[Federal Register Volume 64, Number 203 (Thursday, October 21, 1999)]
[Notices]
[Pages 56792-56794]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-27466]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Agency for Toxic Substances and Disease Registry
[ATSDR-155]


Notice of the Revised Priority List of Hazardous Substances That 
Will Be the Subject of Toxicological Profiles

AGENCY: Agency for Toxic Substances and Disease Registry (ATSDR), 
Department of Health and Human Services (HHS).

ACTION: Notice.

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SUMMARY: The Comprehensive Environmental Response, Compensation, and 
Liability Act (CERCLA or Superfund), as amended by the Superfund 
Amendments and Reauthorization Act (SARA), requires that ATSDR and the 
Environmental Protection Agency (EPA) revise the Priority List of 
Hazardous Substances. This list includes substances most commonly found 
at facilities on the CERCLA National Priorities List (NPL) which have 
been determined to be of greatest concern to public health at or around 
these NPL hazardous waste sites. This announcement provides notice that 
the agencies have developed and are making available a revised CERCLA 
Priority List of 275 Hazardous Substances, based on the most recent 
information available to ATSDR and EPA. Each substance on the priority 
list is a candidate to become the subject of a toxicological profile 
prepared by ATSDR and subsequently a candidate for the identification 
of priority data needs.
    In addition to the Priority List of Hazardous Substances, ATSDR has 
developed a Completed Exposure Pathway Site Count Report. This report 
lists the number of sites or events with ATSDR activities where a 
substance has been found in a completed exposure pathway (CEP). This 
report is included in the Support Document of the Priority List.

ADDRESSES: Requests for a copy of the report, the 1999 CERCLA Priority 
List of Hazardous Substances That Will Be The Subject of Toxicological 
Profiles and Support Document, including the CEP report, should bear 
the docket control number ATSDR-155, and should be submitted to: ATSDR 
Information Center, Division of Toxicology, Mail Stop E-29, 1600 
Clifton Rd., NE, Atlanta, GA 30333. Requests must be in writing.
    Electronic Availability: The 1999 Priority List of Hazardous 
Substances will be posted on ATSDR's World-Wide Web server on the 
Internet located at http://www.atsdr.cdc.gov/99list.html. The priority 
list will also be posted on the Federal Bulletin Board on or near the 
day of publication of this notice in the Federal Register. The Federal 
Bulletin Board can be accessed via the Internet at http://
fedbbs.access.gpo.gov/libs/tsd__frc.htm. This file is available in 
WordPerfect, Dbase, and ASCII formats.
    This is an informational notice only, and comments are not being 
solicited at this time. However, any comments received will be 
considered for inclusion in the next revision of the list and placed in 
a publicly accessible docket; therefore, please do not submit 
confidential business or other confidential information.

FOR FURTHER INFORMATION CONTACT: ATSDR, Division of Toxicology, 
Emergency Response and Scientific Assessment Branch, 1600 Clifton Road 
NE, Mail Stop E-29, Atlanta, GA 30333, telephone 888-442-8737.

SUPPLEMENTARY INFORMATION: CERCLA establishes certain requirements for 
ATSDR and EPA with regard to hazardous substances that are most 
commonly found at facilities on the CERCLA NPL. Section 104(i)(2) of 
CERCLA, as amended (42 U.S.C. 9604(i)(2)), required that the two 
agencies prepare a list, in order of priority, of at least 100 
hazardous substances that are most commonly found at facilities on the 
NPL and which, in their sole discretion, have been determined to pose 
the most significant potential threat to human health (see 52 FR 12866, 
April 17, 1987). CERCLA also required the

[[Page 56793]]

agencies to revise the priority list to include 100 or more additional 
hazardous substances (see 53 FR 41280, October 20, 1988), and to 
include at least 25 additional hazardous substances in each of the 
three successive years following the 1988 revision (see 54 FR 43619, 
October 26, 1989; 55 FR 42067, October 17, 1990; 56 FR 52166, October 
17, 1991). CERCLA also requires that ATSDR and EPA shall, at least 
annually thereafter, revise the list to include additional hazardous 
substances that have been determined to pose the most significant 
potential threat to human health. In 1995, the agencies altered the 
publication schedule of the priority list by moving to a 2-year 
publication schedule, reflecting the stability of this listing activity 
(60 FR 16478, March 30, 1995). As a result, the priority list is now on 
a 2-year publication schedule with a yearly informal review and 
revision. Each substance on the CERCLA Priority List of Hazardous 
Substances is a candidate to become the subject of a toxicological 
profile prepared by ATSDR and subsequently a candidate for the 
identification of priority data needs.
    The initial priority lists of hazardous substances (1987-1990) were 
based on the most comprehensive and relevant information available when 
the lists were developed. More comprehensive sources of information on 
the frequency of occurrence and the potential for human exposure to 
substances at NPL sites became available for use in the 1991 priority 
list with the development of ATSDR's HazDat database. Utilizing this 
database, a revised approach and algorithm for ranking substances was 
developed in 1991, and a notice announcing the intention of ATSDR and 
EPA to revise and rerank the Priority List of Hazardous Substances was 
published on June 27, 1991 (56 FR 29485). The subsequent 1991 Priority 
List and revised approach used for its compilation was summarized in 
the ``Revised Priority List of Hazardous Substances'' Federal Register 
notice published October 17, 1991 (56 FR 52166). The same approach and 
the same basic algorithm have been used in all subsequent activities, 
including the 1999 listing activity. The algorithm used in ranking 
hazardous substances on the priority list consists of three criteria, 
which are combined to result in the total score. The three criteria 
are: frequency of occurrence at NPL sites; toxicity; and potential for 
human exposure.
    Since HazDat is a dynamic database with ongoing data collection, 
additional information from the HazDat database became available for 
the 1999 listing activity. This additional information has been entered 
into HazDat since the development of the 1997 Priority List of 
Hazardous Substances. The site-specific information from HazDat that is 
used in the listing activity has been collected from ATSDR public 
health assessments, health consultations, and from site file data 
packages that are used to develop these public health assessments. The 
new information may include more recent NPL frequency of occurrence 
data, additional concentration data, and more information on exposure 
to substances at NPL sites. With these additional data, 17 substances 
have been replaced on the list of 275 substances. Of the 17 replacement 
substances, 12 are new candidate substances, and 5 are substances that 
were previously under consideration. These replacement substances and 
changes in the order of substances appearing on the CERCLA Priority 
List of Hazardous Substances will be reflected in the program 
activities that rely on the list for future direction. These changes 
reflect the dynamic nature of scientific data on substances present at 
NPL hazardous waste sites.
    The 1999 Priority List of Hazardous Substances includes 275 
substances that have been determined to be of greatest concern to 
public health based on the criteria of CERCLA Section 104(i)(2) (42 
U.S.C. 9604(i)(2)). A total of 815 candidate substances have been 
analyzed and ranked with the current algorithm. Of these candidates, 
the 275 substances on the priority list may become the subject of 
toxicological profiles in the future. The top 25 substances on the 1999 
Priority List of Hazardous Substances are listed below.

------------------------------------------------------------------------
              Rank                            Substance name
------------------------------------------------------------------------
1..............................  ARSENIC.
2..............................  LEAD.
3..............................  MERCURY.
4..............................  VINYL CHLORIDE.
5..............................  BENZENE.
6..............................  POLYCHLORINATED BIPHENYLS.
7..............................  CADMIUM.
8..............................  BENZO(A)PYRENE.
9..............................  POLYCYCLIC AROMATIC HYDROCARBONS.
10.............................  BENZO(B)FLUORANTHENE.
11.............................  CHLOROFORM.
12.............................  DDT, P,P'-.
13.............................  AROCLOR 1260.
14.............................  AROCLOR 1254.
15.............................  TRICHLOROETHYLENE.
16.............................  CHROMIUM, HEXAVALENT.
17.............................  DIBENZO(A,H)ANTHRACENE.
18.............................  DIELDRIN.
19.............................  HEXACHLOROBUTADIENE.
20.............................  DDE, P,P'-.
21.............................  CREOSOTE.
22.............................  CHLORDANE.
23.............................  BENZIDINE.
24.............................  ALDRIN.
25.............................  AROCLOR 1248.
------------------------------------------------------------------------

    ATSDR and EPA intend to publish the next revised list of hazardous 
substances in two years, with an informal review and revision performed 
in one year. These revisions will reflect changes and improvements in 
data collection and availability. Additional information on the 
existing methodology used in the development of the CERCLA Priority 
List of Hazardous Substances can be found in the Support Document to 
the List and in the Federal Register notices mentioned previously.
    In addition to the revised priority list, ATSDR is also releasing a 
Completed Exposure Pathway Site Count Report. A completed exposure 
pathway (CEP) is an exposure pathway that links a contaminant source to 
a receptor population. The CEP ranking is very similar to a sub-
component of the potential-for-human-exposure component of the listing 
algorithm. The CEP ranking is based on a site frequency count, and thus 
lists the number of sites at which a substance has been found in a CEP. 
ATSDR's HazDat database contains this information which is derived from 
ATSDR public health assessments and health consultations. Because 
exposure to hazardous substances is of significant concern, ATSDR has 
been tabulating the substances to which people have been exposed at 
hazardous waste sites. Recently much interest has been focused on this 
tabulation. Therefore, ATSDR is publishing this CEP report along with 
the CERCLA Priority List of Hazardous Substances. Since this CEP report 
focuses on documented exposure, it provides an important prioritization 
based on substances to which people are exposed.
    The substances on the CEP report are similar to the substances on 
the CERCLA Priority List of Hazardous Substances. However, there are 
some substances that are on the CEP report, because they are frequently 
found in completed exposure pathways, but are not on the CERCLA 
Priority List because they have a very low toxicity (e.g., sodium). 
Since the CERCLA Priority List incorporates three different components 
(toxicity, frequency of occurrence, and potential for human exposure) 
to determine its priority substances, substances with very low toxicity 
are not on the CERCLA Priority List and consequently are not the 
subject of toxicological profiles. Of the 100

[[Page 56794]]

substances on the CEP report, the 25 substances found at the most 
number of sites in a CEP are presented below.

------------------------------------------------------------------------
                                          Number of sites with substance
                                                     in a CEP
             Substance name              -------------------------------
                                             All sites       NPL sites
------------------------------------------------------------------------
LEAD....................................             298             206
TRICHLOROETHYLENE.......................             277             239
ARSENIC.................................             215             147
TETRACHLOROETHYLENE.....................             206             167
BENZENE.................................             149             116
CADMIUM.................................             148             105
CHROMIUM................................             146             102
POLYCHLORINATED BIPHENYLS...............             130              96
1,1,1-TRICHLOROETHANE...................             116              97
ZINC....................................             116              75
MANGANESE...............................             116              73
MERCURY.................................             115              74
COPPER..................................             101              61
VOLATILE ORGANIC COMPOUNDS, UNSPECIFIED.              99              73
CHLOROFORM..............................              98              81
1,1-DICHLOROETHENE......................              94              87
METHYLENE CHLORIDE......................              93              69
TOLUENE.................................              86              60
NICKEL..................................              84              59
BARIUM..................................              82              52
VINYL CHLORIDE..........................              81              75
1,1-DICHLOROETHANE......................              80              72
1,2-DICHLOROETHANE......................              77              66
BENZO(A)PYRENE..........................              77              46
ANTIMONY................................              74              50
------------------------------------------------------------------------
Note: Sorted by the All Sites column.
ALL Sites = all sites with ATSDR activities; NPL Sites = current and
  former sites on the National Priorities List, as mandated.

    Dated: October 15, 1999.
Georgi Jones,
Director, Office of Policy and External Affairs, Agency for Toxic 
Substances and Disease Registry.
[FR Doc. 99-27466 Filed 10-20-99; 8:45 am]
BILLING CODE 4163-70-P