs in Gulf of Mexico oiql                                          005

                   congeners were detected at much lower concentrations than              as well as their totals are fisted in Table 1. In Tampa and Gal-
                   some mono- and dqi-ortho-substqituted PCB congeners -e.g.,               veston bays, the total TE0qQs ranged from 13.5 to 52.qZ qpqg g-'
                   q105, q1q1q1, q12q1, and 138. Individually, the concentrations of            and from 13.0 to 280 pqg qg-, respeqaively. The data indicate
                   these mono- and di-ortho congeners in oyster samples from              that, except for the sample collected near the Houston Ship
                   Galveston and Tampa bays were I to 2 orders of magnitude               Channel in Galveston Say, the TE0qQs in oysters from Tampa
                   higher than planar PCB concentrations (Table 1).                       and Galveston bays were similar. Oysters collected near the
                                                                                          Houston Ship Channel in Galveston Bay were clearly the
                   0qTCDD equivalents                                                       most toxic.
                      In a review, Safe q(3q1 discussed the environmental and                   Mono- and di-ortho-PCB congeners, derivatives of pla-
                   mechanistic considerations behind the development of the               nar PCB congeners, are relatively less toxic but far more
                   toxic equivalent factor q(TEqF) concept. Safe proposed pro-              abundant in environmental samples than their parent com-
                   visional TEF values of 0.01, 0. 10. and 0.05 for planar PCB            pound and might, therefore. have a significant toxic environ-
                   congeners 4q7q7. 126, and 169, respectively. Similarly, Safe pro-         mental impact. To assess the environmental significance of
                   posed provisional TqEF values of 0,00q1 and 0.000q12 qfor                  these congeners in terms oqf TCDD-qIqle effects in oyster am-
                   mono- and di-ortho-chqlorine-suqbstituted PCB congeners, re-             pies from Galveston and Tampa bays. the calculated q2.3,7,8-
                   spectively. Recently, the validation and limitations of these          TCD0qD equivalents corresponding to congeners 105, 118, 12q8,
                   factors have been discussed q122q). These TEF values are used            and 138 were compared to those corresponding to planar
                   t
                   o convert the analytical results in TCDD or toxic equivalents          congeners (Table 1). Contribution of congeners 105 Plus 118
                   116q(TEQsq) where                                                           to the total TEQs was as high as 45.4016. In contrast, the con-
                                                                                          tribution of di-ortho congeners to the total toxicity of the
                                    TEQ           qQPCBq1j - TEF,q)                          samples is negligible q(< 1 .007cq). The lesser toxicity of the di-
                                                                                          ortho congeners is a consequence of their reduced TC0qDD-
                   and i represents the individual PCB congener.                          like activity rather than lower concentrations. Congeners '    '77,
                      Calculated TEQs for the planar PCB congeners, in pqg g-',            126, 169, 105, and I 18 accounted for over 9q04qMo of the total
                   in oyster tissues collected from Galveston and Tampa bays              TEQs encountered in a variety of biota samples [8, 1 qO.qZ3,-'4q1.




                                                        3                                                             A




                                                        4     PCs 77 0


                                                   vc


                                                                   Pqa lie
                                                   -Z   5- Ica I= 0    -              q-





                                                        6
                                                        0.00         0.01         0.02        0.03        0.04         0.05

                                                                                     k* (days


                                                        3.                                                             B




                                                        4q,                                       q0 qPqCqa q7q7


                                                   A!


                                                                                        qWq2 its
                                                   q%    5q.                                                  qP8qM q&4qW
                                                                                     PCs Ica





                                                          0       20       q40        q6q0      so       100      120      1q40

                                                                                     qSHL (days)


                   Fig. 4q2q. Depuraqtqion constant q(kd) and biological half-lives qtBHLq) of planar congeners compared to ranges qaqf qvaluqcq@ calculated for nonpqla-
                   nar PCBs. V4qiqluqeqs for selected mono-orqtqho-q@chlorine-subsqtituted congeners relevant to this quudqy are also q@hownq.


                                                                                          40
 












                        Most of Elie relative PCB toxicity encountered during this                  vironmental Toxicology. Springer- Vqerlag, New York, NY, pp.
                    study was associated with the presence of planar PCBs, par-                     77-95.
                     cuqlarqly congener 126. In a recent study, Sericano et al. 1251              6.  de Voogi, P., D.E. Wells. L. Rettlerqgardill and qU.A. Th. Brink.
                                                                                                    man. 1990. Biological activity, determination and occurrence of
                    reported that planar PCBs 77q7 and 126 were depurated from                       planar, mono- and di-orLho PCBS. qInif. qJ. qEirviron. Anal. Chem.
                    the oyster tissue at a significantly lower rate than other PCB                  40:1-46.
                    congeners within the same level of chlorination. That report                7.  qKannan. N.. S. Tanabe. R. Tausqkaws and D.J.H. Phillips.
                    confirmed the findings of a previous study with transplanted                    1989. Persistence of highly toxic coplanar PCBs in aquatic eco.
                                                                                                    systems: Uptake and release kinetks of coplanar PCBs in green-
                    mussels M. However, not only the planar PCB congeners but                       lipped mussels (Perna viridis Linnaeus). qEnviron. Poqfqtr. 55:
                    also their mono-ortho derivatives show slower depuration                        65-76.
                    rates than the bulk of PCB congeners in the corresponding                   8.  Schwartz. T.R.. D.E. Tiqdqlitt. qK.P. Feltz and P.H. Peterman.
                    Level of chlorination (Fig. 2). This might be of significant im-                1993. Determination of mono- and non-o,o'-chqlonne substituted
                    portance in projects such as the Mississippi oyster relaying                    poqlychlorinated biphenyls in Arocqlors and environmental sam-
                                                                                                    ples. Chemosphere q26:1443-1460.
                    effort designed to transplant oysters from polluted to clean                9.  Wells, D.E. and 1. qEcharri. 1992. Determination of individual
                    waters for a period oqf time before harvesting them for hu-                      chlorobiphenvis (CBsq), including non-ortho, and mono-oriho
                    man consumption [26]. Bohern and Quinn [27q1 reported that                       chloro substituted CBs in marine mammals from Scottish wa-
                    transplanting of shellfish from polluted to cleaner envqiron-                    ters. Int. qJ. qEnviron. Anal. Chem. 47:75-97.
                                                                                               10.  de Boer. J.. C.J.qN. Stroack. W.A. Tmag and qJ. van der Meer.
                    ments has been used as a means of increasing harvestable                        1993. Non-ortho and mono-ortho substituted chiorobiphenyis
                    yields of the hard-shell clam q(Mercenarqza mercenaria) in Nar-                   and chlorinated diqbenzo-p-0qdoxins and dibenzofurans in marine
                    ragansett Bay, Rhode Island. However, oysters that are al-                      and freshwater fish and shellfish from the Netherlands. Chemo-
                    lowed to depurate in a clean environment might show lower                       sphere q26:1823-1842.
                    concentrations of PCBs but still may retain significant                    11.  Serkano. J.L.. T.L. Wade. J.M. Brooks. E.L. Atlas. R.R. Fay
                                                                                                    and D.L. Wilkinson. 1993, National Status and TrendsqMussel
                    amounts of the highly toxic congeners.                                          Watch Program: Chlordane-related compounds in Gulf of.4qMex-
                                                                                                    ico oysters, 1986-90. Environ. Pollut. q82:q23-32.
                                   SUMMARY AqND CONCLUSIONS                                     12.  MacLeod. W.D.. el al. 19q8q5. Standard analytical procedures of
                                                                                                    the NOAA National AnaJytqicaq) Facility, 1985-1986. Extractable
                        The total TEQs in oyster samples from the Gulf of Mex-                      7oxic Organic Components, 2nd ed. NOAA Technical Memo-
                    ico were estimated from the concentrations of planar PCB                        randum NMFS F/NWC-92. U.S. Department of Commerce,
                    congeners-i.e., 7q7, 126, and 169-and two mono-ortho-                            Washington. DC.
                    substituted PCB congeners - i.e., 10q5 and I 18 - using pub.                13.  Sericano. J.L.. E.L. Atlas. T.L. Wade and J.M. Brooks. 1990.
                                                                                                    NOAA's Status and Trends Mussel Watch Program: Chlorinated
                    qlished TEF values. As it has been discussed in previous                         pesticides and PCBs in oysters (qCrassostrea virginica) and sed-
                    studies for a variety of biota samples, most of the relative                    iments from the Gulf of mexico. 1986-1987..0qWor. Environ. Res.
                    PCB toxicity detected in oyster tissues was associated with                     29:161-203.
                                                                                               14.  qKrahn.0qM.M., et W. 1988. Standard analytical procedures of the
                    these congeners. The slower depuration rates reported for                       NOAA National Analytical Facility. 198'8. New qHPLC cleanuc
                    these congeners compared to other PCBs within Elie same                         and revised extraction procedures for organi   Ic contaminants ..
                    level of chlorination suggest that most of the toxicity would                   Technical qMernorandurn. National Oceanic and Atmospheric
                    be retained by depurating oysters even though the total PCB                     Administration. Seattle. WA.
                    concentrations might have si'qgnqifqicantqly decreased. This might           1q5.  qSericano. J.L.. A.M. EI-Husseini and T.L. Wade. 1991. Isola-
                                                                                                    tion of planar polychlorinated biphenvis by carbon column chro-
                    have a significant effect on the applicability of some of the                   matography. Chemosphere q23:1541-1548.
                    shellfish industry practices such as oyster relaying.                      16.  Huckins. J.qN.. D.L. Suilling and J.D. Pett). 1980. Carbon-foarn
                                                                                                    Chromatographic separations of non-o.o'-chlorine substituted
                                                                                                    PCBs from Aroclor mixtures. qJ. Assoc. Off. Anal. Chem. 63:
                                              REFERENCES                                            750-75q5.
                                                                                               17.  qKannan. N., S. Tanabe. T. Wkirnoto and R. Tatsukawa. 198-
                     1  Safe, S.H. 1984. PoiN  chlorinated biphenyls q(PCBs) and poly-               Coplanar PCBs in Aroclor and Kanechlor mixtures. qJ. Assoc.
                        brominated biphenyls (PBBs): Biochemistry, toxicology and                   Off, Anal. Chem. 70:451-454.
                        mechanisms of action. CqRC Crit. Rev. qToqncol. 13:319-393.               18.  Duinker. J.C.. D.E. Schutz and G. Petrick. 1988. .14ultidimeri-
                        Goldstein. J.A. and S.H. Safe. 1989. Mechanism of action and                sional gas chromatography with electron capture detection for
                        struc(ure-activity relationships for the chlorinated dibcnzo-p-             the determination of toxic congeners in polychlorinated biphe-
                        dioxins and related compounds. In R.D. Kqimbrough and A.A.                   nyl mixtures. AriaL Chem. 60:47q8-482.
                        Jensen. eds.. Halogenated Bqipqheqiqtqyqlqs, 0qTeqrpqhenyqiqs, Naphthalenesq.        q19.  Schulz. D.E., G. Petrick and J.C. Duinkqer. 1989. Compqlqeqtqtq.
                        Dqi0qbqeqnzodioxins and Related Products. Elsevier, New York. NY.                characterization of polqychqlorqinqated bqiphqenqyl congeners in com-
                        pp. 239-293.                                                                mercqiaqJ Aqroc0qlor and Clorphqen mixtures by multidimensional gas
                     3. Safe. Sq.H. 1990. Poqlyqch0qloqrinated biphenvqiqs (4qPC8qBsq). dibqeqnzoq-p-               c0qhromaqtographyq-eqlecqtron capture detection. 2qEqnqvqiroqn. Scqiq. Tech-
                        dioxin, 8q1PCDDq,qlq, dibqenzoluran, 0qIqPCDFq,0q), qand related qcom,                    not. 23:0q152q-0q159q,
                        pounds: Environmental and mechanistic considerations which             20.  Anderson. J.W. 1991. Determination of congeners of poqlvcqhqloq-
                        support the development of toxic equivalency factors (TEFqs).                rinatqed bipherqyqis in reference materials. 0qJ. High 4qRqe5oiq. Chro-
                        C0qRC Cqrqit. Rey. 4qToxqicoql. 21:4q51-88q.                                           mqaqrogrq. 370:369-372.
                     4. Safe. Sq.H. 194q86. Comparative toxicology and mechanisms of              21.  Hawker. D.W. and D.W. Coqnqsqiqell. 104q"8. Octqaqnoql-waqter Parti-
                        action of poqlycqh0qlorinated dibenzo-pq-dioxins and dqiqbqeqnzofurans.              tion coefficients oqfq'poqlychlor0qinaqted bqiphqeny0ql congeners. 0qEqnvq,-
                        Annu. Rey. Pqhqarmqaco0ql. 4qToxicoql. 26:3q71-399.                                  qrqoqn. Set. 0qTecqhqnoqlq. 0q22:382-387.
                     5. Hayes. M.A. 1987. Carcinogenic and muqLagenic effects of                q22.  Safe. Sq.H. 1992. Development. validation and lqimqitaqtqiorqiqb of
                        PCBs. In S. Safe and 0q. Hutzqingqer, eds.. Environmental Toxin                toxic equivalency factors. Chemoqspqhqerqe q25:61-6q4.
                        4qSeqnqeqs q1, Pqo6q@qycqhql . .... wed qBipqhqnyqlqs q1PCqB:sq)q.q-,6qWqaqnq7mqaqlqian qaqnd Eqn-      23q,  Smith, L,Mq*q, T.R, Schwartz and Kq. qFeftzq. q10q904qw, Dqetem,n     q1,  'on



                                                                                          41
 








                                                                                                                                                              7

                       and occurrence of A4qHH-active polychlorinated biphenyls.                   1992. Environmental significance of the uptake and depuration
                       2,3.7,q1q1-qmtrachloro-p-dioxin and 2.3.7,q8-teirachlorodibenzofu-            of planar PCB congeners by the American oyster (Crassostrea
                       ran in Lake Michigan sediment and biota The question of their            virginica), Mar. Pollut. Bull. q24:537-543.
                       reistive toxicological significance. Chemosphere 21:1063-1085.       26.  Skupien. 8qL 1990. The great Mississippi oyster relay. Gulqfwalch
                   24. Hoag, C.S.. qB. Bush and J. Mao. 1992. Coplanar PCB in fish                2:4-5.
                       mussels from manne and estuarine waters of New York State.           27.  Boehm. P.D. and J.G. 4qQuiq". 19177. Tqhe persistence of chroni-
                       qEcotoxicoL Environ. qSaqf. q23:q)18-131.                                      cally accumulated hydrocarbons in the hard sheqfql claqmqWerce-
                   2q3. Swienw, J.4qL. T.L Wak, A.M. EqI-qHosseqmi and qI4qM. Brooks.                     naria mercenaria. Mar. Biol. 44:227-233.





































































                                                                                             42
 













                           Reprint 3


             Distribution and Sources of Organic
           Contaminants in Tidal River Sediments
                of the Washingtong D*C* Area

              Terry L. Wade,, David J. Vennsky, Eli
               Reinharz and Christian E. Schlekat

















                               43










               Distribution and Sources of Organic Contaminants in Tidal River Sediments of the Washington,
                                                        D.C. Area.





               Terry L. Wade

               Geochemical and Environmental Research Group, 833 Graham Road, Texas A&M University,

               College Station, TX 77845 (Tel: 409-690-OW5),



               David J. Velinsky

               Interstate Commission on the Potomac River Basin, Suite 300, 6110 Executive Blvd., Rockville, MD

               20852 (Tel: 301-984-1908),



               and



               Eli Reinharzl, Christian E. SchlekatF

               Maryland Department of the Environment, Toxics Registries and Analysis Program, Baltimore, MD

               21224.










               Present Addresses:

               'National Oceanic and Atmospheric Administration, Damage Assessment Group, Washington, D.C.

               20852 ( 'rel: 202-606-8000)

               'Science Application International Corporation, 165 Dean Knauss Drive, Narragansett, RI, 02882

               (Tel: 401-782-1900)




                                                            44




 I
 I                                                                                               Wade et al.
 I            Running head:
              T.L Wade et al.                               Organic contaminants in tidal river sediments
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I

                                                             10
 I









                                                                                                      Wade et al.





                                                              Abstract


                       Concentrations of aliphatic, aromatic and chlorinated hydrocarbons were determined from 45

               surface-sediment samples taken from the Tidal Basin, Washington Ship Channel, and the Anacostia

               and Potomac rivers in Washington, D.C. In conjunction with these samples, selected storm sewers

               and outfalls also were sampled to help elucidate general sources of contamination to the area.

                       All of the sediments contained detectable concentrations of aliphatic and aromatic

               hydrocarbons, DDE, DDD, DDT, PCBs, and chlordanes (oxy, cf, and 'y-chlordane and cis+ trans-

               nonachlor). Sedimentary concentrations of most contaminants were highest in the Anacostia River

               just downstream of the Washington Navy Yard, except for total chlordane which appeared to have

               ppstream sources in addition to storm and combined sewer runoff. This area has the highest

               concentration of storm and combined sewer outfalls in the river.   Potomac River stations exhibited

               lower concentrations than other stations. Total hydrocarbons (THQ, normalized to the fine grain

               fraction (clay+sUt, < 63 gm), ranged from 120 to 1900 ;Lg g7l fine grain. Ile hydrocarbons were

               dominated by the unresolved complex mixture (UCK with total polycyclic aromatic hydrocarbons

               (PAHs) concentrations ranging from 4 to 33 jug g" fine grain. Alkyl-substituted compounds (e.g., Cl

               to C4 methyl groups) of naphthalene, fluorene, phenanthrene+anthracene, and chrysene series

               dominated the polycyclic aromatic hydrocarbons (PAHs). Polycyclic aromatic hydrocarbons,

               saturated hydrocarbons, and the unresolved complex mixture (UCM) distributions reflect mixtures of

               combustion products (i.e. pyrogenic sources) and direct discharges of petroleum products, Total PCB

               concentrations ranged from 0.075 to 2.6 Ag g-I fine grain, with highest concentrations in the

               Anacostia River. Four to six Cl-substituted biphenyls were the most-prevalent PCBs. Variability in



                                                                 3




                                                                46









                                                                                                       Wade et al.


              the PCB distribution was observed in different sampling are-as, reflecting differing proportion of

              Arochlor inputs and degradation. The concentration of all contaminants was generally higher in

              sediments closer to imown sewer outfalls, with concentrations of THC, PAHs, and PCBs as high as

              6900, 620, and 20jug g-1 fine grain, respectively. Highest PCB concentrations were observed from

              two outfalls that drain into the Tidal Basin. Concentrations of organic contaminants from sewers

              draining to the Washington Ship Channel and Anacostia River had higher concentrations than

              sediments of the mid-channel or river. Sources of PCBs appear to be related to specific outfalls,

              while hydrocarbon inputs, especially PAHs, are diffuse, and may be related to street runoff.

                      Whereas most point souice contaminant inputs have been regulated, the importance of non-

              point source inputs must be assessed for their potential addition of contaminants to aquatic

              ecosystems. This study indicates that in large urban areas, non-point sources deliver substantial

              amounts of contaminants to ecosystems through storm and combined sewer systems, and control of

              these inputs must be addressed.





















                                                                 4




                                                                 47










                                                                                                  Wade et al.



                                                         Introduction

                     Currently existing National Oceanic and Atmospheric Administration (NOAA National

              status and Trends (NS&T), and Environmental Protection Agency (EPA) Environmental Monitoring

              and Assessment-Near Coastal (EMAP-NQ programs are concerned with determining current

              contaminant status of coastal areas of the United States. These programs are designed to provide an

              overview of the current status and long-term trends for relatively large geographical areas. However,

              there remains a need for specific studies to address questions of a more local concern. In order to

              reduce the input of contaminants to aquatic systems, such as the tidal system around Washington,

              D.C., regulations of point sources have been implemented. With the reduction of point source inputs,

              non-point sources such as storm water runoff now must be assessed as input sources of contaminants

              to aquatic systems.

                     The paper describes one portion of a study (see Velinsky et al. and Schlekat et al., this issue)

              to determine the distribution of sedimentary organic contaminants on a local scale in the Washington,

              D.C. area, employing validated analytical methods. Also, an important objective of this study was

              to establish the importance of combined and storm sewers as sources of contaminants to the sediments

              of the area. To accomplish this objective, selected storm and combined sewers were sampled, and

              organic contaminant distributions compared between sewer and river sediments.

                                              Sampling and Analytical Methods

                     The study area (Fig. 1) and sampling design has been described in detail in Velinsky et al.

              (1993). Sediment samples were obtained from the Tidal Basin (TB), Washington Ship Channel

              (WSC), Kingman Lake (KL), Potomac River (PR) and Anacostia River (AR) in June 1991 (Fig. 1).

              Sediments taken directly in front of storm and combined sewer outfalls were also collected from the



                                                               5




                                                              48









                                                                                                        Wade et al.


               Anacostia River, Washington Ship Channel, and Tidal Basin. In addition, selected sewers were

               sampled up-pipe Cl.e. entering the sewer line via street manholes) from the outfall in these locations

               (Velinsky et al. 1993). To accomplish this, D.C. Department of Public Works sewer maps were used

               to select specific sewer lines that drain into each area. Also, at one station in the Tidal Basin and

               Potomac and Anacostia rivers, three separate samples of three grabs each were taken within a radius

               of approximately 5 m to assess small-scale spatial variabflity.

                       In the Potomac River, four stations were sampled from the mouth of Rock Creek to the

               confluence of the Anacostia and Potomac Rivers and the Washington Ship Channel (Fig. 1). We did

               not obtain samples from sewers that drain into the Potomac River. In the Washington Ship Channel,

               five stations were sampled along the eastern side of the channel. Seven stations were sampled in the

               Anacostia River, all on the northwestern side of the river outside the center channel.

                       Sediments were collected with a stainless steel petite-Ponar grab sampler (0.023 mF) rinsed

               with acetone at the beginning of each day. ne upper 2 to 3 centimeters of sediment not in contact

               with the sides of the sampler were placed into a pre-cleaned pyrex-glass bowl. Ibis process was

               repeated three times. Sediments were mixed with a pre-cleaned stainless steel spoon until

               homogeneous in both texture and color, placed into pre-baked (420 OC for 12 hours) glass jars, and

               covered with pre-baked aluminum M. Between collections, the sampler was cleaned of any sediment

               and rinsed with ambient water at each station.

                       Grain size and total organic carbon determination are described in Velinsky et al. (1993).

               Sediments were extracted using the methods described in Wade et al. (1988). All internal standards

               (surrogates) were added to the samples prior to extraction and were used for quantification.

               Approximately 10 grams of freeze-dried sediment were soxhlet-extracted with methylene chloride.



                                                                  6



                                                                 49










                                                                                                    Wade et al.


              The solvent was concentrated to approximately 20 ml in a flat-bottomed flask equipped with a

              three-ball Snyder column condenser. Ile extract was then transferred to Kuderria-Danish tubes,

              which were heated in a water bath (6(rQ to concentrate the extract to a final volume of 2 ml.

              During concentration of the solvent, dichloromethane was exchanged for hexane.

                      The extracts were fractionated by alumina:silica gel (80-100 mesh) open column

              chromatography. Silica gel was activated at 17(rc fbr 12 hours and partially deactivated with 3%

              (y/w) distilled water. Twenty grams of silica gel were slurry packed in dichloromethane over 10

              grams of alumina. Alumina was activated at 400*C for four hours and partially deactivated with I %

              (v/w) distilled water. The dichloromethane was replaced with pentane by elution, and the extract was

              applied to the top of the column. ne extract was sequentially eluted from the column with 50 ml of

              pentane (aliphatic fraction) and 200 ml of 1: 1 pentane- dichloromethane (aromatic-pesticide fraction).

              The fractions were then concentrated to 1 ml using Kuderna-Danish tubes heated in a water bath at

              60-C. Each set of ten samples included a procedural blank and a spiked sample that were carried

              through the entire analytical procedure.

                      Aliphatic hydrocarbons were analyzed by gas chromatography in the splitless mode using a

              flame ionization detector (FM). A 30-m x 0.32-mm I.D. fused silica column with DB-5 bonded

              phase Q&W Scientific Inc. or equivalent) was used, with the chromatographic conditions providing

              baseline resolution of the n-C,.,/pristane and n- C@s/phytane peak pairs. Ile five calibration solutions

              were in the range of 1.25 to 50 ;Lg mr. Ile internal standard,s (surrogates) for the aliphatic

              hydrocarbon analysis were deuterated n-alkanes with 12, 20, 24 and 30 carbons, and were added at

              approximate 10 times the method detection limit.

                      Aromatic hydrocarbons were separated and quantified by gas chromatography-mass



                                                                7



                                                              50








                                                                                                       wade et al.


               spectrometry (GC-MS) aM890-GC and HP5970-MSD). The samples were injected in the splitless

               nwde onto a 0.25 mm x 30 ni (0.32 Am film thickness) DB-5 fused silica capillary column Q&W

               Scientific Inc. or equivalent) at an initial temperature of 6(rC and temperature programmed at 12*C

               min7l to 3WC and held at the final temperature fbr 6 minutes. Ite mass spectral data were acquired

               using selected ions for each of the PAH analytes. IMe GC-MS was calibrated by injection of a

               standard component mixture at five concentrations ranging from 0.01 ng/jul to I ng/;d. Sample

               component concentrations were calculated from the average response factor for each analyte. Analyte

               identifications were based on correct retention time of the quantitation ion (molecular ion) for the

               specific analyte and confirmed by the ratio of the confirmation ion.

                       A calibration check standard was run three times during the sample runs (beginning, middle

               and end), with no more than 6 hours between calibration checks. The calibration check was

               confirmed to maintain an average response factor within 10% for all analytes, with no one analyte

               greater than 25% of the known concentration. With each set of samples, a laboratory reference

               sample (oil solution) was analyzed to confirm GC-MS system performance. The internal standards

               (surrogates) for the PAH analysis were ds-naphthalene, dIO-acenaphthene, d,.-phemthrene, d,27

               chrysene, and d,2-perylene, and were added at concentrations similar to that expected for the analytes

               of interest.

                      The pesticides and PCBs were separated by gas chroma graphy in the splidess mode using an

               electron capture detector (ECD). A 30-m. x 0.32-mm I.D. fused silica column with DB-5 bonded

               phase (J&W Scientific or equivalent) was used. Four calibration solutions containing the pesticides

               and the PCBs were used to generate a non-linear line fit with calibration standards in the range of 5 to

               200 ng m171. 7be internal standards (surrogates) for pesticide and PCB analysis, added prior to



                                                                  8



                                                                 51










                                                                                                Wade et al.



            extraction, were DBOFB (dibromooctafluorobiphenyl), PCB-103, and PCB-198. Ile

            chromatographic conditions for the pesticide-PCB analysis were 100*C for I min, then 5*C Milo to

            140*C, hold for I min, then 1.5C min7' to 2500C, hold for I min, and then 10*C min7l to 300*C and
            a final hold of 5 min.                Results and Discussions

            Sediment= hydrocarbo

                    Sedimentary hydrocarbons concentrations were variable throughout the study area, probably

            due to transport processes, biological and chemical differences between individual compounds (i.e.,

            water solubility, volatility, and weathering and microbial degradation rates), and the differences in

            input sources of these compounds. Total hydrocarbons concentrations (THQ in the Potomac River

            sediments ranged from 110 to 167 jig g7' (Table 1). The highest concentration was at station PR-1

            which is located near the mouth of Rock Creek (Fig. 1). In the Potomac River, the UCM was the

            dominant THC component, averaging 84 ï¿½ 0.04% of the THC. The polycyclic aromatic

            hydrocarbon (PAHs) concentration are of particular interest because they have been shown to have a

            significant effect on the mortality, abundance, and diversity of benthic organisms (Landrum et al.

            1991; Kennish 1992). Sediment concentrations were highest at PR-1 (29 ;Lg S71 ) compared to other

            river, basin, or channel sediments (excluding outfall or sewer sediment). Stations PR-2, PR-3, and

            PR-4(a,b,c) had uniform PAH concentrations, averaging 3.6 ï¿½ 0.4 Ag g7l (n=5, station PR-4 was

            sampled in triplicate). The higher concentrations of both PAHs and the UCM indicate a greater

            amount of anthropogenic hydrocarbons at PR-1, most likely due to runoff from Rock Creek, which

            drains through the more residential center of Washington, D.C.

                   In the Tidal Basin, THC and PAH ranged from 169 to 613 Ag g' and from 0.4 to 11.6jug g7l



                                                             9



                                                            52










                                                                                                Wade et al.



              respectively. The higher concentrations of PAH at TB-1 and TB-1.5 were associated with large

            storm sewer and vehicular traffic on Kutz Bridge near TB-1.5. THC concentrations ranged from 120

            to 467 ;Lg g' in Washington Ship Channel (WSC) sediments. The highest sediment concentrations

            were at stations WSC-I, WSC-2, and WSC-3, located at the upper end of the channel. As in the

            other areas, THCs were dominated by the UCM (UCM/THC a 95%), suggesting that the THCs

            were composed mainly of weathered petroleum products (Farrington 1980). Sediment PAH

            concentrations were fairly uniform throughout the channel with an overall average of 7.0 ï¿½ 1.0 ug g-I

            (n = 5).

                   To assess geographical trends of hydrocarbons in the Anacostia River, concentrations of

            organic compounds are presented along a transect from KL-5, at the entrance to Kingman Lake in the

            AR, to PR-4, which is located at the confluence of the Anacostia and Potomac rivers (Fig. 1; Table

            1). 7bis transect includes WSC-6, located at the confluence of the AR and the WSC. Along the

            river, at AR4, which is located just upstream of the South Capitol Street Bridge (Fig. 2),

            concentrations of THC and PAHs reached a maximum of 1600,ug r' and 28 ;Lg g-' , respectively.

            From AR4 to PR4, a substantial decrease occurred in the concentrations of both THC and PAHs.

            At the most downstream station (PR4A), concentrations of THC and PAHs, 126 jug g' and 4.4 ;tg g-

            I , respectively, were some of the lowest measured in this study. Similar trends also were fbund for

            trace metals (e.g., Pb and Cd; Velinsky et al. 1993), indicating a substantial local source of sediment

            contamination near the Washington Navy Yard and the South Capital Street Bridge (Fig. 1).

                   Several stations were sampled and analyzed in triplicate to assess the small-scale spatial

            variability. Triplicate samples of three grabs each were taken within approximately 5 m of each

            other. Tbe percent relative standard deviation (%RSD; ï¿½ SD/mean X 100) for THC, SHC, and the



                                                            10



                                                           53









                                                                                                 Wade et al.


            UCM was all generally < ï¿½ 15 % fbr the Potomac River (PR-4) and the Anacostia River (AR-5). In

            the Tidal Basin (TB-5), total PAH concentrations agreed to within ï¿½ 5% RSD (n-3); however,

            concentrations of THC, SHC and UCM had higher concentrations for sample TB-5b. It is unclear

            why the THC, SHC, and UCM were elevated in TB-5b. Trace metals, TOC, and grain size data

            (Velinsky et al. 1993) were not elevated for TB-5b compared to TB-5a,c. Due to the close agreement

            between TB-5a and TB-5c for both the SHC and UCM, the data for TB-5b is not included in the

            average and fin-ther discussions. These results, along with the TOC and grain size data (Velinsky et

            al. 1993), indicate that the variability of the "local" area is smaller than some of the geographic trends

            between the various study areas.

                    One of the objectives of this study was to evaluate sources of organic contaminants to river

            sediments in the Washington, D.C. area. Sediment samples were collected at the outfalls of selected

            storm and combined sewers (1Ds with the prefix 0; Table 1) in the Tidal Basin, Washington Ship

            Channel, and Anacostia River. Sediments also were taken from combined and storm sewers (IDs

            with the prefix S; Table 1) that drain into these areas. Sediment hydrocarbons concentrations for

            rivers, outfalls, and sewers were divided by the fraction of fine grain sediment (< 63 jLm) in each

            sample (Velinsky et al. 1993).

                    Total hydrocarbons and total PAHs concentrations from outfall and sewer sediments from the

            Tidal Basin and Washington Ship Channel were substantially elevated compared to sediments collected

            away from the outfalls (Fig. 3). The PAH concentrations in outfall. samples ranged from 10 to 620

            Ag 9*1 fine grain, with highest concentrations from one site in the WSC. These concentrations were

            substantially higher than those found in mid-basin or channel sediments. Ibis suggests that a

            dominant source of hydrocarbons to the basin and channel is runoff from numerous streets and







                                                            54









                                                                                                  Wade et al.



             highways in the area via the storm sewer system (there are no combined sewers in these areas). The

             distribution of THC and PAHs at the outfalls indicated no specific storm sewer as the predominate

             source of hydrocarbons to these areas, as opposed to the trace metal dam, notably Pb, which did

             indicate specific outfalls (e.g., OTB-3&4, OAR-3) as major sources (Velinsky et al. 1993). It

             appears that the input of hydrocarbons to the basin is diffuse, and may be related to the overall

             vehicular traffic in the surrounding area.

                    While the gradients between outfall and sediment samples indicate the source of hydrocarbons

             is from street runoff, the numerous marinas that border the eastern side of the WSC could also

             contribute hydrocarbons to channel sediments. The input of hydrocarbons would be related to boating

             activities, fuel spills, and engine exhaust, as well as from creosote-treated pilings used for the

             construction of these marinas (Vouldrias and Smith 1986; McGee et al 1993).

                    In the Anacostia River (AR), five outfall and four sewer samples were obtained, allowing a

             more comprehensive analysis of the sediment hydrocarbon distribution (Fig. 4). Of the four sewers

             sampled, two are storm sewers (SAR-5 and SAR-6), and two are combined sewers (SAR-2 and SAR-

             3); all were sampled as close to the river as possible. In most cases, the concenmations of THCs and
             PAHs were highest in the sewer samples co'mpared to either the outfall or sediment samples (Fig. 4).

             A comparison was made between hydrocarbon concentrations of three groups of river, outfall, and

             sewer samples within the AR (Fig. 4). The material collected in the sewer is a possible source of

             hydrocarbons at the outfall, and thus would most directly affect the sediments in the river at the

             station closest to the outfafl. Total hydrocarbons and PAH concentrations were higher from all sewer

             samples compared to their respective river samples (Fig. 4). This trend is particularly evident in the

             series located near the Washington Navy Yard (i.e., series AR4, OAR-3, and SAR-5).



                                                             12



                                                             55









                                                                                                 Wade et al.


             Concentrations of THC decreased from 4500 at SAR-5 to approximately 2000,ug g*' fine grain at

             both OAR-3 and AR4 (Fig. 4), while PAH concentrations decreased by a factor of 5 between SAR-5

             and AR4. Ile decrease in THC and PAH concentrations in river sediments compared to sewer

             samples may be due to both degradation and dilution with sediments having lower hydrocarbon

             concentrations.

                    These results indicate that a major source of hydrocarbon contamination to the sediments of

             the Anacostia River may be street runoff through the combined and storm sewer system of the area.

             Gavens et al. (1982) showed that in an urban catchment basin near London (G.B.), up to a 3 fold

             increase in sedimentary PAHs occurred due to urban runoff. Street dust, including material from

             tires, road asphalt, and crankcase oils, are possible sources of hydrocarbons in this runoff. Wakeham

             et al. (1980) compared the PAH content of various lake sediments in Switzerland to various urban

             source materials, and concluded that street dust (e.g., asphalt and tire, and crankcase drippings) was a

             major source of hydrocarbons to the sediments. Other sources, such as atmospheric deposition and

             direct oil spills to the river, may be important, but the extreme concentration gradient between river,

             outfall, and sewer sediment samples suggests that urban runoff is a major source. Samples taken

             around station AR4, near the Washington Navy Yard, indicate that this may be the most severely

             impacted area in the Anacostia River, and may be the most affected by runoff from the urban area of

             Washington, D.C.



             Molecular DutHbution of H)*ocarbons

                    Total sedimentary hydrocarbons consist of saturated hydrocarbons (SHC), polycyclic aromatic

             hydrocarbons (PAH), and the unresolved complex mixture (UCM). Ile UCM contains co-eluting



                                                             13



                                                            56









                                                                                                        Wade et al.



              compounds that are not resolved by current capillary gas chromatographic techniques, and are thought

              to be mainly alicyclic: hydrocarbons. Saturated hydrocarbons are the sum of normal alkanes from a-

              C1. to n-Cu including the isoprenoids pristane and phytane, and PAHs are the sum of 44 individual or

              groups of aromatic hydrocarbons. While PAHs are potentially more harmful to aquatic organisms

              than SHC or UCM, the molecular distribution and abundance of the UCM, SHC, and PAH provides

              information concerning the sources and transformations of hydrocarbons (Farrington 1980; Hites et

              al. 1980; Wakeharn et al. 1980; Boehm and Farrington 1984; Boehm 1984; Pruell and Quinn 1985).

                      The UCM accounted for the majority of THC in sediments, outfall and sewer samples, with

              minor contributions of both SHCs and PAHs. For most sediments the UCM accounted for a 95% of


              the THC with little variation between sites. The abundance of the UCM at all collection sites indicates

              that weathered petroleum products are a major component of hydrocarbon contamination in this area.

              In the Potomac River however, the UCM comprised :9 90% of the SHC, indicating less of a

              contribution of weathered petroleum hydrocarbons. The source of thd.UCM in all areas is most
              likely runoff from streets and highways, although direct discharge of oil (i.e., small spills) cannot be

              ruled out (Eganhouse and Kaplan 1981a; 1981b; Hoffman et al. 1983; 1984; Brown et al. 1985).

              While the concentration and presence of the UCM indicates a weathered-petroleum hydrocarbon

              source, the molecular distribution of PAHs can give an indication of the relative contribution of

              hydrocarbons from petroleum versus combustion sources.

                      Low versus high molecular weight PAHs (i.e., LMW and HMW PAHs) are indicative of the

              input sources of hydrocarbons (Farrington 1980; Boehm and Farrington 1984). Low molecular

              weight PAHs are defined as 2 to 3 benzene ring compounds, including naphthalenes, anthracenes,

              phenanthrenes, and dibenzothiophenes. High molecular weight PAHs, with 4 to 5 benzene rings,



                                                                  14



                                                                 57










                                                                                               Wade et al.



            include compounds such as fluoranthenes, chrysenes, benzo[a]pyrene and dibenz[ah]anthracene. A

            predominance of LMW over HMW PAHs indicates an oil source of hydrocarbons (Farrington 1980;

            Boehm and Farrington 1984). Due to weathering and degradation processes, with time LMW PARs

            would decrease in abundance relative to HMW PAHs. Also, the combustion of petroleum yields

            PAHs with more HMW compounds.

                   In most sediments from this study, LMW PAH accounted for approximately 35% of the total

            PAH (Velinsky et al 1992). In the Anacostia River, at stations AR-4 and SAR-5 however, LMW

            PAH accounted for 60% and 90% of the total PAHs, respectively  . Storm sewer SAR-5 empties into

            the river near station AR-4 at the outfall OAR-3. Low molecular weight hydrocarbons accounted fbr

            only 40% of the total PAHs; at station OAR-3. These results indicate a distinct source of petroleum-

            derived hydrocarbons (e.g., oil) to the area just south of the Washington Navy Yard near the South

            Capitol Street Bridge.

                   Substantial quantities of unsubstituted PAHs were found in all river, outfall, and sewer

            sediments analyzed. Major compounds include alkylated phenanthrene-andiracene, fluoranthene,

            pyrene, benz(a]anthracene, and benzopyrenes. Concentrations of alkylated fluoranthene-pyrene

            ranged from 0.56 to 5.3 ILg g7, benz[alanthracene from 0.11 to 0.93 #g g-, and benzo[a+e]pyrenes

            from 0.23 to 1.7 ;Lg g7' for all river sediment samples. Higher concentrations were found in outfall

            and sewer samples (Velinsicy et al. 1992). The abundance of individual HMW PAH compounds in

            most samples suggests that combustion products are also a source of the PAHs to the sediments of

            this area (Youngblood and Blumer 1975).

                   The variations in individual PAH compounds reflect a mixture of combustion products (i.e.,

            pyrogenic sources) and direct discharge of petroleum products. These distributions are similar to



                                                           15









                                                                                                 Wade et al.



             other urban areas (Farrington and Quinn 1973; Wakeham et al. 1980; Hoffman et al. 1983; 1984;

             Eganhouse and Kaplan 1981b; Brown et al. 1985). Specific areas that indicate increased combustion

             inputs of hydrocarbons include station PR-I near Rock Creek, stations WSC-1, 2, and 3, and the area

             around AR-4 (Velinsky et al. 1992). Only in the Anacostia River, near the Washington Navy Yard

             (i.e., AR-4), are direct inputs of petroleum a more significant component of the sediments.



             Chlorinated Hydrocarbons

                    The concentration of a selected suite of chlorinated hydrocarbons were determined as part of

             this study. Sediment concentrations of total chlordane (sum of oxy-, -f-, and a-chlordane and

             cis +trans-nonachlor), total DDT (sum of 2,4'+ 4,4' forms of DDT, DDD, and DDE), and total

             PCBs ranged from 5 to 150, 7 to 160, and 70 to 2200 ng gl, respectively, for river, basin or channel

             sediments (Table 2). The highest sedimentary total chlordane levels from the Potomac River (43 ng

             91 were near Rock Creek at station PR-I, with lower concentrations downstream. This site also
             exhibited high concentrations 'of total DDT and PCBs compared to the other sampling sites in the

             Potomac River. The highest concentrations of total chlordane, total DDT, and PCBs in the Tidal

             Basin were found at stations TB-I and TB-1.5. These sites are located near the large storm sewer

             oudWI that drains along Constitution Avenue and the Mall of the Smithsonian Institution. The

             sediment concentrations of total DDT at these stations, 160 and 170 ng g', were some of the highest

             measured in this study.' Concentrations of total chlordane, DDT, and PCBs in the Washington Ship

             Channel were intermediate compared to the other study areas, with no distinct geographical

             distribution (Table 2).

                    Higher concentrations of total chlordane were determined in the Kingman Lake area (e.g.,



                                                             16



                                                              59









                                                                                                  Wade et al.


             maximum at KL4 of 150 ng 91 and upper Anacostia River (Fig. 2) compared to farther

             downstreauL Concentrations decreased to approximately 27 ng g*1 at PR-4A, located just south of

             Hains Point in the Potomac River. This distribution, suggests a possible input source within or

             upstream of the Kingman Lake area. In contrast, concentrations of both total DDT, PCBs, and

             hydrocarbons reached maximum levels farther downstream in the Anacostia River at station AR-4.

             Sediment concentrations of total DDT and PCBs were 124 and 2200 ng fl, respectively, at AR-4.

             Numerous storm and combined sewers drain into this area, and these levels are probably a result of

             these sources (see below). This location also has elevated concentrations of trace metals (Velinsky et

             al. 1993), THCs, and PAHs. Below the South Capital Street Bridge and the Washington Navy Yard

             (i.e., AR-4), concentrations of all sediment contaminants decreased to baseline levels. The distribution

             of total chlordane indicates different input sources to the Anacostia River compared with other organic

             and inorganic contaminants.

                    Concentr-ations of total chlordane, DDT, and PCBs in outfalls of the Tidal Basin and

             Washington Ship Channel reached levels of 260, 4200 and 18000 ng g-I fine grain respectively, and

             are substantially higher than those determined in the mid- basin or channel sediments (Fig. 5).

             Outfalls OTB-3 and OTB-4 had extremely elevated concentrations in the Tidal Basin. The sewer

             (STB-2), taken on two separate occasions, had concentrations of total chlordane, DDT, and PCBs

             only slightly elevated compared to basin sediments. This sewer is a sanitary sewer running along

             15th St., S.W., servicing the Bureau of Engraving and Printing and the Department of Agriculture.

             The material in this sewer line would most likely not impact the Tidal Basin, and would eventually be

             sent to Blue Plains Wastewater Treatment facility fbr treatment and disposal. Total chlordane, DDT,

             and PCB outfall sediment concentrations in the Washington Ship Channel were is high as, WO, 2100,



                                                             17



                                                             60








                                                                                                  Wade et al.


            and 5200 ng g"' fine grain, respectively. Highest total chlordane and DDT concentrations were fbund

            at OWSC-3, while total PCB concentrations were highest at all three upstream outfWls (i.e., OWSC-2

            to OWSC-Rl; Fig. 5).

                    A substantial concentration gradient between sewers, outfalls and sediments of the Anacosda

            River was observed for total chlordane, DDT, and PCBs (Fig. 6). Concentrations in this series were

            as high as 660, 400, and 6400 ng g` fine grain for total chlordane, DDT, and PCBs, respectively.

            As with non-chlorinated hydrocarbons, a large decrease in concentrations was found between the

            sewer, outfall, and sediments near station AR-4 (i.e., SAR-5 > > OAR-3 > > AR-4) (Fig. 6).

            Similar decreases were observed in varying degrees for the other river, outfall, and sewer sediment

            series within Anacostia River (Fig. 6). These data indicate that street and land runoff, as well as

            possible combined sewer overflows, are sources of total chlordane, DDT,and PCBs to the sediments

            of the Anacostia River.


                    Persistence of PCBs in aquatic sediments is due to their slow rate of degradation and

            vaporization, low water solubility, and partitioning to particles and organic carbon (Kennish 1992).

            Bacteria degrade PCBs, with the rate dependent on the position and degree of chlorination of the

            biphenyl ring (Reutergardh 1980; Abramowicz et al. 1993; Rhee et al. 1993). Interestingly, the PCB

            congener distribution patterns are not similar among sediments of this study area (Velinsky et al.

            1992). In the Tidal Basin and Potomac River, congeners with six and seven chlorine substitutions

            dominated, while congeners with four to six chlorines were the major component of the PCBs of

            Washington Ship Channel and Anacostia River sediments. These results suggest two distinct sources

            of PCB contamination in this study area. However, the selective degradation of PCBs with lower

            chlorine contents can not be ruled out as the cause of the different distributions (Reutergardh 1980



                                                             Is



                                                             61










                                                                                                 Wade et al.



            and others).

                    Sources of the pesticide DDT measured in the present study are elusive. Banned in 1972, and

            with an approximate environmental half-life of 10 to 20 years (NOAA 1989; Woodwell et al. 1971;

            Sericano et al. 1990), its detection, along with its breakdown products (i.e., DDE+DDD) in

            sediments, is to be expected. Generally, (2,4'+ 4,4) DDE accounted for the greatest abundance of

            the three forms of DDT, with approximately 70 to 90% of the total DDT in sediments as the sum of

            DDE and DDD (2,4' + 4,4') forms. This distribution indicates an active degradation of DDT in the

            sediments and/or inputs of already degraded DDT to the area. DDT can be degraded to DDD by

            micro-organisms and phytoplaakton or to DDE via dehydrochlorination produced by biotic or abiotic

            decomposition reactions (Fries 1972; Addison 1976; Gerlach 1981).

                    In all outfalls and sewers sampled in the Anacostia River, along with specific ones in the

            Tidal Basin and Washington Ship Channel, (2,4'+ 4,4') DDT accounted for approximately 40 to

            60% of the total DDT, and with the extreme concentrations measured at these sites, detrimental

            biological effects could occur. Ile large sedimentary concentrations of (2,4+ 4,4') DDT at outfalls.

            and in sewers is interesting given the apparent lack of any definitive recent inputs. It might be

            expected that DDT would have been flushed through the sewer system 20 years after its ban. Schmitt

            et al. (1985) suggested that DDT may be a contaminant in other pesticide mixtures; however, the

            study of Schmitt et al. (1985) was conducted in cotton farming areas in the southwest U.S. and may

            not be applicable to the District. Alternatively, it is possible that re-exposed soils from construction

            projects could introduce DDT to the environment.

                   Technical chlordane is a pesticide, used fbr termites and cutworms, that is a mixture of

            approximately 140 compounds. Due to its known health effects, sale of technical chlordane was



                                                             19



                                                             62









                                                                                                  Wade et 9.



            halted in 1988 after step-wise control of its uses. Alpha (ct)- and gamma (,y)-chlordane are the two

            main components of technical chlordane. The different fbrms and breakdown products of technical

            chlordane were fbund at all locations with the exception of oxy-chlordane, which was found in only

            nine samples. Generally, oxy-chlordane was found in detectable concena-ations in specific outfall and

            sewer sediment samples in the Tidal Basin, Washington Ship Channel, and Anacostia River, and

            accounted for 3 to 14% (n=9) of the total chlordane. Oxy-chlordane is a breakdown product of

            chlordane and is thought to be more toxic than the other forms of chlordane. Throughout the DC

            area, y-chlordane was the major chlordane found in this study area with lesser amounts of a-

            chlordane and cis+trans-nonachlor (Velinsky et al. 1992).



            Co=arisons to other Studies

                    Comparisons of the data from this study to other studies is not straightforward. The variable

            nature of the sediments (i.e., grain size, organic carbon, etc.) are often ignored or can not be

            accounted fbr from other studies that did not report bulk sediment characteristics. Also, the selection

            of specific studies can bias the interpretation between data sets. For this reason, only data from the

            Chesapeake Bay and Delaware Bay will be utilized to give a regional assessment of sediment

            contamination.

                   Concentrations of selected organics from the mid-Adantic region are compared in Table 3. In

            the present study, station AR-4 in the Anacostia River exhibited the highest concentrations, while the

            Potomac River sediments have some of the lower concena-ations (excluding outfall or sewer sediment

            samples). Ile concentration of total PCBs in the Baltimore Harbor and Schuykill River (Philadelphia,

            PA.) are much higher than the Washington, D.C. area. For all groups of organics, concentrations



                                                              20



                                                             63










                                                                                                   Wade et al.



             measured in this study are higher than those from the mainstem Chesapeake Bay, again reflecting the

             effect of urban environments on adjacent sediments. Compared to other studies, the sediments of the

             tidal freshwater Washington, D.C., area are moderately to highly contaminated, with the most severely

             impacted area located in the Anacostia River near station AR-4.



                                                  Summary and Conclusions

                     7be geographic and spatial trends for sedimentary organic reveal specific areas of concern

             within the tidal freshwater section of the upper Potomac estuary. 17hese locations are show increased

             sediment concentrations of organic contaminants relative to adjacent locations, and within the entire

             study area of the Potomac and Anacostia rivers. In many cases, both trace metals (see Velinsky et al.

             1993) and organics exhibit the same geographic trend. Substantial concentrations of organics such as

             hydrocarbons (e.g., PAHs), PCBs, and DDTs were observed in many areas, such as near the

             Washington Navy Yard (AR-4), near the mouth of Rock Creek in the Potomac River (PR-1), and

             upper Washington Ship Channel (WSC-I to WSC-3). Concentration gradients between sewer, outfall,

             and river sediment samples strongly suggest that urban runoff is a major non-point source of these

             contaminants to the sediments. For certain constituents like THC and PAH, the outfall sediment

             concentrations indicate a diffuse distribution related to the ubiquitous nature of their sources (I.e.,

             fossil fuel combustion, crankcase oils etc.), while other contaminants, such as PCBs, have

             distributions that suggest more of a source input through specific outfalls. 7be distribution of total

             chlordane, which was markedly different than other organic contaminants, suggests inputs upstream of

             the Washington, D.C. area. Also, the analyses of a limited number of benthic: clams (Corpicula sp.)

             from selected sites indicates that the contaminants found in the sediments are bioavailable (Velinsky



                                                              21



                                                              64










                                                                                                   Wade et al.



             et.al. 1992) and may cause a biological response (Schlekat et al. 1993).

                     Large urban areas are non-point sources and deliver substantial amounts of organic

             contaminants to ecosystems through their sewer system runoff. With the decrease in point source

             contaminant inputs due to effective regulation, non-point source inputs must be assessed for their

             potential addition of contaminants to aquatic systems. Also, the toxicity of these sediments must be

             considered when making management decisions that might release or redistribute these contaminants.

             Organic contaminant concentrations found in this urban area are moderate to high, and may exert

             adverse effects on local ecosystem (see Schlekat et al. 1"3).
































                                                              22



                                                              65










                                                                                               Wade et al.





                                                    Acknowledgments

                    We thank Carlton Haywood (ICPRB), Beth McGee (MDE), and Tom Jackson (GERG) for

            technical assistance and help with the field sampling. Bob Cuthberson of the Marylod Geological

            Survey provided the vessel and support during sampling. 717his project was funded by the Department

            of Consumer and Regulatory Affairs, Water Hygiene Branch, of the District of Columbia and

            additional support was provided by the Interstate Commission on the Potomac River Basin. C.

            Dalpra provided helpful editorial comments. T'he opinions expressed are those of the authors and do

            not necessarUy represent the opinions or polices of ICPRB and MDE.






























                                                           23









                                                                                               Wade et al.



                                                     ILiterature Cited

            Abramowicz, D.A., MJ. Brennan, H.M. Van Dom and E.L. Gallagher. 1993. Factors influencing

              the rate of polychlorinated biphenyl dechlorination in Hudson River sediments. EnviroMental

              Science Tgghnolo , 27: 1125-113 1.



            Addison, R.F. 1976. Effects of Pollutants on Aquatic Organisms, University Press, Cambridge.



            Boehm, P.D. 1984. Aspects of the saturated hydrocarbon geochemistry of recent sediments in the

              Georges Bank region. Organic Geochemis , 7: 11-23.



            Boehm, P.D. and J.W. Farrington. 1984. Aspects of the aromatic hydrocarbon geochemistry of

              recent sediments in the Georges Bank region. Environmental Sciencï¿½ and Technology, 19: 840-945.



            Brown, R.C., R.H. Pierce, and S.A. Rice. 1985. Hydrocarbons contaminntion in sediments from

              urban stormwater runoff. Marine Pollution Bullet , 16: 236-240.



            Burlingame, Al et al., 1972. The molecular nature and complexity of trace organic constituents in

              Southern CA municipal wastewater effluents. IL Identification and analysis of organic pollutants in

              water. Ann Arbor Science Pub., Ann Arbor, MI.



            Dearth, M.A. and R.A. Hites. 1991. Complete analysis of technical chlordane using negative

              ionization mass spectrometry. Environmental Science and Technol2gy, 25: 245-254.



                                                           24



                                                           67










                                                                                                 Wade et al.



             Eganhouse, R.P. and I.R. Kaplan. 1981a. Extractable organic matter in urban stormwater runoff. 1.

               Transport dynamics and mass emission rates. Envirorunental Science and Technology, IS: 310-315.



             Eganhouse, R.P. and I.R. Kaplan. 1981b. Extractable organic matt in urban stormwater runoff. 2.

               Molecular characterization. Environmental Science and Technolon, 15: 315-326.



             Farrington, J.W. 1980. An overview of the biogeochemistry of fossil fuel hydrocarbons in the marine

               environment. IM L. Petrakis and F.T. Weiss (eds.) Petroleum in the Marine Environment,

               Advances- in Chemista Series 18 , American Chemical Society, Washington, D.C., 1-22 p.



             Fries, G.F. 1972. Degradation of chlorinated hydrocarbons under anaerobic conditions. IQ: R.F.

               Gould (ad.) Fate of Organic Pesticides in the Aguatic Environment. Advances in Chemis    , Series

               M, American Chemical Society, Washington, D.C., 256-270 p.



             Gavens, A., D.M. Revitt, and J.B. Ellis. 1982. Hydrocarbons accumulation in freshwater sediments
               of an urban catchment. Hydrobiologi !, 91: 285-292.


             Gerlach, S.A. 198 1. Marine Pollution: Diagenesis and '17herapy. Springer-Verlag, New York, 218 p.



             Hites, R.A., R.E. Laflamme, I.G. Windsor, J.W. Farrington, and W.G. Deuser 1980. Polycyclic

               aromatic hydrocarbons in an anoxic sediment core from the Pettaquamscutt River (Rhode Island,

               USA). Geochimica Cosmochimica A        4: V3-V8.



                                                             25


                                                             68










                                                                                               Wade et al.


             Hoffman, E.J., G.L. Mills, J.S. Latimer, and J.G. Quinn. 1983. Annual input of petroleum

              hydrocarbons to the coastal environment via urban runoff. Canadian Journal of Fisheries

              Aguatic Science 40: 41-53.



             Hoffman, E.J., G.L. Mills, J.S. Latimer, and I.G. Quinn. 1984. Urban runoff as a source

              of PAHs to coastal waters. Environmental Science and Technology, 18: 580-587.



             Interstate Commission on the Potomac River Basin (ICPRB) 1988. Anacostia: Ile Other River.

              ICPRB Publication 88-1, January 1988, Rockville, MD.



             Interstate Commi ion on the Potomac River Basin (ICPRB) 1990. Sediment Survey of Priority

              Pollutants in the District of Columbia Waters. lCPRB Publication 90-2, March 1990, Rockville,

              MD.



             Kennish, M.J. 1992. Ecology of Estuaries: Anthro22genic Effects, CRC Press, Boca Raton, FL,

              494 p.



             Landrum, P.F., BT Eadie, and W.R. Faust. 1991. Toxicokinetics and toxicity of a mixture of

              sediment-associated polycyclic aromatic hydrocarbons to the amphipod Disporeia sp. Environmental

              Toxicoloa Ed Chemi=, 10: 35-46.







                                                           26


                                                           EQ









                                                                                             Wade et al.


            Lyman, WI., A.E. Glazer, J.H. Ong, and S.F. Coons. 1987. An Overview of Sediment Quality in

              the United States, Final Report. R=rt.# EPA-905/9-88-002, U.S. Environmental Protection

              Agency, Office of Water Regulations and Standards, Washington, D.C.



            McGee, B.], C.E. Schelkat, and T.L. Wade. 1993. Sources and distribution of TBT in a freshwater

              marina. Environmental Toxicology and ChemiW, (submitted).



            National Oceanic and Atmospheric Administration. 1989. A summary of data on tissue contamination

              from the first three years (1986-1988) of the Mussel Watch project. NOAA Technical Memorandum

              NOS OMA 49, Rockville, MD.



            National Oceanic and Atmospheric Administration. 1991. National Status and Trends Program.

              Second Summary of Data on Chemical Contaminants in Sediments from the National Status and

              Trends Program. NOAA Technical Memorandum NOS OMA 59, National Ocean Service,

              Rockville, MD.



            Pruell, RJ. and J.G. Quinn. 1985. Geochemistry of organic contaminants in Narragansett Bay

              sediments. Estuarine Coastal and Shelf Scienc , 21: 295-312.



            Reutergardh, L. 1980. Chlorinated hydrocarbons in estuaries. In: E. Olausson and 1. Cato (eds.)

              Chemiga Ed Biog2whemista of Estuari       Chapter 11. Wiley and Sons, N.Y., 349 p.





                                                          27



                                                          70










                                                                                                     Wade et al.


               Rhee, G., R.C. Sokol, C.M. Bethoney, and B. Bush. 1993. Dechlorination of polychlorinated

                 biphenyls by Hudson River sediment organisms: Specificity to the chlorination pattern of congeners.

                 ]Environmental Science Technology, 27: 1190-1192.



               Sawhney, B.L., C.R. Frink, and W. Glowa. 1991. PCBs in the Housatonic River: Determination and

                 distributions. Journal of Environmental Qualily, 10: 444 448.



               Schlekat, C.E., B.L. McGee, D.M. Boward, D.J. Velinsky, and T.L. Wade 1993. Biological effects

                 associated with sediment contamination in the Potomac and Anacostia rivers in the Washington,

                 D.C. area. Estuaries (Submitted).



               Schmitt, CJ., J.L. Zajicek, and M.A. Ribick 1985. National Pesticide Monitoring Program; Residues of

                 organochlorine chemicals in freshwater fish, 1980-1981. Environmental Contamination and Toxicolg

                 14: 225-260.




               Velinsky, DJ., C.H. Haywood, T.L. Wade, and E. Reinharz. 1992. Sediment Contamination Studies of

                 the Potomac and Anacostia Rivers around the District of Columbia. ICPRB Publication 92-2, Interstate

                 Commission on the Potomac River Basin, Rockville, MD.



               Velinsky, DI., T.L. Wade, C.E. Schlekat, B.M. McGee, and B.J. Presley 1993. Distribution and Sources

                 of ft= metals to tidal river sediments of Washington, D.C. Estuari (submitted).





                                                                   28



                                                                71










                                                                                                Wade et aL


              Voudrias, E.A. and C.L. Smith. 1986.'Hydrocarbons pollution from marinas in estuarine sediments.

                Estuarine Coastal and Shelf Scienc , 22: 271-284.



              Wade, T.L., E.L. Atlas, J.M. Brooks, M.C. Kennicutt 11, R.G. Fox, J. Sericano, B. Garcia-Romero, and

                D. DeFreitas. 1988. NOAA Gulf of Mexico Status and Trends Program: Trace organic contaminant

                distribution in sediments and oysters. Estuaries, 11: 171-179.



              Wakeham, S.G., C. Schaffner and W. Giger. 1980. PAHs in recent lake sediments 1. Compounds having

                anthropogenic origins. Geochimica Cosmochimica Act , 44: 403-413.



              Woodwell, G.M., P.P. Craig, and A.J. Horton 1971. DDT in the biosphere: Where does it go.. Scienc ,

                174: 1101-1107.




              Youngblood, W.W. and M. Blumer. 1975. Polycyclic aromatic hydrocarbons in the environment:

                homologous series in soUs and recent marine sediments. Geochimica Cosmochimica A , 39: 1303-1314.


















                                                               29


                                                            72











                                                                                                                Wade et al.





                 Table 1. Sedimentary concentrations of hydrocarbons from the various study areas*.




                  Sta. M.                      PAH               SHC              UCM              THC


                  King= Lake


                  KL-I                         16.1              17.7              911              944


                  KL-2                         15.3              14.9             1000             1030


                  KL-3                         14.2              15.2             2090             2120


                  KL-4                         10.3              15.9             1270             1300


                  KL-5                           9.8             27.9              952              890


                  Awcosda River


                  AR-I                         14.4              12.7              902              929


                  AR-2                         15.1              22.1             1370             1410


                  AR-3                         13.2              12.1              856              981


                  AR-4                         28.3              31.0             1540             1590


                  AR-5A                          9.6             10.7              794              804


                  AR-6                           5.7               6.2             350              362


                  OAR-I                        23.7              26.2             1460             1510


                  OAR-2                        28.6              21.6              876              926




                                                                           30


                                                                      73











                                                                                                               Wade et al.




                  ShL ID.                     PAH               SHC             ucm               THC



                  OAR-3                       23.6              14.8              394              432



                  OAR-4                       19.1              15.5             1190             1230



                  OAR-6                       36.9               6.1              117              160


                  OAR-Rl                      11.5               7.5              581              600


                  SAR-2                       32.1               9.7              469              511


                  SAR-3                        5.8               2.2              393              401


                  SAR-5                       39.6              25.4              901              966


                  SAR-6                        8.7               7.5              500              516


                  Washington ship QMDCI


                  WSC-1                        7.2               8.4              385              400


                  WSC-2                        7.2               8.8              451              467


                  WSC-3                        6.3               6.2              430              443


                  WSC-5                        8.7               6. 1             106              121


                  WSC-6                        5.6              17.3              281              304


                  OWSC-1                       9.9              66.2              604              680


                  OWSC-2                      44.2              36.1              952             1030


                  OWSC-3                      130.0              6.6              293              430





                                                                          31


                                                                      74











                                                                                                              Wade et al.



                   St& ED.                      PAH              SHC            ucm               THC



                   OWSC-RI                      78.3             54.5            4080             42  10


                   SWSC-2                       4.4              3.7              555             563


                   Potomac River



                   PR-l                         29.1             5.9              132             167


                   PR-2                         3.6              13.5             110             127


                   PR-3                         3.7              13.4              93             110


                   PR4A                         3.6              13.0             109             126



                   TiM Buin



                   n-l                          11.6             3.7              380             395



                   TB-1.5                       9.8              14.8             595             620


                   TB-2                         3.8              3.5              162             169



                   TB-3                         8.7              19.3             300             327



                   TB-4                         4.9              12.2             439             456



                   TB-5A                        4.8              19.5             954             978



                   TB-6                         3.8              3.9              171             179


                   OTB-I-l                      6.9              1.2               86               94


                   OTB-1-2                      8.0              10.7             285             304





                                                                          32


                                                                     75






                                                                                                                Wad' e et al.


                   Sta. ID.                    PAH              SHC              uCM               THC
                   OTB-2                       10.6               3.0             143               177

                   OTB-3                         5.0              5.9             449               460



                   OTB-4                       11.6             22.1              629               663



                   OTB_5                       10.6             22.0              739               771



                   STB-2-1                       9.0            12.1              1490             1500



                   STB-2-2                       8.6            11.3              %5                985




                 *Concentrations inag per gram dry weight. PAH-polycyclic aromatic hydrocarbons; SHC-

                 saturated hydrocarbons; UCM-unresoIved complex mixtm; THC-total hydrocarbons.

                 Station Ms. Akr6ng with the prefix (0) indicate samples that were taken directly in-front

                 of an sewer outfall, while the prefix (S) indicates samples that were taken in a sewer.

                 Stations AR-5, PR-4 and TB-5 were sampled and analyzed in triplicate and the average

                 value is reporte&



















                                                                          33


                                                                      76











                                                                                                Wade et al.


              TaWe 2. Conamtrations of total cWordane, DDT, and PCEs from the various study




               SbL M.                  Chlordane               DDT           PCB


               King= lAke


               KL-I                          %                 36            650


               KL-2                         110                65            530


               KL-3                         120                61            460


               KL-4                         ISO                76            520


               KL-S                         140                78            .660


               Anacostia Rim


               AR-I                         140                78            710


               AR-2                          91                56            510



               AR-3                         110                77            770


               AR-4                          89                120           2200


               AR-5A                         58                55            490



               AR-6                          28                29            220


               OAR-I                        120                110           390










                                                               34


                                                             77










                                                                                                  Wade et al.




                ShL M.                  Chlordane                DDT            PCB



                OAR-2                          120               100            1300


                OAR-3                          33                 44            940


                OAR-4                          93                261            480


                OAR-6                          38                320            340


                OAR-RI                         23                 54            140


                SAR-2                            5                58              89


                SAR-3                          26                 23              75


                SAR-S                          140                69            790


                SAR-6                          17                 26            1500


                EASAJ922100 Shi2 ChAuncl


                WSC-1                          14                 42            390


                WSC-2                          19                 36            330


                WSC-3                          18                 30            310


                WSC-5                          28                 36            300


                WSC-6                          17                 15            140


                OWSC-1                         39                 51            m


                OWSC-2                         64                 58            3200




                                                                  35


                                                               78











                                                                                              Wade et al.




               Sta. M.                CWordane               DDT            PCB



               OWSC-3                       130                450          880



               OWSC-RI                      30                 150          2800



               SWSC-2                        5                  7           260



               Potomac Riv
               'PR-1                        42                 100          270


               PR-2                          7                 10             68



               PR-3                          5                  7             73


               PR-4A                         9                 11             70


               Tidal Basin


               TB-l                         25                 160          610



               TB-i.5                       17                 170          500



               TB-2                          6                 23           110



               73-3                         14                 88           250



               TB-4                          8                 76           240



               TB-SA                         a                 39           190


               Tj"                           7                 29           150


               OTB-1-1                       4                 58           110





                                                               36


                                                            79











                                                                                                              Wade et al.




                 SUL M.                     Chlordane                  DDT               PCB



                 OTB-1-2                            14                   120             400



                 OTB-2                                7                  150             240


                 OTB-3                              10                   75              1300



                 OTB-4                              50                   goo             3400



                 OTB-5                              15                   so              380



                 STB-2-1                            10                   43              730



                 STB-2-2                            38                   91              290







               *Concentrations in ng per S= dry weight. Station Ms. starting with the

               prefix (0) indicate samples that were taken directly in-front of an outfall,

               while the prefix (S) indicates samples taken in a sewer. Stations AR-5, PR-4,

               and TB-5 were sampled and analyzed in triplicate, these data are the average.

               Chlordane is the E of a + -f-chlordane and cis + traw + nonachlordane;

               DDT is the E of DDD + DDE + DDT (2,4'+ 4,4' forms); PCB is the E of

                77 congeners.












                                                                         37


                                                                       80









                                                                                                          Wade et al.


              Table 3. Comparison of adected organic data frons various shmes in the region.!

                      PCBS               PAIb              DDT             Chlordanes        lAcation                 Sow

                          68-2203              4-29             7-160               5-155    Washington, 15T.         '17his Stu y9

                         4.80000                NW                 ND                   ND   Baltimore Harbor         EPA (1987)

                     < 100 - 2400                ND        < 10 - too                0-70    Schuykill River, PA.     EPA (1987)

                               ND                ND                ND                   ND   Potomac Estuary          MDE (unpub. datar

                             7-96        0.03-1.11            0.2-4.8             0.2-2.4    Lower Ches. Bay          NOAA (1991)

                            1-100        0.04-0.93            0.2-6.2              0.1-10    Middle Ches. Bay         NOAA (1991)
        OD
        I-W                 1-450         0.07-5.3           4.9-21.7             0.6-8.1    Upper Ches. Bay          NOAA (I"l)



               Concentrations of PCBs, DDTs. and chlordane are in ng per gram, and PAHs am in #g per gram dry weight. "Only river or basin sediment samples are
              presented for this study. *ND - No data. 'Maryland Department of die Environment.











                                                                                            38











                                                                                          Wade et al.



             Figure Captions:

             Figure 1. General study area indicating the locations of Tidal Basin, Washington Ship

             Channel, Kingman Lake, and the Potomac and Anacostia rivers. Arrows located around the

             shoreline indicate locations of outfall and sewer samples.



             Figure 2. Hydrocarbons and chlorinated-hydrocarbons in sediments of the Anacostia River.

             Transect is from the mouth of Kingman Lake (KL-5) to the confluence of the Anacostia and

             Potomac rivers (PR-4).



             Figure 3. Outfall, sewer, and basin or channel sediment series of the Tidal Basin and

             Washington Ship Channel: Total PAH and Hydrocarbons.



             Figure 4. OutfWl, sewer, and river sediment series in the Anacostia River: Total PAH and

             Hydrocarbons. The bottom panel highlights specific sewer and outfall series of the river.



             Figure 5. Outfall, sewer, and basin or channel sediments of the Tidal Basin and Washington
             Ship Channel: Total chlordanes', DDTs, and PCBs.


             Figure 6. Outfkll, sewer, and river sediments of the Anacostia River: Total chlordanes,

             DDTs and PCBs. Ile bottom panel highlights specific sewer and outfO series of the river.




                                                         39


                                                         82







                  9EORGETC


                    K   Oddge
                                                                                Ir             .;ColuMbla

                                                                                    P
                                                                                        I, a  't
                         TIMM   Is               . . I              Y                  ii
                                                             3
                                          F
                                             o
                                            o e"
                                          A A




                                                                                                                                               RF
                                  2
                                02                                                                                                           Sted
                                                         5
                                                    04
                                                              0
                                                         03

                                                                       0
                                                                         2

                                                                      4p
                f 4
               V4@ ;


                                                                                                                                             enn
                                                                                                         U.S. NMV
                                                                                                   5        yord
                                                                       Ir
                                                                                03
                                                                                                            *3       A      11 th Sireel Br.
                                                                                                                      2
                                                                                          S. Caphol   L4
                                                                                          SL
                                 I - uq,
                                                                                                              4
               41
                                                                                                                        3
                                  k.
                Ri                                                                 5

                                                                                              A5
                                                                                                                 Key:
                                                                     'P                  A5
                                                                                                                  o  Tidal Basin (TB)
                                                                                     PON
                                                                                rr *5
               ,Jf                                                                                                   Potomac River (PR)
                                                                  03
                                                                            pakt          Pit.                       Washington Ship Cha
                                                                A               84
                                                                                                                  A  Anacostia River (AR)
                                                                                                                  o  Kingman Lake (KL)
                                                                         <
                                                                                                                                   "all
                                                                         rn                                          sewer
                                                                                    .,A


                                                                                                                                     motors
                                                                                                                Scale:
                                                     ".,t                                                     0    5M    1000
                                          V.


                                          M,.














                    40                                                2000
                          [M PAH ED THC E]UCMI

                    30                                                1500




                    20                                               --1000




                    10                                               ..500




                      0                                              0
                           5 AR-1 AR-21'AR-3 AR4'AR-S'AR-6 WSC-d PR-4


                   3.0                                                200

                              PCB     DDT     Chlor
                   2.5--

                                                                     -150

                   2.0
                                                                         cc


                                                                      100

                  91.0
                                                                     so

                   0.5--



                   0.0 4                                             0
                        Kl,-S'AR-l'AR-2 AR     14AR-5iAR-s "WSC-d PR4

                                        Station ED
                                                           -An




                        KL-;





























                                            AR-









                                             84
                                                             c         -ell aa)














                                                    Tidal Basin
                             100                                                        5000
                                                                                               c
                                     JIMPAHOTHC                                                T
                                                                                               u
                             80                                                       --4000   0
                                                                                               c
                                                                                               tic
                             60                                                       --3000


                                                                                               c
                             40                                                         21000



                             20                                                       --1000


                              0.                                    1 i4'1 5'1  2       0

                                          Sediment             Outfan          Sewer

                             100           Washington Ship Chamel                       5000
                                                                (62o)      4LU)
                                            PAH      THC

                                                                            @-@000)
                          T   80                                                       ..4000

                              60  - -                                                   3000     V


                                                                                       -.2000
                              40  - -



                              20                                                        1000

                                       in  ifl in
                                       Mf,EI.
                               0        1 '2 '3    5 '6       1          R1     2  1   10
                                          Sediment             Outfan          Sewer
                                                      Station ED
                                             L34 j. 2



                                                             85







                     20               Tidal Basin               800
                                                    (4200)
                            KB     Dar   Chlor
                   .c
                   E 15                                         600

                   c


                     10                                         400


                   u

                   09 5                                         200


                      0        A.                               0   u
                                 3 4 5 6                 1 2
                              Sediment        Outfau     Seiver

                     20         Washington Ship Channel         800
                                                    CZIOO)          c
                           (EPCB JJDDT E:]ChIQrJ                    T

                     15                                         600



                     10                                         400



                      5                                        --200



                      0                                         0
                            1 '2 '3 5 6    '1             2 '
                              SedimerA         Oudau      Sewa
                                       Station ED
                        1@


                            - @52           1 2 3 4 5



                                                   t
                                               2 3 R1









                                                                            C'@
                                                  86









                                  Total PCB (ug/g-fine grain)                    Total PCB (ug/g-fine g
                                                                           C@
























                                                              PI

                         tA

                         0
                                     wwxmmmm@







                                               t
                              Chlordane and DDT (ug/g-fine grain)           Chlordane and DDT (ug/g-rj
                           0







                      200          Anacostia River        5000
                            @M PAH  THC                       C
                                                         --4000
                    E 150                                     c


                                                          3000

                                                              cm
                      100

                                                         -1-7000



                                                         .1000



                        0                                 0
                           1    4 5 6 1 2 3 4 6 Rl 2 3 5 6
                             Sediment    oudan    Sewer


                      200                                 5000
                               PAH   THC

                                                         ..4000
                      ISO

                                                          3000V

                      100                                     c
                                                         ..2000  '6

                       50
                                                         -1000



                                                         '0
                        0

                           "-2 SAR-2 AR-4 SAR 3 AR-5 OAR-6
                                    Station ED"



                                                      Ft@
                                       88














                           Reprint 4


          Pistribution and Sources of Trace Metals
          in Tidal River Sediments of Washington,
                              D.C,

          David J. Velinsky, Terry L. Wade, Christian E.
            Schlekat, Beth L. McGee and B.J. Presley













                               89










                   Distribution and Sources of Trace Metals to Tidal River Sediments of Washington,  D.C.




               David 1. Velinsky,

               Interstate Commission on the Potomac River Basin, Suite 300, 6110 Executive Blvd. Rockvule, MD

               20852 (Tel: 301-994-1908)



               Terry L. Wade

               Geochemical and Environmental Research Group, Texas A&M University, College Station, TX

               77845 (Tel: 409-690-0095)



               Christian E. Schlekat', Beth L. McGee2

               Maryland Department of the Environment, Toxics Registries and Analysis Program, Baltimore, MD

               21224, and



               B.J. Presley

               Department of Oceanography, Te xas A&M University, College Station, TX 77845

               (Ttl:409-945-5136)




               Present Addresses:

               'Science Application International Corporation, 165 Dean Knauss Drive, Narragansett, RI 02882

               (Tel: 401-782-1900)

               2EJniVersity of Maryland, Wye Research & Education Center, Box 169, Queenstown, MD 21658

               (Tel: 410 -827-8056)





                                                             90





                                                              Abstract                                Velinsky et al.

                       Fifty-four bottom sediments were collected from the Potomac and Anacostia rivers, Tidal

                Basin, and Washington Ship Channel in June 1991 to define the extent of trace metal contamination

                and elucidate source areas of sediment contaminants. Sediment samples also were collected directly

                in front of and within major storm and combined sewers that discharge directly to these areas. Trace

                metals (e.g., Cu, Cr, Cd, Hg, Pb and Zn) exhibited a wide range in values throughout the study area.

                Sediment concentrations of Pb ranged from 32.0 to 3630 Ag Pb g-1, Cd from 0.24 to 4.1 Ag Cd g-1,

                and Hg from 0.13 to 9.2 jug Hg g-1, with generally higher concentrations in either outfall or sewer

                sediments compared to river bottom-sediments. In the Anacostia River, concentration differences

                among sewer, outfall, and river sediments, along with downriver spatial trends in trace metals suggest

                that numerous storm and combined sewers are major sources of trace metals. Similar results were

                observed in both the Tidal Basin and Washington Ship Channel. Cadmium and Pb concentrations are

                higher in specific sewers and outfalls, whereas the distribution of other metals suggest a more diffuse

                source to the rivers and basins of the area. Cadmium and Pb also exhibited the greatest enrichment

                throughout the study area with peak values located in the Anacostia River, near the Washington Navy

                Yard. Enrichment factors decrease in order of Cd > Pb > Zn > Hg > Cu > Cr. Between 70 and 96 %

                of sediment-bound Pb and Cd were released from a N27purged IN HC1 ]each. On average, :9 40%

                of total sedimentary.Cu was liberated, possibly due to the partial attack of organic components of the

                sediment. Sediments of the tidal freshwater portion of the Potomac estuary reflect a moderate to

                highly contaminated area with substantial enrichments of sedimentary Pb, Cd and Zn. Ile sediment

                phase the contains these metals indicates the potential mobility of the sediment-bound metals if they

                are reworked during either storm events or dredging.









                                                                91







                                                                                                            Velinsky et al.



                                                               Introduction

                         Sediment contamination problems have been documented for an increasing number of marine

                 and freshwater areas in the U.S. (Lyman et al. 1987; NAS 1989; NOAA 1990). Sediments are a

                 major reservoir fbr anthropogenic contaminants (e.g., trace metals) due to the particle-reactive

                 behavior and low water solubility of many pollutants (Young et al. 1985; Olsen et al. 1982). Trace

                 metals in sediments can affect aquatic life as well as recreation and human health by entering the food

                 chain (i.e., animal and plant life). Also, restrictions on the handling and disposal of contaminated

                 sediments may raise the cost of dredging navigational waters to prohibitive levels. It is therefore

                 imperative to have an accurate assessment of the extent of sediment contamination in a given location

                 and imowledge of the source(s) of the pollutants.

                         There are few published data on the distribution and sources of potentially toxic inorganic and

                 organic chemicals in the tidal freshwater rivers of the Washington, D.C. area. Studies by Pheiffer

                 (1972) and Martin et al. (1981) indicated that the concentration of trace metals were highest around

                 the District of Columbia and decreased downstream. Recent studies in the urban Potomac and

                 Anacostia rivers have shown a wide range in organic and inorganic contaminant concentrations with

                 limited areas of higher metal concentrations OCPRB 1990).

                         Direct dumping, urban runoff, atmospheric deposition, and industrial and municipal

                 discharges, as well as upstream runoff are some possible sources that contribute to the loadings of

                 anthropogenic chemicals to riverine and coastal sediments. River runoff includes contributions from

                 chemical weathering and erosional processes as well as upstream anthropogenic sources. While the

                 extent of direct dumping is difficult to assess, 01senholler (1991) estimated that urban runoff (e.g.,

                 sava runoff) represents a major source of trace metals to the tidal Anacostia and Potomac rivers. In


                                                                     2




                                                                     92








                                                                                                       Velinsky et al.

                older cities like the District of Columbia, a major source of trace metals and other contaminants is

                runoff from combined sewer outfalls (00s). Ilerefore, runoff and overflows through CSOs may

                have a substantial impact on the sediment quality in the Anacostia and Potomac rivers.

                       Ille spatial distribution of anthropogenic chemicals may help identify their source areas.

                C;ertain chemicals, for example, may have diffuse sources yielding distributions with no consistent

                geographical trend. Other chemicals, however, may have a specific source (i.e., point source) from

                either an industrial or municipal facility or chemical spill that would be indicated by higher

                sedimentary concentrations in a specific area. Different geographical trends may be reflected not just

                in concentration gradients but also by the distribution within certain groups of metals. The objectives

                of this study are to determine geographical trends, elucidate possible source areas, and discuss the

                sediment speciation of trace metals around the District of Columbia. To accomplish this, sedimentary

                .concennflons, of trace metals will be compared to concentrations in sediments sampled from sewers

                lboth combined and storm) that drain into each respective area.



                                                        General Study Area

                       The District of Columbia (DQ lies along the fall line at the boundary between the Atlantic

                Coastal Plain and the Piedmont Plateau, and is at the head of navigation of the Potomac estuary (Fig.

                1). 7be western and northern sections of the DC area are part of the Piedmont, which is underlain by

                deformed meta-sedimentary and meta-igneous rocks. From the mid-section of the city to the south is

                the Coastal Plain which contains unmetamorphosed fluvial and marine sediments (Reed and

                Obermeier 1989).

                       Presently, there are three major rivers or streams in the DC area: the Potomac and Anacostia

                rivers, and Rock Creek, which drains into the Potomac River just south of Georgetown (Fig. 1).


                                                                  3



                                                                  93








                                                                                                            Velinsky et al.

                 Average yearly flows for the Potomac River at Chain Bridge, Anacostia River, and Rock Creek are

                 1.03 X 1010, 1.16 X 101, and 5.5 X 10" ml yr', respectively. Even though the drainage areas of the

                 Anacostia River (310 km@ and Rock Creek (160 km@ are small compared to the Potomac River (e.g.,

                 at Chain Bridge, 29600 km@, both water bodies drain predominantly urban environments.

                         During the past 200 years, the DC riverscape has been altered by sedimentation, dredging,

                 and filling (Williams 1989). The Tidal Basin (surface area of 0.4 km@, with an average depth of

                 approximately 2 m, receives inputs from the Potomac River as well as storm water runoff and

                 atmospheric deposition. The Washington Ship Channel, located in the southeastern section of DC, is

                 connected to the Tidal Basin in the north section via a floodgate and to the Anacostia River at the

                 southern end (Figure 1). The center of this channel has been dredged in the past with bottom depths

                 rw&g from < I m to approximately 8 m. The Washington Ship Channel is bordered by a park on

                 the western side and residentiallcommercial development on the eastern side.

                         The flow of the Anacostia River is controlled by streamflow of the Northeast and Northwest

                 branches, which join at Bladensburg (MD). The tidal waters in the lower Anacostia River, South of

                 Bladensburg, have a long residence time (e.g., 35 days) due to the large volume relative to the runoff

               )of the river. Therefore, it resembles a lake more th  an a river (Scatena 1987), and allows suspended

                 sediments to settle within the tidal portion of the river. Sedimentation rates are reported to be 3.2 g

                 cm:* yr' or 1.9 cm yrI on a dry-sediment basis (Scatena 1987). While the center channel of the

                 Anacostia River has been dredged in the past, depths outside the channel generally range from 0.5 to

                 5 m.

                        7bere is potential for historical contamination of the sediments in the study area due to past

                 shipping and boating uses, and inputs via combined and storm sewer runoff. Approximately 30 storm
                 and six combined sewers discharge into the lower Anacostia River (i.e., south of the Kingman Lake


                                                                    4




                                                                    94








                                                                                                     Velinsky et al.

               area to Greenleaf Point at the mouth of the Washington Ship Channel). These sewers drain an area of

               approximately 14 1=2, or 22% of the drainage area of the Anacostia River within the District of

               Columbia. Approximately 54% of the total drainage area of the Anacostia Basin is urban (lCPRB

               1988).

                       Numerous storm sewers (no combined) drain into the Tidal Basin and Washington Ship

               Channel. Of the six outfalls at the Tidal Basin, the largest drains the Constitution Ave. and

               Smithsonian Mall areas. The nine storm sewers that empty into the Washington Ship Channel drain

               an area from approximately Independence Avenue (Smithsonian Institution), 13th Street, and 4th

               Street, in southwest Washington, D.C. Numerous marinas also line the upper Washington Ship

               Channel.




                                                Sampling and Analytical Methods

                      River and outfall sediment samples were obtained from the Tidal Basin (TB), Washington

               Ship Channel (WSQ, Kingman Lake (U), Potomac River (PR) and Anacostia River (AR) in June,

               1991 (Fig. 1). In the Tidal Basin, six stations were sampled with six additional samples taken at the

               mouth of specific outfalls (OTB) that enter the basin. At one station (TB-5), three separate samples

               of three grabs each were taken within a radius of approximately 5 m to assess small scale spatial

               variability.

                      In the Potomac River, four stations were sampled from the mouth of Rock Creek to the

               confluence of the Anacostia and Potomac rivers and the Washington Ship Channel (Fig. 1). No

               samples were obtained from sewers that drain into the Potomac River. In the Washington Ship

               Channel, five stations were sampled along the eastern side of the channel. Seven stations were

               occupied in the Anacostia River. Anacostia River samples were taken on the northern side of the


                                                                5




                                                                95








                                                                                                          Velinsky et al.

                 river outside the main center channel. As in the Tidal Basin, one station from the Potomac and

                 Anacostia rivers (PR-4 and AR-5, respectively) was sampled in triplicate (i.e., 3 separate samples of

                 3 grabs each).

                        Outfall and sewer sediment samples also were obtained from both the Anacostia River and

                 Washington Ship Channel (Fig. 1). In the Washington Ship Channel, four outfall sediment samples

                 (OWSC) were obtained in conjunction with one sample from a sewer (SWSC) that drains along Maine

                 Ave., S.W. In the Anacostia River, six outfall sediment samples (OAR) were obtained as well as

                 fbur (one combined and three storm) sewer samples (SAR) from various locations along the river. In

                 Kingman Lake, a total of four sediment samples were obtained (Fig. 1), but no storm or combined

                 sewer samples or outfall samples.

                        A Hydrolab Surveyor H was used to collect dissolved oxygen, temperature, condudivity, pH,

                 and water depth just above the sediment surface. Sediments were collected with a stainless steel

                 petite-Ponar grab sampler (0.023 ml) that was acetone rinsed at the beginning of each day. The

                 sampler was inspected for possible cross-contamination (i.e., sediment from previous station) and

                 rinsed with ambient water at each station. The top 2 to 3 centimeters of sediment not in contact with

                 the sides of the sampler were removed and placed into a pre-cleaned Pyrex-glass bowl. This process

                 was repeated three times until sufficient sediment was obtained.

                        Sediments were mixed with a pre-cleaned stainless steel spoon until homogeneous in both

                 texture and color. Trace metal and grain size samples were placed into separate Zip-loc plastic bags.

                 Sediment aliquots for acid-volatile sulfur (AVS) were sampled first'and placed into 50 ml plastic

                 centrifuge tubes and quickly frozen using dry ice (-78*C). All other samples were placed in coolers at

                 approximately 4"C while in the field. Once on shore, sediment samples for metal and AVS analyses

                 were placed in a freezer at -209C, whil e samples for grain size were kept at VC.


                                                                   6




                                                                   96








                                                                                                          Velinsky et al.

                        All materials coming in contact with the samples were either glass or metal. All glass bowls

                were soaked in 0.5N HCI overnight, rinsed with distilled deionized water (DDW) and solvent rinsed

                with methanol, dichloromethane, then hexane (Burrick and Jackson, Inc.) and allowed to air dry in a

                bood. All metal utensils were washed similarly but without using the dilute acid rinse.

                SedimeW= trace     metals. Analyses for trace metals were identical to NOAA Status and Trends

                techniques (Brooks et al. 1988) and are briefly outlined. Samples were digested in 50 ml closed

                all-teflon *bombs* (Savillex Co.). Accurately weighed sediment aliquots (ca. 200 mg) were digested

                at 13M in a mixture of nitric, perchloric and hydrofluoric acids. A saturated boric acid solution was

                then added to complete dissolution of the sediment and the digest was brought to a known volume.

                Standard reference materials and blanks were digested and analyzed with every batch of samples.

                        Concentrations of iron (Fe) and zinc (Zn) were determined by flame atomic absorption

                spectrometry (AAS), while sediment concentrations of cadmium (Cd), chromium (Cr), copper (Cu),

                and lead (Pb) were determined by a Perkin-Elmer Zeeman 3030, equipped with an HGA-6W furnace

                and AS-60 autosampler. Standard reference materials (e.g., NIST and NRCQ and spiked samples

                were used to evaluate analytical performance. Based on 10 separate analyses of the reference

                materials over the course of the project, the accuracy and precision of the analyses are approximately

                  10 % for all metals.

                        Mercury (Hg) was determined by cold vapor AAS on an aliquot of the same digest used to

                determine other trace elements following a "head space" sampling procedure (Brooks et al. 1988). A

                Laboratory Data Control Co. UV monitor with a 30 cm path length cell was used for Hg

                   amin2tionS.

                        Glassware, plasticware, and reaction vessels were cleaned first by soaking in Micro cleaning

                solution for 24 hrs and then rinsed with distilled water. Glassware and the reaction vessels were then



                                                                   7




                                                                  97








                                                                                                       Velinsky et al.

                soaked in an acid bath (50%v/v HN03) for 24 hrs, rinsed with distilled deionized water (DDW), and

                air dried in a laminar flow hood in a dust free environment. Other plasticware used in these

                procedures were either used only a single time or reused after washing with Micro solution,

                appropriate acids (i.e., either HCl or HNO@, depending upon resistance to attack) and DDW.

                Acid Extractable Metals. Frozen sediment samples were quickly thawed and homogenized, with

                aliquots (ca. 1-2 grams) placed into pre-cleaned and tared 50 ml centrifuge tubes. Samples were

                accurately weighed and rapidly frozen using liquid nitrogen then stored at -2M until extraction. Wet

                and dry weights were determined from separate aliquots of the sediment mix.

                        For extraction, samples were placed in a 112-purged glove bag and allow ed to thaw. De-

                aerated IN HCl (Baker Intra-analyzed grade) was added to a volume of 25 ml and the centrifuge

                tubes were tightly capped. Ile samples were removed from the glove bag and mixed on a Vortex

                mixer fbr one hour. After centrifugation and filtration to separate the solids, samples were

                transferred to pre-cleaned screw cap polyethylene bottles and the metals analyzed by AAS.

                       While this leaching technique is not specific for a given sediment phase (Tessier et al. 1979),

                it should provide an indication as to the potential mobility (Forstner 1979) and possible biological

                avaflabUity of the trace metals (Luoma and Jenne 1976; Luoma 1983; Di Toro et al. 1990). Trace

                metals released under the conditions used in this study may derive from the exchangeable, carbonate,

                amorphous Fe/Mn oxides, and metal sulfide sediment phases along with a fraction of the organic

                component of the sediment (Tessier et al. 1979; Pickering 1981). Malo (1977) showed that a cold

                0.3N HCI solution extracted a significant fraction of the metals from surface coatings and only

                minimml structural components are attacked. In this regard, a cold IN HCI solution was shown to

                dissolve only natural and synthetic hydrous amorphous iron oxides, whHe leaving more crystalline

                oxides (e.g., magnetite, goethite, and hematite) intact (Chao and Zhou 1983). During this study,


                                                                  9




                                                                 98








                                                                                                         Velinsky et al.

                sampling and extraction (i.e., in a N2-purged glovebag), exposure of the sediments to air was kept to

                  M*n*M11m. Furthermore, field experiments showed no loss of acid-volatile sulfur (AVS) during

                sampling in the field (Velinsky unpublished data). Therefore, the contribution of metals that are

                bound or precipitated to the monosulfide phase should also be extracted using IN HCl (Rapin et al.

                1986).

                       To monitor precision and recovery of metals, several replicates of an in-house sediment

                standard (HS-2, collected from the Mississippi River Delta) were included in the preparation. Two

                unspiked replicates were analyzed, along with four replicates that were spiked with known amounts of

                analytes prior to sample processing. Two blanks were included to evaluate contamination which was

                insignificant compared to the concentrations observed.

                Acid Volatile Sulfur. Acid volatile sulfur, predominantly iron sulfide, was determined by the method

                of Cutter and Oatts (1997). In brief, 20-80 mg of frozen sediment (wet/dry weight ratio determined

              -on a separate aliquot) was extracted using 0.5N HCI and the evolved hydrogen sulfide (H2$) was

                purged from the solution and trapped in a glass U-tube filled with Porapak QS, immersed in liquid

                nitrogen. After 15 min of purging and trapping, the U-tube was removed from the liquid nitrogen to

                volatilized the H2S, which was chromatographically separated from other volatile compounds prior to

                detection by a photoionization detector. Detector signals were processed by a HP-3390A digital

                integrator/plotter.

                       Calibration of the detector was accomplished using a known quantity of anhydrous sodium

                sulfide (Alfa Products). Samples were run in either duplicate or triplicates and precision was

                generally beau than 10% as relative standard deviation.

                Q=ic Carbon and Grains Size, Total organic carbon (OC) was determined by infra-red absorption

                after combustion in an 02stream, using a LECO WR-12 Total Carbon System. Sediment grain size


                                                                  9




                                                                  99








                                                                                                      Velinsky et al.

               was determined by the procedure of Folk (1974), utilizing sieving to separate gravel and sand

               Mwtions from the clay and silt fractions. The latter fractions were subsequently separated by the

               pipette (settling rate) method. Detailed descriptions of the methods utilized in measuring OC, CaC03

               and grain size are reported in Brooks et al. (1988).

                                                              Results


               Sediment Organic Carbon and Grain Siz

                       Organic carbon (OC) concentrations ranged between 2.5 and 6.4% on a dry-weight basis (dw)

               fbr all river and basin sediment samples with an average. of 4.0 ï¿½ 0.9 % OC (ï¿½ standard deviation;

               Table 1). Highest concentrations were observed in Kingman Lake and the Tidal Basin. Outfall

               sediment samples exhibited a greater range in OC concentrations than bottom sediments, with

               concentrations ranging from 0.7 to I I% OC. This wide range most likely reflects both the different

                    ible sources of OC and the physical sorting of particles (both size and composition) during runoff
               possi


               events.


                       The grain size distribution in the study area was fairly uniform, with river sediments

               predominately in the clay and silt size fractions (< 63 Am; Table 1). At a few stations, the sand

               fraction accounted for between 25 and 30% (e.g., WSC-5, PR-I and TB-3) of the total sediment.

               These locations may be areas of stronger currents in which fine-grain sediments do not settle. Outfall

               and sewer sediment samples exhibited a greater range in grain size, reflecting the physical sorting of

               particles in these often high-flow environments (rable 1).

                       Sewer sediment samples exhibited lower concentrations of OC than either river or outfall

               sediments, with concentrations averaging 1.0 ï¿½ 0.9% OC (n=5) for both storm and combined sewer

               sediments. The lower concentrations of OC also were reflected in the grain size distribution of these

               samples in which approximately 80% of the samples were in the sand-sized fraction. However, there


                                                                10




                                                                100








                                                                                                      Velinsky et al.

               was no iignificant relationship (p > 0.01, n=50) between %OC and the fraction of fine-grain

               sWiment for the entire data set.

               M"ribution and GeogrVlic Trends of Sedimentaa Trage Metals

                       Ile distribution of individual trace metals, presented on a whole-sediment basis (i.e., weight

               of metal per weight of dry whole-sediment), exhibited similar geographic trends within each river or

               basin (Table 2). In the Potomac River, highest trace metal concentrations were found at station PR-1

               (Table 2). Downstream from this station, sedimentary concentrations of all trace metals decreased,

               with station PR-4 exhibiting some of the lowest concentrations throughout this study. While no

               samples were taken upstream of Rock Creek as part of this study, previous studies (Pheiffer 1972;

               JCPRB 1991) revealed lower concentrations in the upstream area (i.e., from Little Falls to

               Georgetown).

                      .Concentrations of trace metals in Tidal Basin sediments were similar at all sites except for Cu

               and Pb at station 7B-1 (Table 2). Sediment concentrations of Cu and Pb at TB-I were 120 and 204

               pg g-I compared to 56.1 ï¿½ 8.0 and 93.8 ï¿½ 12.9'ag g' (average of five stations) in the basin,

               respectively. Grain size variations were small and do not account for the differences between TB-I

               and the other stations (Table 1).

                      Within the Washington Ship Channel, the distribution of all sedimentary trace metals reveal

               highest values at the head of the channel (i.e., stations WSC-I, 2, and 3) with decreasing

               concentrations downstream (Table 2). Lead concentrations decreased from elevated values of 183 and

               125 ;tg Pb g-I at WSC-I and WSC-3, respectively, to a low of 48.3 ;Lg Pb g-I at WSC-5. At station

               WSC-6, located at the confluence of the Washington Ship Channel and the Anacostia River, all trace

               metals incriased in concentration from those at WSC-5.

                       Results from the Anacostia River are presented as a transect from KL-5, located outside






                                                                101









                                                                                                             Velinsky et al.

                 Kingman Lake in the river, to PR-4, located just south of Hains Point at the confluence of the

                 Potomac and Anacostia rivers (Fig. 1). This transect includes WSC-6, located at the confluence of

                 ibe Anacostia River and the Washington Ship Channel. From station KL-5 to AR-3 Oust upstream of

                 the Washington Navy Yard), concentrations of Hg, Pb, Zn, and Cd were fairly constant, while

                 concentrations of Cr and Cu increased slightly (Table 2; Fig. 2). Sediment concentrations of all trace

                 metals were highest at station AR-4. The increase in trace metal concentrations from KL-5 and AR-3

                 to AR-4 was greatest for Hg, Pb and Cd with increases of 206%, 179% and 60%, respectively.

                 Sedimentary concentrations of all trace metals decreased downstream of AR-4. The largest decreases

                 were exhibited by Hg, Pb and Cd; concentrations decreased 600%, 1000% and 450%, respectively,

                 from AR-4 to PR-4. The general decrease in trace metal concentrations was not related to grain size,

                 as 90% of the sediment from stations between AR-5 and PR-4 was composed of silt and clay.

                         Triplicate sediment sample analyses revealed little variability in the distribution of all trace

                 metals in the Iocal" area (i.e., within a 5 m radius). Relative standard deviations (ï¿½ SD/mean X

                 100; n = 3) for all metals, TOC, and grain size were below 10%. Due to modest variations in grain

                 size, these results suggest that local-scale spatial variations in concentrations are small compared with

                 larger geographical changes observed in the Potomac and Anacostia rivers, and the Tidal Basin. This

                 may not be the case where sediment grain size and other bulk characteristics vary substantially.

                 Comparison between Sediments. Outfalls. and Sewers

                         For comparison of sedimentary trace metal concentrations between river, outfall and sewer

                 sediment samples, concentrations were divided by the fraction of fine-grain sediment in each sample
                 (i.e., sediment particles _-5 63,um). This Do;nwization procedure assumes that no contaminants are

                 associated with the sand-sized material, which only dilutes the level of contamination fbr a given

                 sample (NOAA 1991). Due to grain size differences between river, outfall, and sewer samples,


                                                                    12




                                                                    102








                                                                                                         Velinsky et al.

                normalization of the data resulted only in small changes of river or basin sediment trace metal

                wncentrations, but significant concentrations increases from the outfall and sewer samples.

                        Samples collected at five storm sewer outfaHs draining the Tidal Basin area had elevated trace

                ontal concentrations compared with basin sediments (Fig. 3). Material collected at OTB-4 and OTB-

                3 had the highest trace metal concentrations of the study (Fig. 3), with concentrations of Pb and Hg at

                station OTB4 of 1.9% Pb (i.e., 19400 jLg Pb g` fine-grain) and 50 Ag Hg g` fine-grain, respectively.

                As a comparison, sedimentary concentrations in the Tidal Basin ranged from 80 to 210jug Pb g" fine-

                grain and 0.3 to 0.5 ;&g Hg gl fine-grain, respectively. Elevated concentrations of Cu, Cd, and Zn

                also were evident at stations OTB-4 and OTB-3, compared with Tidal Basin sediments (Fig. 3). Two

                sediment samples (STB-2) collected from a sanitary sewer that drains the area along 15th Street,

                S.W., had extremely elevated concentrations of most metals (Table 2). Concentrations of Pb and Cd

                ranged from I to 8 % Pb (fine-grain) and 5.5 to 24 jug Cd g" fine-grain, respectively. This location

                was sampled twice during the study and concentrations of most metals exhibited substantial variation

                (Fig. 3).

                       Trace metal concentrations of outfall sediment samples surpassed those in the sediments of the

                Washington Ship Channel (Fig. 4). Concentrations of most trace metals increased from station

                OWSC-1 to OWSC-3 then decreased slightly at OWSC-Rl. For example, Pb concentrations ranged

                from 190 to 2400jug Pb g-I fine-grain between OWSC-I and OWSC-3, respectively, with highest

                concentrations at station OWSC-3. One storm sewer was sampled in the Washington Ship Channel

                area (SWSC-2). This sewer drains a small area between 9th and 10th Streets on Maine Avenue in

                amthwest Washington D.C.. The runoff from this area eventually feeds a larger storm sewer line

                dma flows into the Washington Ship Channel near it's head. Sewer-sediment trace metal

                concentrations were greater than the channel sediments, but not as high as some of the outfall


                                                                  13




                                                                  103








                                                                                                          Velvinsky et al.

                concentrations (Fig. 4). However, the concentration of Cd (17 Ag Cd g-1 fine-grain) in this sewer

                sediment sample was substantially higher than samples from the outfall or channel (overall range

                0.7 to 5.4 jLg Cd g" fine-grain).

                        As with the other sites, sediment concentrations of most trace metals decreased from sewer

                and outfall samples to the river sediments within the Anacostia River (Fig. 5). This is most evident

                between the storm sewer SAR-5 and its outfall OAR-3, and the river station AR-4. Station SAR-5 is

                located "up-pipe" from the outfall OAR-3 which is slightly upstream from station AR-4. Within this

                series, the concentration of Pb decreased from 970 ;Lg Pb g-' fine-grain at SAR-5 to 780 ;Lg Pb g"I

                fine-grain at OAR-3. The concentration of sedimentary Pb decreased further to 480 ;&g Pb g" fine-

                grain at AR-4. Sediment collected at station OAR-3 could be a mixture of outfall material and river

                sediments, reflecting the lower concentrations found in the river. Similar trends at these stations are

                noted for the trace metals Hg, Cd, and  Zn (Fig. 5).

                Dilute Acid-Leachable Metals


                        To obtain a better understanding of the sediment phase(s) that controls the distribution and

                cycling of trace metals, 15 river and basin sediment samples were extracted with a IN HCI solution

                under a N2-purged atmosphere.

                         A substantial fraction of sediment-bound Cd and Pb and to a lesser extent Zn and Cu, were

                released from the acid leach (Table 3). For all sediments, between approximately 70 and 96% of the

                total Cd and Pb was extracted, with an average of 84 ï¿½ 8 % Cd and 83 ï¿½ I I % Pb (n = 15), wh il e

                overall only 63 ï¿½ 8% of the total.sedimentary Zn was present in the IN HCI fraction. On average,

                :9 40% of the total sedimentary Cu was liberated, possibly due to the partial attack of the organic

                component of the sediment. Copper has been shown to be strongly complexed or bound to organic

                nwter' nd the IN HCI solution may only partially release the Cu bound to this fraction. Oxidizing


                                                                   14




                                                                   104









                                                                                                       Velinsky et al.

                acids or hydrogen peroxide would be better suited to release trace metals bound in the organic

                fraction (Tessier et al. 1979; Martin et al. 1987). Only 25 ï¿½ 4% of the total sedimentary Fe was

                released by this technique indicating that a significant fraction of the Fe is either more crystalline

                oxides, pyrite, or lattice bound. The Fe liberated from the sediments is most likely a combination of

                both amorphous iron oxides and iron monosulfide phases (i.e., Fes).

                                                              Discussion


                        Information on the sources and geochemistry of trace metal contamination are critical to

                management of the problem in the District of Columbia as well as other urban tidal freshwater

                environments. In the following sections, these topics are discussed to help determine the fate of

                contaminated sediments in urbanized estuaries.


                Sources of trace metals in the Washineton. D.C.. area

                        The geographical distributions observed in this study indicate that sources located within the
                Washington, D.C., area are major contributors to the levels of trace metals fbund in the sediments.

                Land and street runoff through the area's storm and combined sewer system are major sources. Also,

                drainage from stream flowing through the District of Columbia also can account for elevated levels

                of metals in various sections of the Potomac and Anacostia rivers. In this regard, runoff from Rock

                Creek to the Potomac River is the likely source of metals concentrations of the sediments around the

                confluence (Fig. 1). Studies by Phieffer (1972) and 1CPRB (1990) in the area upstream of the

                confluence revealed lower or similar concentrations of metals compared to downstream of Rock

                Creek. The drainage area of Rock Creek is approximately 60% urban, with numerous storm water

                disdbarges into the creek. These discharges are most likely the source of the higher concentrations

                Axwd at the confluence.

                        The Tidal Basin sediments are most likely influenced by storm water sewers that empty into it


                                                                  15




                                                                 105







                                                                                                             Velinsky et al.

                 (Fig. 1). The elevated concentrations observed at OTB-3 and 4 suggest that runoff through these

                 pipes is a major source of metals to the basin. These sewers drain the street area around 15th and D

                 Street, and. near Interstate 395, in southwest Washington, D.C. Because these pipes are storm

                 sewers, runoff from the numerous streets and highways in this area are a probable source. However,

                 the elevated concentrations of metals, especially Pb, in the sanitary sewer line adjacent to the basin

                 indicates an additional source. Prior to approximately 1990, the Bureau of Engraving and Printing
                 (BEP) discharged approx'imately 5 kg Pb day-' to the sanitary system. While this material was sent to

                 the Blue Plains Wastewater Treatment Plant (WWTP) for treatment and disposal, overflows into the

                 storm sewer system have been reported. (Friebele 1991). These overflows could be a possible source

                 of Pb to the Tidal Basin and other waterbodies within the District of Columbia. In 1990, a

                 pretreatment facility was completed to collect Pb and other contaminants before discharge to Blue

                 Plains WWTP. Although it is impossible to estimate the flux of trace metals to the basin from this

                 zdata set, the concentration gradients suggest that material flowing through these outfalls (i.e., samples

                 were taken directly in front of an outfall in the basin) are a dominant source of trace metal

                 contamination to the basin. Once the contaminants are introduced into the basin, dispersal of the fine-

                 grain material and associated trace metals yield the observed concentrations measured in the basin.

                         The upper end of the Washington Ship Channel is a semi-enclosed embayment in which the

                 water is partially flushed once per tidal cycle from water stored in the Tidal Basin. Numerous

                 bridges, both automotive and railroad, cross the upper end of the waterbody as well as four storm

                 sewers that drain into the upper end of the channel. As in the Tidal Basin, the concentration

                 differences between outfall and channel sediments, indicate that runoff from storm sewers is a major

                 source of trace metals. The higher concentrations of sedimentary trace metals at stations WSC-1,

                 WSC-2, and WSC-3 (Fig. 4) correspond to the higher concentrations at the outfall stations -OWSC-


                                                                     16




                                                                     106








                                                                                                           Velinsky et a].

                 RI, OWSC-3, and to a lesser extent OWSC-2. Station OWSC-3 is near a storm sewer that drains the

                 area between 12th and 13th Streets, S.W. (Fig. 4). This area was the site of a railroad yard and is

                 the site of numerous construction projects.

                         Trace metals distributions in the Anacostia River suggests a substantial source between

                 stations AR-3 and AR-4 and that runoff through OAR-3, is a source of trace metal contamination to

                 this section of the Anacostia River. Ile concentration differences between sewer, outfall and river

                 sediment samples at SAR-2, OAR-2 and AR-2 also indicate a source of trace metals from the sewer

                 system (Fig. 5). Concentrations of Pb and Zn at SAR-2, for example, are 37000 and 2300,ug g-I

                 fine-grain, respectively. Concentrations decreased at OAR-2, the outfall of the combined sewer from

                 which SAR-2 was taken. This decrease is most likely related to the mixing of river sediments with

                 outfall material. Station AR-2 is located slightly upstream of the outfall, and has concentrations lower

                 than, or similar to, the outfall sediments.

                         The gradual increase in sediment concentration of Cr, Cu, and Zn from KL-5 to AR-4

                 suggests a more diffuse input for these metals. Runoff from the numerous combined and storm

                 sewers that empty into this area, along with upstream transport are possible sources. Also, the river

                 width increases in this segment of the Anacostia as it approaches the Potomac River. This increase,

                 along with the tides, may extend the residence time of the water, enabling particulate material and

                 associated-metals to settle to the bottom and incorporate into the sediments (Scatena 1987).

                         Trace metal concentration gradients between sewer, outfall, and river sediment samples

                 suggest that runoff from the stormwater and combined sewer system is a major source of

                 Cnntizninan to the Anacostia River, Washington Ship Channel and Tidal Basin (Figs. 3, 4, and 5).

                 In all areas, highest sediment concentrations of trace metals were measured ftm either the sewer or

                 outfall sediments. Concentrations of Pb, Hg, and Cd, fbr example, were as high as 37000, 50, and


                                                                    17




                                                                   107








                                                                                                        Velinsky et al.

                24 #g g" fine-grain, respectively, in either the outfall or sewer samples. The trends in concentration

                between sewer, outfall and river sediments are especially noted at station AR-4 in the Anacostia

                River. While this data set indicates that runoff through the sewer system is a major source of trace

                nutals to the area, the magnitude of this source compared to other sources (e.g., atmospheric

                deposition, direct runoff, dumping) can not be quantified directly. Also, due to the nature and types

                of samples taken it impossible to pinpoint a specific source of trace metals. However, these results

                indicate specific areas of concern that warrant further investigation.

                Dilute acid-leachable metals

                        Results indicate that the mobility of trace metals in these sediments may be substantial. As a

                result of dredging or storm events, the redox environment of the surface sediment can change,

                liberating weakly-associated trace metals. These changes can be the result of oxidation of reducing

                sediment, and possible pH changes in weakly-buffered pore waters of freshwater sediments. These
                metals could then be potentially more available for biological uptake and transpoirt via water. For

                example, sediments in the rivers or basin contained a substantial amount of acid-volatile sulfur (AVS)

                which only exists in reducing conditions (Table 1; Goldhaber and Kaplan 1975). This sulfide fraction

                in these sediments is most likely metal monosulfides (e.g., XS, where X can be Fe, Cd, Cu, Pb, and

                Zn). Aeration of the sediment could release metals into the pore waters until they are bound into

                other phases such as Fe/Mn oxides (Lion et al. 1982). 71e oxidation of AVS (and pyrite) also could

                lower the pH of the sediments enhancing the release of mews to the pore waters. These results

                indicate that a substantial fraction of sedimentary metals could be released during events that rework

                or u2nsport the sediments (i.e., bioturbation, storm events, and dredging).

                Excess metals in the sediments around WasbingLQn. D.C.

                        A useful toot in expressing the degree to which a sediment is impacted from anthropogenic





                                                                  108







                                                                                                            Velinsky et al.

                   sources of trace metals is the enrichment factor (EF) (Trefrey and Presely 1976; Sinex and Heiz

                   1981; Helz et al. 1985; Windom et al. 1989). Normalization of the sediment to a reference element

                   wt associated with anthropogenic influences is a convenient approach to determine the degree of

                   sWiment contamination. Elements such as aluminum (Al) (Windom et al. 1989; Schropp et al. 1990),

                   lithium (M) (Loring 1990) and iron (Fe) (Trefrey and Presely 1976; Sinex and Helz 1981; Helz et al.

                   1985) have been used in the past. For this study, Fe was chosen as a normalizing element because 1)

                   it is the fburth most abundant metal in the earth with a crustal average of 3.5 % (Wedepohl 197 1); 2)

                   in most cases, anthropogenic sources are small compared to the amount of Fe naturally present; and

                   3) the ratio of metal to Fe is fairly constant in the Earth's crust. The enrichment factor is defined as:

                   EF = (X/Fe).A... /(X/Fe).j..             where X/Fe is the ratio of the trace metal (X) to the amount

                   of Fe in the sample.

                          In using the EF, a comparison to a sediment that is unimpacted by anthropogenic sources is

                   necessary [i.e., (X/Fe)...pj. Critical in this analysis is the choice of metal to Fe ratio for

                   "unimpacted" sediments. Past studies have compared sediments to the distribution of trace metals in

                   the earth's crust (Sinex and Helz 1981; Helz et al. 1985). While this approach is useful, it may not

                   account fbr natural variations in sediment types of different geological regions. One way to account

                   for this variability is to derive a ratio from munimpacted" sediments in the general area of interest

                   (Windom et al. 1989; Schropp et al. 1990). In the present study, all samples have the potential to be

                   impacted above natural levels. Therefore, data from samples taken in the Chesapeake Bay drainage

                   area (including the Potomac River) were used to derive metal abundances in the general area Q40AA
                   1991). Sixteen stations* in Chesapeake Bay that are relatively remote from such anthropogenic sources

                   as Baltimore Harbor and Elizabeth River were used. Ile ratios obtained from the regression of the

                   NOAA (1991) data are presented in Table 4 along with data from other areas. The ratios derived


                                                                      19




                                                                   109








                                                                                                       Velinsky et al.

                from Helz et al. (1985) are from the average composition of coastal plain deposits from northern

                Chesapeake Bay, while the data from core 1314 (Goldberg et A. 1978) are from a location just south

                of the mouth of the Potomac River. These data, along with values from average continental crust and

                soils, are similar in magnitude (Table 4). Therefore, the average values were used to calculate the EF

                fbr each metal.

                       The degree to which sediments in the study area are enriched in trace metals vary from metal

                to metal. These variations can be due to a number of factors including 1) choice of (X/Fe).-ip.., 2)

                biogeochemistry of the metal, and 3) sources of metals to the study area. While these calculations

                use the average (X/Fe).*.,
                                           ,,, these values can vary. For example, the Cd/Fe value ranges from

                0.01 to 0.09 while the Pb/Fe value ranges from 4.0 to 9.4. While these values may change the

                magnitude of the EF, the geographic trends should not change. In light of these factors some general

                trends and features are obtained ftom the EF data (Table 5).

                       The EFs are generally highest for Cd and lowest for Cr and Hg (Table 5), with intermediate

                values for Pb and Zn. Except for Hg,. all trace metals are enriched in Kingman Lake and the upper

                Anacostia River (KL-1 to AR-4). This is especially evident at station AR-4, which has the highest EF

                in the study area for all trace metals. The EF decreases in order of Cd > Pb > Zn > Hg > Cu > Cr at

                station AR-4. Other stations also indicate higher enrichments (and possible sources) of trace metals.

                These include WSC-I, 2, and 3 in the upper end of the Washington Ship Channel; station PR-I at the

                mouth of Rock Creek in the Potomac River; and TB-I in the northern embayment of the Tidal Basin.

                The order of enrichment (i.e., Cd > Pb > Zn > Hg > Cu > Cr) for these stations are similar to AR-4

                with some small variations between Hg and Cu.

                       The El's indicate potential anthro pogenic sources for trace metals in the sediments of the

                Washington, D.C., area. These source materials are enriched in Cd and Pb relative to the other


                                                                 20



                                                                 110








                                                                                                          Velinsky et al.

                metals (Table 5). Areas that are impacted more by anthropogenic sources include the mouth of Rock

                Creek, the northern embayment of the Tidal Basin, the upper end of the Washington Ship Channel,

                md the upper Anacostia River and Kingman Lake. The enrichment in the Tidal Basin is likely due to

                the large storm sewer that drains the area around the Mall of the Smithsonian and Constitution Ave.

                In the Anacostia River, increased levels of enrichment at AR-4, just downstream of the Washington

                Navy Yard, are proba  bly due to the storm and combined sewers located just above this station. The

                degree to which stations above AR-4 are enriched may be due to multiple sources and a net deposition

                of sediment in this area. From KL-I to AR-4 there are numerous storm and combined sewers that


                drain into this area, while in the Kingman Lake area (KL-l to KI-4), runoff from RFK Stadium and

                the surrounding environment could be a major source of trace metals.

                        One of the goals of this study was to describe the extent and degree of contamination in this

                area. -.Enrichment factors provide a geochemical basis for this description, while a more-subjective

                description is obtained by comparing these data to concentrations in other areas. In this regard, the

                selection of studies can bias the interpretation of the degree of contamination between locations. For

                this reason, only data from the Chesapeake Bay and Delaware Bay will be utilized.

                        The ranges presented in Table 6, fbr the present study are for river and basin sediments only.

                Sewer and outfall sediment samples are not included. Sediment concentrations of Cd, Cu, Hg, and

                Ph in this study are higher than those found in the mainstem, Chesapeake Bay by a factor of 2 to 4,

                dependent on the metal (Table 6). Concentrations of all metals are well below those found in

                Baltimore Harbor and the Schuykill River (Delaware River basin). Compared with the estuarine

                portion of the Potomac River Ci.e., MDE stations MLE2.2, XDA 11, and XEA659; MDE,

                =published data), sediment concentrations of all metals are higher in the Washington, D.C. area,

                reflecting its proximity to the urban runoff source.


                                                                   21








                                                                                                       Velinsky et al.

                                                     Summary and Conclusions

                       The geographic and spatial trends for trace metals in sediments reveal specific areas of

                concern within the Washington, D.C. area. These locations are indicated by increased sediment

                concenwations of trace metals relative to adjacent locations within the study area. In many cases,

                most trace metals exhibited the same spatial concentration gradient with elevated concentrations

                observed in many areas, such as near the Washington Navy Yard (AR-4), at the confluence of Rock

                Creek and the Potomac River (PR-1), and in the upper Washington Ship Channel (WSC-1 to WSC-3).

                Furthermore, concentration gradients between sewer, ourfall, and river sediment samples strongly

                suggest urban runoff as the major source of these contaminants. Ilis is especially noted at station

                AR-4 located just downstream of the Washington Navy Yard, near the South Capitol Street Bridge.

                While the extreme gradient between the sewer, outfall, and river sediments at this location indicates

                urban runoff as a source, past and present activities at the Washington Navy Yard could also

                contribute to the. contamination of the area. 7be net result of all these possible sources are

                substantially higher concentrations of all contaminants at AR-4. The large concentration decrease

                downstream from this area suggests a possible higher source function at AR-4 and/or a greater

                retention of upstream sources (i.e., fine-grain sediments) in this section of the river.

                       7be sediment of the urban Potomac and Anacostia rivers reflect a moderate to highly
                contaminated location with substantial enrichments of sedimentary Pb, Cd, Zn,*and possible Hg. 7be

                source of these metals is most likely urban runoff, however upstream sources and atmospheric

                deposition can not be ruled out. 7be sediment phase or phases that contain these metals indicate a

                potential mobility of these sediment-bound metals if the sediments are disturbed during, fbr example,

                storm events and dredging.




                                                                 22




                                                                 112








                                                                                                    Velinsky et al.



                                                        Admowledgernents

                        We thank Carlton Haywood (ICPRB) and Eli Reinharz (NOAA) fbr technical assistance and

                belp with field sampling. Bob Cuthberson of the Maryland Geological Survey provided the vessel

                ad support during sampling. 7banks to Marilyn Fogel (Geophysical Laboratory) and Greg Cutter

                (Old Dominion University) for the use of laboratory and equipment during part this study. Jeff

                Cornwell (University of Maryland) provided helpful comments on earlier versions of this manuscript.

                lbanks to C. Dalpra for his editorial review and comments. 7bis project was funded by the

                Department of Consumer and Regulatory Affairs, Water Hygiene Branch of the District of Columbia

                with additional support provided by ICPRB. Ile opinions expressed are those of the authors and do

                not represent the opinions or polices of ICPRB.



























                                                               23




                                                               113





                                                        ILiterature Cited                          Velinsky et a].

                Brook, J.M., T.L. Wade, E.L. Atlas, M.C. Kemicutt H, B.J. Presley, R.R. Fay, E.N. Powell, and

                G. Wolff. 1988. Analyses of bivalves and sediments for organic chemicals and trace elements from

                Gulf of Mexico estuaries. Annual Re2grt of the Geochemical and Environmental Research Q-r=,

                Texas A&M University, College Station, Texas. 618 p.



                Chao, T T. and L. Zhou 1983. Extraction techniques for selective dissolution of amorphous iron

                oxides ftorn soils and sediments. Soil Science gf America Journal 47: 225-232.



                Cutter G.C. and TJ. Oarts. 1987. Determination of hydrogen sulfide at nanomolar concentrations

                using photoionization detection. Analylical Chemigta 59: 717-72 1.



                Di Toro, D.M., J.D. Mahony, D.J. Hansen, J.K. Scott, M.B. Hicks, S.M. Mayro and M.S.

                Redmond. 1990. Toxicity of cadmium in sediments: The role of acid-volatile sulfide. Environmental

                Toxicoloa and ChemWa 9: 1487-1502.



                Folk, R.L. 1980. Petrology of Sedimentary Rocks. Hemphill Publishing Co, Austin, Texas 183 p.



                Forstner, U. 1979. Sources and sediment associations of heavy metals in polluted coastal regions, p.

                849-966. In L.H. Ahrens (ed.) Origin and Distribution of the elements, 2nd Symposium, Vol Ul.



                Goldberg, E.D. et al. 1978. A pollution history of the Chesapeake Bay. Geochimica Cosmochimica

                A= 42: 1413-1425.


                                                              24




                                                               114







                                                                                                    Velinsky et al.

                Goldhaber, M.B. and I.R. Kaplan. 1975. The sulfur cycle, p. 569. In E.D. Goldberg (ed.), The Sea,

                 Vol. 5. Marine Chemistry. Wiley and Sons, New York.



                He1z, G.R., S.A. Sinex, K.L. Ferri, and M. Nichols. 1985. Processes controlling Fe, Mn, and Zn in

                 sediments of Northern Chesapeake Bay. Estuarine Coastal Shelf Science 21: 1-16.



                Interstate Commission on the Potomac River Basin (1CPRB). 1988. Anacostia: The Other River.

                 ICPRB Publication 88-1, January 1988, Rockville, MD., 5 p.



                Interstate Commission on the Potomac River Basin (ICPRB). 1990. Sediment Survey of Priority

                 Pollutants in the District of Columbia Waters. Interstate Commission on the Potomac River Basin,

                 ICPRB Publication 90-2, Rockville, MD, 49 p.



                Lion, L.W., R.S. Altman, and J.0. Leckie. 1982. Trace metal adsorption characteristics of estuarine

                 particulate matter: Evaluation of contribution of Fe/Mn oxide and organic surface coatings.

                 Environmental Science and Technolggy 16: 660-666.



                Loring, D.H. 1990. Lithium - a new approach for the granulometric normalization 'of trace metal

                 data. Marine CheMiM 29: 155-168.



                lAoma, S.N. 1993. Bioavailability of trace metals to aquatic organisms- a review. Science of the

                 Total Enviromnen 17: 165-196.






                                                               25




                                                               115







                                                                                                   Velinsky et al.

                Luoma, S.N. and E.A. Jenne. 1976. Estimating bioavailability of sediment-bound trace metals with

                chemical extractants, 343-351 p. In D.D. Hemphill (ed.) Trace Substances in Environmental Health,

                Univ. of Missouri, Columbia, Mo.



                Lyman, W.J., A.E. Glazer, J.H. Ong, and S.F. Coons. 1987. An Overview of Sediment Quality in

                -the United States, Final Report. Rep.# EPA-905/9-8"2, U.S. Environmental Protection Agency,

                Office of Water Regulations and Standards, Washington, D.C.



                Maio, B.A. 1977. Partial extraction of metals from aquatic sediments. AnalZical Chemisia 11: 277-

                282.




                Martin, E.A., J.L. Glenn, C.A. Rice, G. Harrison, E. Gum, and M. Curington. 1981.

                Concentrations of selected trace metals in shallow cores from the tidal Potomac River and estuary.

                U.S.G.S. Open File R=rt 8 1 -1175, Department of the Interior.



                Martin, J-M. and M. Meybeck. 1979. Elemental mass-balance of material carried by world major

                rivers. Marine Chemiga 7: 173-206.



                Martin, J.M., P. Nirel, and A.J. Thomas. 1987. Sequential extraction techniques: Promises and

                problem. Marine ChemiW 22: 313-341.



                National Academy of Sciences (NAS) 1989. Contaminated Marine Sediments-Assessment and

                Rernediation. LCCCN# 89-62967, National Academy Press, Washington, D.C..


                                                              26




                                                                1G_








                                                                                                  Velinsky et al.

                Nadonal Oceanic and Atmospheric Administration (NOAA). 1990. The Potential for Biological

                Effects of Sediment-sorbed contaminants tested in the National Status and Trends Program. NOAA

                Tech, Mem. NOS OMA 52 U.S. Dept. Comm., NOAA, National Ocean Service, Seattle, WA.



                National Oceanic and Atmospheric Administration (NOAA). 1991. National Status and Trends

                Program. Second Summary of Data on Chemical Contaminants in Sediments from the National

                Status and Treads Program. NOAA Tech, Mem. NOS OMA 59, U.S. Dept. Comm., National

                Ocean Service, Rockville, MD.



                Olsen, C.R., N.H. Cutshall, and I.L Larson. 1982. Pollutant-particle associations and dynamics in

                coastal marine environments: A review. Marine Chemiala 11: 501-533.



                Olsenholler, S.M. 1991. Annual Loading Estimates of Urban Toxic Pollutants in the Chesapeake

                Bay Basin. Final Report to U.S. EPA, Chesapeake Bay Program., MetroWlitan Washingnon Council

                of Governments, Washington, D.C..



                Pickering, W.F. 1981. Selective chemical extraction of soil components and bdund metal species.

                CRC Critical Reviews in Analylical Chemista, 233-266 p.



                Pbeiffer, T.H.. 1972. Heavy metals analyses of bottom sediment in the Potomac River estuary. U.S.

                EwAronmental Protection Agency, Tech. Report 49, National TechLiical Information Servic , PB-229

                $02, Springfield, VA., No. 129, 14-25 p.




                                                              27




                                                              117








                                                                                                  Velinsky et al.

              Rapin, F., A. Tessier, P.G.C. Campbell, and R. Carignan. 1986. Potential artifacts in the

               determination of metal partitioning in sediments by a sequential extraction procedure. Environmental

               Science and Technology 20: 836-8Q.



              Reed, J.C. and S.F. Obermeier. 1989. The geology beneath Washington, D.C. - Ile foundations of a

               nation's capitol, p. 27-59. In J.E. Moore and J.A. Jackson (eds.), Geology. Hydrology. and Histoa_

               of thl Washington. D.C, Area. American Geological Institute, Alexandria, VA.



              Scatena, F.N. 1987. Sediment Budgets and Delivery in a Suburban Watershed: Anacostia

               Watershed., Ph.D Dissertation; Johns HoRkins Universi , Baltimore, MD.



              Schropp, SJ., F.G. Lewis, H.L. Windom, J.D. Ryan, F.D. Calder, and L.C. Burney. 1990.
               Interpretad'on of metal concentrations in estuarine sediments of Florida using aluminum as a

               reference element. Estuari 13: 227-235.




              Sinex, S.A. and G.R. He1z. 1981. Regional geochemistry of trace elements in Chesapeake Bay

               sediments. Environmental Geolo   3: 315-323.




              Temier, A., P.G.C. Campbell, and M. Bisson. 1979. Sequential extraction procedure for the

               speciation of particulate trace metals. Anal3aical Che misM 51: 844-851.



              Wedepohl, K.H. 1971. Geochemista. Holt, Rinehart and Winston, Inc., New York. (Translated from

               Geochemie, 1967)



                                                             28




                                                             118








                                                                                                  Velinsky et al.

             Williams, G.P. 1989. Washington, D.C.'s vanishing springs and waterways, p. 76-94. b J.E. Moore

              and J.A. Jackson (eds.), Geology, Hydrology. and Histoa of the Washington, D.C. Area, American

              Geological Institute, Alexandria, VA.



             Windom, H.L., S.J. Schropp, F.D. Calder and others. 1989. Natural trace metal concentrations in

              estuarine and coastal marine sediments of the southeastern United States. Environmental Sci;nce and

              Technology 23: 314-320.



             Young, R.A., D.J.P. Swift, T.L. Clarke, G.R. Harvey, and P.R. Betzer. 1985. Dispersal pathways

              for particle-associated pollutants. Science 229: 431-435.




























                                                             29




                                                             119








                                                                                                              Velinsky et al.

               Table 1. Bulk sediment characteristics for the various study arme.

                 Sta. M.               TOC             SAND             SILT              Clay             AVS

                                         M                                M                 M        (pmol S e-dw)


                 Kinffman LAM


                 KL-1                  4.05              12.8           50.3              36.9                  12.9


                 KL-2                  4.02                3.0          68.8              28.3                  11.8


                 KL-3                  4.06              0.20           67.1              32.7                  12.7


                 KL-4                  4.95              12.9           54.3              32.8                   9.2


                 KL-5                  6.08              11.1           54.6              34.3                   4.8




                 Anacostia Riv


                 KL-5                  6.08              11.1           54.6              34.3                  10.8


                 AR-1                  3.89              13.9           53.4              32.7                   7.5


                 AR-2                  3.99              0.54           63.2              36.2                   7.5


                 AR-3                  2.98              0.53           70.9              28.6                  26.4


                 AR-4                  4.30              14.0           59.2              26.9                  17.0


                 AR-5A                 3.75              0.69           71.4              27.9                   ND


                 AR-6                  3.57              0.86           67.7              31.4                   ND


                 OAR-I                 4.89               9.7           61.6              28.7                   ND


                 OAR-2                 3.44               9.0           68.2              22.8                   ND


                 OAR-3                 2.62              77.7           20.2                2.2                  ND


                 OAR-4                 4.68              10.7           61.3              28.0                   ND


                 OAR-6                 6.08              16.8           52.9              30.3                   ND


                 OAR-RI                0.66              44.9           33.9              21.2                   ND





                                                                     30




                                                                     120









                                                                                                             Velinsky et al.

                Sta. M.                TOC             SAND             SILT             Clay             AVS
                                        M                M               M                 M        (stmol S s'-dw)



                SAR-2                  1.02             78.2            21.4             U.48                   ND


                SAR-3                  0.28             95.6            14.2             0.15                   ND


                SAR-5                  2.50             78.6            19.9               1.5


                SAR-6                  0."              77.4            20.9               1.7




                Washin2ton Shi2 Channel

                Wsc-I                  3.21               1.5           72.2             26.3                   83.0


                WSC-2                  2.89             0.42            $0.2             19.4                   ND


                WSC-3                  3.37             0.33            94.2             15.4                   47.6


                Wsc-5                  2.54             31.5            50.7             17.8                   ND


                WSC-6                  3.74             0.71            69.8             29.5                   ND


                owsc-I                 3.30             15.1            72.9             12.0                   ND


                OWSC-2                 11.1             38.5            51.5             10.0                   ND


                OWSC-3                 2.87             78.6            20.4               1.1                  ND


                owsc-Ri                8.76             39.3            23.3             37.4                   ND


                SWSC-2                 0.37             75.5            24.0             0.55                   ND




                Potomac River


                PR-1                   3.86             21.9            45.8             32.3                   ND


                PR-2                   2.41             13.2            51.9             35.1                   ND


                PR-3                   3.92              9.6            55.0             35.4                   ND


                PR-4A                  4.14              5.9            59.9             34.3                   4.2





                                                                    31




                                                                     121









                                                                                                               Velinsky et al.

                 Sta. M.               TOC              SAND             SILT              Clay            AVS
                                         M                M               M                           (pmol S e-dw)





                 Tidal Basin


                 TB-1                  6.37               2.9            69.9              27.2                   1.0


                 TB-1.5                4.13               1.3            73.6              25.1                   ND


                 TB-2                  3.02              0.69            35.1              35.1                   ND


                 TB-3                  4.70              21.3            46.6              32.1                  20.4


                 TB-4                  3.30              0.45            76.5              23.1                   ND


                 TB-5a                 3.10               1.2            67.7              31.1                   ND


                 TB-6                  3.37              0.63            73.5              25.9                   ND


                 OTB-1-1                 ND               ND              ND                ND                    ND


                 OTB-1-2               3.00              19.4            71.4               9.1                   ND


                 OTB-2                 1.98              $0.1            18.6               1.4                   ND


                 OTB-3                 1.99              $6.6            12.5              0.94                   ND

                 OTB-4                 1.88              81.3            16.5               2.2                   ND


                 OTB-5                 2.34              77.4            21.0               1.6                   ND


                 M-2-1                 9.69              60.7            33.5               5.8                   ND


                 STB-2-2               11.0              49.6            47.9               3.6                   ND




               'Station IDs. starting with the prefix (0) indicate samples that were taken directly in front of

                a wwor outfaU, while M's starting with the prefix (S) indicat samples that were taken in a

                nwer. Stations AR-5., PR-4 and TB-5 wen sampled and analyzed in triplicate and the

                average value is reported. AVS is acid-volatfle sulfur. ND - Not Determined.




                                                                     32




                                                                      122








                                                                                                              Velinsky et al.



               Table 2. Concentrations of trace metals in the sediments of the vaHous study arear.

                 Sta. M.           Cd            Cr         Cu           Fe         Bg           Pb          ZU


                 )Gngm LAkc

                 XL-I               1.53          106         63.8       4.07         0.29         134         348


                 KL-2               2.21          134         92.3       5.04         0.43         194         466


                 KL-3               2.19          118         100        4.73         0.39         177         450


                 KL-4               1.92          106         %.6        4.19         0.46         199         462


                 KL-5               2.01          107         76.1       4.39         0.35         144         418




                 Anscostia River


                 AR-i               1.72          103         75.6       3.91         0.34         139         355


                 AR-2               1.93          118         91.9       4.56         0.29         148         401


                 AR-3               1.%           124         102        4.82         0.37         157         406


                 AR-4               3.18          156         127        4.19         1.04         409         512


                 AR-SA              1.48          108         90.2       5.23         0.36         131         367


                 AR-6               0.92          90.3        63.8       4.82         0.54         83.2        279


                 OAR-I              1.72            11        73.4       4.01         0.30         164         420


                 OAR-2              1.75          116         145        4.25         1.21         195         450

                 OAR-3              0.90          58.0        69.9       1.54         0.72         175         215

                 OAR-4              1.43          109         86.9       4.08         0.30         151         382


                 OAR-6              0.50          74.0        94.7       3.73         1.16         111         208










                                                                     33



                                                                     123








                                                                                                                Velinsky et al.

                ShL ED.            Cd            Cr          Cu           A          Hg           Pb          Zn


                OAR-RI               0.29        31.0          19.9       1.79        0.17         40.0         90.0


                SAR-2                0.79         634          328        3.63        0.18         8140         512


                SAR-3                0.37         163          20.5       2.38        0.01          102         224


                SAR-5                1.68         133          97.4       1.64        2.02          207         271


                SAR-6                0.45         122          47.9       1.43        0.22         96.0         164




                Washington Ship Channel


                WSC-1                1.19        94.3          103        5.06        0.74          183         356


                WSC-2                1.03        95.5          99.9       4.99        0.58          147         332

                WSC-3                1.09        .90.7         92.6       5.24        0.52          126         339

                WSC-5                0.45        51.1          33.4       2.92        0.23         48.3         137


                WSC-6                0.79        96.8          52.6       4.76        0.25         61.9         247

                OWSC-1               1.25        83.0          102        3.33        0.164         163         400

                OWSC-2               3.31         105          251        3.56        0.63          425         1090


                OWSC-3               0.95        63.0          112        1.51        0.20          515         406


                OWSC-RI              3.05         167          348        4.11        0.97         2100         750


                SWSC-2               4.07        44.0.         27.6       1.16        0.05         72.0         200




                Potomac River

                PR-1                 0.99        96.2          59.7       4.45        0.56          128         365

                PR-2                 0.55        66.6          34.2       3.99        0.15         32.0         168

                PR-3                 0.52        63.4          35.6       3.76        0.13         33.9         171

                PR-4A                0.59        69.0          37.8       4.06        0.15         39.0         189





                                                                     34




                                                                      124







                                                                                                             Velinsky etd.

                SUL M.            Cd           Cr           Cu           Fe         49           ft          Zn




                7"idal Basin


                TB-i                1.67         97.4         120        4.89        0.45          204         385


                n-1*5                ND           ND           ND         ND           ND          ND           ND


                TB-2                0.94         91.1         55.1       4.55        0.25        84.5          255


                TB-3                0.74         75.9         44.5       3.89        0.24          109         216


                TB-4                0.97         %.9          66.7       5.09        0.29          104         292


                TB-5A               0.83         87.0         55.3       4.67        0.27        79.3          260


                TB-6                0.93         92.3         59.1       4.88        0.27        91.4          285


                OTB-1-1             0.24         41.0         19.7       0.89        0.07        36.0          62.0


                OTB-1-2             0.83         30.0         47.9       1.67        0.15          120         235


                OTB-2               0.43         28.0         13.7       1.91        o.o6          320         112


                OTB-3               0.89         167          25.9       2.50        0.09        1020          180


                OTII-4              0,94         176          102        2*19        9,22        3630          527


                OTB-5               0.73         149          39.4       2.32        0.13          465         197


                STB-2-1             9.46         3060         1780       7.07        7.03        31300        12Q
                Sn-2-2              2.81         518          ;1 0       1.89        4.96        5020          6M



               -All concentrations am in Ag per gram dry-weight, ex cept for Fe which is %- Station I]Ds- starting with

               the prefix (0) indicate samples that were taken directly in front of a sewer outfall, while ID's starting

              with the prefix (S) indicates samples that were taken in a sewer. Stations AR-5, PR4 and TB-5

                met sampled and analyzed in triplicate, these data am the average. ND - Not Determined.






                                                                    35




                                                                     125








                                                                                                            Velinsky et al.

               Table 3. Ratio of Acid Extractable to Total Sedimentary Metals from

               Selected Statio&.




                ShL ED.                Cd        Cu          Fe       Pb         Zn


                KL-1                 0.94      0.35        0.21     0.80      0.69


                KL-2                 0.91      0.47        0.27     0.98      0.72


                KL-3                 0.99      0.47        0.24     0.90      0.57


                KL-4                 0.91      0.38        0.24     0.78      0.72


                KL-5                 0.79      0.55        0.21     0.79      0.52


                AR-I                 0.88      0.39        0.26     0.91      0.74


                AR-2                 0.92      0.51        0.24     0.93      0.73


                AR-3                 0.92      0.56        0.25     0.94      0.73


                AR-4                 0.74      0.13        0.27     0.85      0.67


                AR-5                 0.87      0.48        0.24     0.84      0.60


                WSC,I                0*92      0*40        0*33     0*96      0*62


                WSC-3                0.77      0.34        0.37     0.88      0.58


                PR4A                 0.77      0.43        0.19     0.67      0.50


                TB-I                 0.70      0.43        0.24     0.70      0.53


                TB-3                 0.72      0.23        0.25     0.59      0.60


                Average              0.84      0.41        0.25     0.93      0.63

                :E SD                0.08      0.11        0.04     0.11      0.08

               'ILL-Kingnian Lake, AR-Anscostia River, WSC-Washington Ship =Cl'

               PR-Potomac River, TB-Tidal Basin.






                                                                    36




                                                                    126








                                                                                                                  Velinsky et al.

                 Table 4. Metal to Iron Ratios used for the Calculation of Enrichment Factors (EFr.


                   Cd       Cr      Cu        Bg      Pb        Zn      Location


                   0.03     20.0    8.5       0.01    4.2       17.0    Continental Crus&


                   ND       18.8    9.2       ND      9.4       25.0    Soile


                   0.01     11.8    3.6       ND      4.4       14.1    St. Mary's County Coastal Deposie


                   0.01     24.0    2.1       ND      3.9       14.5    Ann Arundal County Deposite


                   0.09     9.4     8.1       0.06    NS        NS      Chesapeake Bay Sediments!


                   0.05     23.0    8.1       ND      NS        NS      Core 1314s, Mouth of Potomac River


                   0.04     17.8    6.6       0.04    5.5       17.7    Average


                   0.03     6.0     3.0               2.6       5.1     :k Standard Deviation (lar)



                 'Values am the ratio of total metal (jig g') to total Fe (%). INVedepohl 1971; 'Martin and

                 Meybeck 1979; "Holz et al. 1985; *NOAA 1991; 'Goldberg et al. 1978. ND - No Data;

                 NS - regression between meW and iron was not significant at p <0.05, whereas other

                 metals were significant at p <0.01 (n = 50).

















                                                                        37




                                                                      127








                                                                                                               Velinsky et al.

                Table S. Trace metal esuichment factors OEF) for the sed;-ents of the Washinston, D.C. area'.

                  Sta. ID.                       Cd         Cr         Cu         H9         Pb          zn




                  KL-1                            9.4         1.5        2.4        1.7        6.0        4.8

                  XL-2                           11.0         1.5        2.8        2.1        6.7        5.2

                  KL-3                           11.6         1.4        3.2        2.1        6.8        5.3

                  KL-4                           11.5         1.4        3.5        2.7        8.7        6.2

                  KL-I                           11.5         1.4        2.6        2.0        6.0        5.4




                  Anacostia Riv

                  AR-I                           11.0         1.5        2.9        2.2        6.5        5.1

                  AR-2                           10.6         1.4        3.1        1.6        5.9        4.9

                  AR-3                           10.2         1.4        3.2        1.9        5.9        4.8

                  AR-4                           19.0         2.1        4.6        6.2        17.7       6.9

                  AR-SA                           7.1         1.2        2.6        1.7        4.5        4.0

                  AR-6                            4.8         1.1        2.0        2.8        3.1        3.3




                  Wasbiurtge Shig Channel

                  WSC-1                           5.9         1.0        3.1        3.7        6.6        4.0

                  WSC-2                           5.2         1.1        3.0        2.9        5.3        3.8

                  WSC-3                           5.2         1.0        2.7        2.5        4.4        3.7

                  WSC-5                           3-9         1.0        1.7        1.9        3.0        2-7

                  WSC-6                           4.1         1.0        1.7        1.2        1.4        2.0







                                                                       38




                                                                       128





               Sta. IID.                  Cd        Cr        CU       Hg        Pb        Zu    Velinsky et al.

              -Potomac give


               PR-1                         5.6      1.2       2.0       3.2       5.2       4.6


               PR-2                         3.5      1.0       1.3       1.0       1.5       2.4


               PR-3                         3.5      0.9       1.4       0.9       1.6       2.6


               PR-4A                        3.6      1.0       1.4       0.9       1.8       2.6




               Tidal jas

               TB-1                         8.5      1.1       3.7       2.3       7.6       4.5


               TB-1.5                       ND       ND        ND        ND        ND        ND


               TB-2                         4.6      1.1       1.8       1.4       3.4       3.2


               TB-3                         4.8      1.1       1.7       1.6       5.1       3.1


               TB4                          4.8      1.1       2.0       1.4       3.7       3.2


               TB-5A                        4.5      1.0       1.8       1.4       3.1       3.1


               TB-6                         4.8      1.1       1.8       1.4       3.4       3.3



             sEnrichment factor  (X/Fe).a./(X/1Fe).w,.w, where X is the ft-ace, metal of interest and the

             (X/Fe).w,...j values are taken from Table 4. ND - No data.
















                                                             39




                                                            129








                                                                                                                Velinsky et.al.

                  Table 6. Range of tram metal frorn various studies in the Nd-Atlantic regiort.



                          Cd                 Cr              CU                 Hg               Ph              Zn         Location                Source

                            0.45-3.2          51-155           33-126            0.2-1.0           32-409       137-512     Washington, D-C-        This Studf

                           <I - 650          60-5750         60-2930             0.1-10        130-13890       350 -6040    Baltimore Harbor        Lyman et &1. (1997)

                                  NlY         10-990          10-3000         <0.01 - 0.9       20-19000        30-1400     Schuykill River, PA.    Lyman et &1. (1987)

                             0.2-1.3           39-62           29-43             0.07-0.3           15-73       134-270     Potomac Estuary         MDE' (unpub. data)

                           0.09-0.60          90-237           15-30             0.1-0.2            11-23          42-86    Lower Ches. Day         NOAA (199 1)

                           0.09-0.40          77-647           20-75             0.1-0.4           8.5-27         57-115    Middle Ches. Bay        NOAA (I"l)

       0                   0.2S-0.96         109-280           56-79             0.2-0.5            is-so         93-380    Upper Chas. Bay         NOAA (I"l)


                  Txmcentfations are in ItS per gram dry-weight. 'Only river or basin sediment samples are pfesented for this study. 'ND - No data. 'MDE - Maryland

                  Departnent of the Environment













                                                                                             40








                                                                                                     Velinsky et al.

              list of Figures:

              Figure 1. General study area showing the locations of the Tidal Basin, Washington Ship Channel,

              Kingman Lake and the Potomac and Anacostia rivers. Arrows located around the shoreline indicate

              approximate location of outfall and sewer samples.



              Figure 2. Sediment trace metal distribution: Anacostia River. Transect is from the southern portion of

              Kingman Lake (KL-5) to the confluence of the Anacostia and Potomac rivers and the Washington

              Ship Channel at station PR-4.



              Figure 3. Distribution of selected trace metals in outfall, sewer, and basin sediments of the Tidal

              Basin. Concentrations of Pb are in %.




              Figure 4. Distribution of selected trace metals in outfall, sewer, and channel sediments of the

              Washington Ship Channel.



              Figure 5. Distribution of selected trace metals in outfall, sewer, and river sediments of the Anacostia

              River. Concentrations of Pb are in %.


















                                                               41




                                                               131







                           FORG
                          'I      .70W                                                                     L

                                                                                        District. of               Columbia

                              Vjj;;ZN is
                                                                                       PP.
                                                4
                                                                                   111.@     Tr.

                                                     Room



                          ki
                                                              TVAL'
                                                                                                                                                                        S
                                                                      50
                                                                   4
                                                                            05
                                    N'
                                N                                     03


                                                                         mom,

                     aliq 10 1,    C                                                   4-
                                                                                                                                    Nay
                                                                                                                                                                     P
                                                                                                                              U.S.
                                                                                                                                             2
                                                                                                                        5          ord
                                                                                                 03
                                                                                                  3                                          2
                                                                                                             S.                   A3
                                                                                                                     al A4                   2      11 lh Street Br.
                                                                                                             S.                            A
                                                                                               1A           SL
                                                   ".M                        10
                                                                                                                                    4
                                                                                                                                                3

                                                                                                    5
                                                                                                                  A5
                                                                                                 ;t                                    Key:
                                                                                                           A5
                                                                                                     Greenlee
                                                                                                                                        0 Tidal Basin (TB)
                                                                                                       Point
                                                                                 =3                                                     n Potomac River (PR
                                                              L                           H*m
                                                                                             Point
                                                                             R,                              .!.
                                                                             ..!.                                                       e Washington Ship C
                                                                              1;                 04
                                                                fig
                               4@ @A                                                                                                    A Anacostia River (A
                                                               nj
                                                                                                                                        ci Kingman Lake (KL)

                                                                                                                                                            ouffal
                                                                                         rT1
                                                                                                                                           sewer
                     4
                                                                                                                                     Scale:
                                       X                                                                                                                      meters
                                                                                                                                    0`5M, 1000












                    4.0                                                 200
                           JECdECr[]Cul

                    3.0                                                 150




                   U2.0                                                --100




                    1.0                                                --50




                    0.0                                                 0
                         KL-5 AR-1 AR-2 AR-3  AR4
                                              AR4 AR-5  AR-6WSC-4 PR4
                    2.0 -- IMHgEPb[-]Znl                               -600
                                                                       -500

                    1.5

                                                                        400


                   U1.0                                                --300


                                                                       - - 200 cc

                    0.5.-

                                                                       --100



                    0.0                                                 0
                         KL-5'AR-I'AR-2'AR-3'AR4'AR-5 ARs Wsc

                                          Station ED






                                               133





                 4000  @MPbMUE]Hgj              (17)   10
                                                          E
              ,3000


                                                       6

                 2000




                 1000
                                                       2
                                                         u



                                        L I
                    0          5 6    1 2 3 Rl    2    0
                          Sediment     Outfall  Sewer
               2000 -   Cu   Cr   Zn                 4000

               cc
                1500                                 3000




                1000                                 2000


              u
              PC
              0
                 500                                 1000

              u


                              n jfl
                   0i   l;M?jMI),=IjWIj             1.0
                       1 '2 '3 'S '6 1 '2 '3 RI 2
                          Sediment    Outfall   Sewer

                                 Station ED
                          2







































                                      134








                           3000                                   (3.7%)              10
                                        Pb      Cd     Hg



                           2000
                                                                                      6



                                                                                      4
                        -B1000

                                                                                           cc
                                                                                    ..2


                               0     1 2 3 4             1 2 3 4 6      2 3 5   i6    0
                                         Sediment         Outfall          Sewer
                        2000 -    JECuMCroZnl                           (29M)       4000

                         1500                                                       3000




                      001000                                                       --2000



                     PC
                     r.
                          Soo                                                       1000


                             0 i                                                +-40
                                  1 2 3   4                     i 26'1 2'13 .5
                                     'Sediment        Outfall          Sewer

                                                   Station ED
                                                                              6










                                                          135





                        10000   IN Pb MU[@]Hg 1         (2%)     (8%)         30
                                                               (50)          -.25 S"
                        8000


                                                                              20
                        6000

                                                                             -.15

                        4000
                                                                              10


                        2000


                             0    1 '2 '3 '4 IS '6        33 4 IS   212-2    -0
                                     Sediment          Outfall       Sewer



                        2000                                                  4000
                                 JECuMCr[:]Znl                 C7800) (4SOO)

                        1500                                                  3000




                        1000                                                  2000




                          500


                                       'n in n A     n
                                   limit 11 11EHEII 111 11 1                  0
                            0                5
                                    2 3 4      6     1         5    21- 2.2
                                     Sediment          Outfall        wer
                                               Station ED
                                                       2






























                                                          3











                                                     136

































                                                                                               DATE DUE





















                                                                             GAYLORDINo. 2333                                PR.::!F@ U 5 A


















                                                                                             3 6668 14106 7506