[Federal Register Volume 67, Number 21 (Thursday, January 31, 2002)]
[Notices]
[Pages 4836-4854]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-2421]



[[Page 4835]]

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Part IV





Department of Health and Human Services





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Agency for Toxic Substances and Disease Registry



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Update on the Status of the Superfund Substance-Specific Applied 
Research Program; Notice

  Federal Register / Vol. 67, No. 21 / Thursday, January 31, 2002 / 
Notices  

[[Page 4836]]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Agency for Toxic Substances and Disease Registry

[ATSDR-178]


Update on the Status of the Superfund Substance-Specific Applied 
Research Program

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

ACTION: Notice.

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SUMMARY: This Notice provides the status of ATSDR's Superfund-mandated 
Substance-Specific Applied Research Program (SSARP) which was last 
updated in a Federal Register notice in 1999 (64 FR 2760). Authorized 
by the Comprehensive Environmental Response, Compensation, and 
Liability Act of 1980 (CERCLA, also known as the Superfund statute), as 
amended by the Superfund Amendments and Reauthorization Act of 1986 
(SARA) 42 U.S.C. 9604 (i), this research program was initiated on 
October 17, 1991. At that time, a list of priority data needs for 38 
priority hazardous substances frequently found at waste sites was 
announced in the Federal Register (56 FR 52178). The list was 
subsequently revised based on public comments and published in final 
form on November 16, 1992 (57 FR 54150).
    The 38 substances, each of which is found on ATSDR's Priority List 
of Hazardous Substances (66 FR 54014, October 25, 2001), are aldrin/
dieldrin, arsenic, benzene, beryllium, cadmium, carbon tetrachloride, 
chloroethane, chloroform, chromium, cyanide, p,p'-DDT,DDE,DDD, di(2-
ethylhexyl) phthalate, lead, mercury, methylene chloride, nickel, 
polychlorinated biphenyl compounds (PCBs), polycyclic aromatic 
hydrocarbons (PAHs--includes 15 substances), selenium, 
tetrachloroethylene, toluene, trichloroethylene, vinyl chloride, and 
zinc.
    On July 30, 1997, priority data needs for 12 additional hazardous 
substances frequently found at waste sites were determined and 
announced in the Federal Register (62 FR 40820). The 12 substances, 
each of which is included in ATSDR's Priority List of Hazardous 
Substances, are chlordane, 1,2-dibromo-3-chloropropane, di-n-butyl 
phthalate, disulfoton, endrin (includes endrin aldehyde), endosulfan 
(alpha-, beta-, and endosulfan sulfate), heptachlor (includes 
heptachlor epoxide), hexachlorobutadiene, hexachlorocyclohexane (alpha-
, beta-, delta- and gamma-), manganese, methoxychlor, and toxaphene.
    Recently, priority data needs for 10 additional hazardous 
substances frequently found at waste sites were determined and 
announced in the Federal Register (66 FR 42659). The 10 substances, 
each of which is included in ATSDR's Priority List of Hazardous 
Substances, are asbestos, benzidine, chlorinated dibenzo-p-dioxins, 
1,2-dibromoethane, 1,2-dichloroethane, 1,1-dichloroethane, 
ethylbenzene, pentachlorophenol, 1,1,2,2-tetrachloroethane, and total 
xylenes. ATSDR invited the public to comment on the priority data needs 
for these substances during a period of 90 days. ATSDR is responding to 
the comments, and a final list of priority data needs will be published 
in the Federal Register in the near future.
    To date, 190 priority data needs have been identified for the first 
50 hazardous substances (Table 1). ATSDR fills these data needs through 
U.S. Environmental Protection Agency (EPA) regulatory mechanisms (test 
rules), private-sector voluntarism, and the direct use of CERCLA funds. 
Additional data needs are being addressed through collaboration with 
the National Toxicology Program (NTP), by ATSDR's Great Lakes Human 
Health Effects Research Program, and other agency programs. Currently, 
101 priority data needs associated with the first 50 substances are 
being addressed via these mechanisms, and 62 priority data needs have 
been filled. Priority data needs documents describing ATSDR's rationale 
for prioritizing research needs for each substance are available. See 
ADDRESSES section of this Notice.
    This Notice also serves as a continuous call for voluntary research 
proposals. Private-sector organizations may volunteer to conduct 
research to address specific priority data needs identified in this 
Notice by indicating their interest through submission of a letter of 
intent to ATSDR (see ADDRESSES section of this Notice). A Tri-Agency 
Superfund Applied Research Committee (TASARC) composed of scientists 
from ATSDR, NTP, and the EPA, will review all proposed voluntary 
research efforts.

DATES: ATSDR provides updates on the status of its Substance-Specific 
Applied Research Program approximately every 3 years. ATSDR considers 
the voluntary research effort to be important to the continuing 
implementation of the SSARP. Therefore, the agency strongly encourages 
private-sector organizations to volunteer at any time to conduct 
research to fill data needs until ATSDR announces that other research 
mechanisms are in place to address those specific data needs.

ADDRESSES: Private-sector organizations interested in volunteering to 
conduct research can write to Dr. William Cibulas, Chief, Research 
Implementation Branch, Division of Toxicology, ATSDR, 1600 Clifton 
Road, NE., Mailstop E-29, Atlanta, Georgia 30333, e-mail: 
[email protected]. Information about pertinent ongoing or completed 
research that may fill priority data needs cited in this Notice should 
be similarly addressed.
    Other Requirements: Projects that involve the collection of 
information from 10 or more individuals and funded by cooperative 
agreement will be subject to review by the Office of Management and 
Budget (OMB) under the Paperwork Reduction Act.

FOR FURTHER INFORMATION CONTACT: Dr. William Cibulas, Chief, Research 
Implementation Branch, Division of Toxicology, ATSDR, 1600 Clifton 
Road, NE., Mailstop E-29, Atlanta, Georgia 30333, telephone: (404) 498-
0715, fax: (404) 498-0092. This notice will also be available on 
ATSDR's website at 
http://www.atsdr.cdc.gov or you may call the ATSDR Information Center 
at 1-888-422-8737.

SUPPLEMENTARY INFORMATION:

Background

    CERCLA as amended by SARA (42 U.S.C. 9604(i)) requires that ATSDR 
(1) jointly with the EPA, develop and prioritize a list of hazardous 
substances found at National Priorities List (NPL) sites, (2) prepare 
toxicological profiles for these substances, and (3) assure the 
initiation of a research program to address identified data needs 
associated with the substances. Before starting such a program, ATSDR 
will consider recommendations of the Interagency Testing Committee on 
the type of research that should be done. This committee was 
established under Section 4(e) of the Toxic Substances Control Act of 
1976 [15 U.S.C. 2604(e)](TSCA).
    The major goals of the ATSDR SSARP are (1) to address the 
substance-specific information needs of the public and scientific 
community, and (2) to supply information necessary to improve the 
database used to conduct comprehensive public health assessments of 
populations living near hazardous waste sites. We anticipate that the 
information will help to establish linkages between levels of 
contaminants in the environment and levels in human tissue and organs

[[Page 4837]]

associated with adverse health effects. Once such links have been 
established, strategies to mitigate potentially harmful exposures can 
be developed. This program will also provide data that can be 
generalized to other substances or areas of science, including risk 
assessment of chemicals, thus creating a scientific information base 
for addressing a broader range of data needs.
    ATSDR encourages the use of in vitro assessment methods and other 
innovative tools for filling priority data needs. For example, the 
agency believes that physiologically based pharmacokinetic (PBPK) 
modeling could serve as a valuable tool in predicting across route 
similarities (or differences) in toxicological responses to hazardous 
substances. Therefore, on a case-by-case basis, a priority data need 
can be filled using existing data and modeling. In addition, ATSDR is a 
member of NTP's Interagency Coordinating Committee on the Validation of 
Alternative Methods (ICCVAM) and supports development, validation, and 
acceptance of alternative toxicological test methods that reduce, 
refine, and replace the use of animals, as appropriate.
    CERCLA section 104(i)(5)(D) states that it is the sense of Congress 
that the costs for conducting this research program ``be borne by the 
manufacturers and processors of the hazardous substance in question,'' 
as required in TSCA and the Federal Insecticide, Fungicide, and 
Rodenticide Act of 1972 (7 U.S.C. 136 et seq.) (FIFRA), or by cost 
recovery from responsible parties under CERCLA. To execute this 
statutory intent, ATSDR developed a plan whereby parts of the SSARP are 
being conducted via the regulatory mechanisms referenced (TSCA/FIFRA), 
private-sector voluntarism, and the direct use of CERCLA funds.
    The TASARC, composed of scientists from ATSDR, NTP, and EPA, has 
been set up to:
    (1) Advise ATSDR on the assignment of priorities for mechanisms to 
address data needs,
    (2) Coordinate knowledge of research activities to avoid 
duplication of research in other programs and under other authorities,
    (3) Advise ATSDR on issues of science related to substance-specific 
data needs, and
    (4) Maintain a scheduled forum that provides an overall review of 
the ATSDR SSARP.
    TASARC has met 10 times since the initiation of the SSARP. It has 
guided referral of data needs to EPA and the associated development of 
test rules through TSCA. In addition, it has endorsed the proposals of 
several private-sector organizations to conduct voluntary research. 
Furthermore, TASARC has become a forum for other federal agencies to 
bring forth their research agendas. For example, it has coordinated 
research efforts on hazardous pollutants with the Office of Air and 
Radiation, EPA. TASARC has developed testing guidelines for 
immunotoxicity; and has endorsed the use of decision-support 
methodologies such as physiologically based pharmacokinetic (PBPK) 
modeling and benchmark-dose modeling, where appropriate.
    Additional data needs are being addressed through collaborative 
research efforts with NTP, by ATSDR's Great Lakes Human Health Effects 
Research Program, and other agency programs. To date, 101 priority data 
needs associated with the first 50 substances (Table 1) are being 
addressed via these mechanisms.

Criteria for Evaluating Status of Priority Data Needs

    To update the activities covered under the SSARP, criteria for 
evaluating the status of the priority data needs were developed. Based 
on these criteria and the review of the current literature, a priority 
data need can be filled, or unchanged. In the event a priority data 
need is considered filled, it does not necessarily mean that the study 
has been completed and that ATSDR has accepted the data. It does, 
however, indicate that the agency no longer considers it a priority to 
initiate additional studies at this time.
    The criteria for evaluating the status of the priority data needs 
are described below.

General Criteria

    A priority data need is filled:
     If it has been referred to one of the implementation 
mechanisms and research has been initiated, or
     If an updated ATSDR toxicological profile or other recent 
review document contains relevant new (peer-reviewed and publicly 
available) studies since the finalization of the priority data needs 
document; and it is generally agreed that a priority data need no 
longer exists.
    A priority data need remains unchanged:
     If no mechanism or information has been identified to 
address the priority data need, or
     If the priority data need is included in the ATSDR/EPA 
test rule under development, or is associated with a pilot substance in 
EPA's Voluntary Children's Chemical Evaluation Program.

Specific Criteria

    Since the 1999 SSARP update in the Federal Register, ATSDR has 
developed specific criteria for two categories of data needs described 
below.
     Epidemiologic studies--A priority data need is filled if 
multiple new studies assessing key health end points are available in 
ATSDR's updated toxicological profile and/or ongoing studies have been 
identified, e.g., human health studies supported by ATSDR's Great Lakes 
Human Health Effects Research Program or the Minority Health 
Professions Foundation Research Program. In some cases, ATSDR indicates 
that it will continue to evaluate new data as they become available to 
determine whether additional studies are needed.
     Exposure levels in humans--A priority data need is filled 
if (a) there are current and adequate biomonitoring data for exposed 
populations associated with health effects (from published or ongoing 
studies), or (b) there are reference range data (e.g., National Health 
and Nutrition Examination Survey (NHANES)) or generally agreed upon 
background population levels. In the latter case, ATSDR acknowledges 
that reference concentration data can support exposure and health 
assessments at waste sites, but the agency also continues to recognize 
the importance of collecting additional data on uniquely exposed 
populations at waste sites.
    It should be noted that the status of the priority data needs may 
change in future updates of the SSARP as new information becomes 
available. Further, during the literature review, new studies may be 
identified suggesting other effects of concern, such as those related 
to endocrine disruptors and children's health, which have not been 
included in the original list of priority data needs. In such cases, 
additional priority data needs may be added to the research agenda. For 
example, for both tetrachloroethylene and trichloroethylene, the 
priority data need for developmental neurotoxicity study is now listed 
separately from the priority data need for one-species developmental 
toxicity (see Table 1). Therefore, the total number of priority data 
needs changed accordingly, i.e., from a total of 188 reported in the 
Federal Register notice in 1999 (64 FR 2760) to 190 in the current 
update notice. Also, research needs previously considered filled might 
be reassigned as priority data needs, e.g., if a previously derived 
Minimal Risk Level (MRL), a

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health guidance value, was withdrawn from the updated ATSDR 
toxicological profile. Finally, a priority data need previously 
associated with an implementation mechanism, may no longer be addressed 
via that mechanism (or any other mechanism) if the study being 
conducted to fill the specific priority data need is discontinued.
    Based on the above criteria, 62 priority data needs have been 
filled.

Update of Activities in the SSARP

    An update of the activities associated with the mechanisms for 
implementing the ATSDR Substance-Specific Applied Research Program 
(SSARP) is discussed below. Publications and reports of research 
completed under the various implementation mechanisms are available by 
writing to ATSDR (see ADDRESSES section of this Notice).

A. TSCA/FIFRA

    In developing and implementing the SSARP, ATSDR, NTP, and EPA have 
identified a subset of priority data needs for substances of mutual 
interest to the federal programs. These data needs are being addressed 
through a program of toxicologic testing under TSCA according to 
established procedures and guidelines. On several occasions when ATSDR 
identified priority data needs for oral exposure, other agencies needed 
inhalation data. In response, ATSDR is considering proposals to conduct 
inhalation studies in conjunction with physiologically based 
pharmacokinetic (PBPK) studies in lieu of oral studies. ATSDR expects 
that inhalation data derived from these studies can be used with PBPK 
modeling to address its oral toxicity data needs. Currently, an EPA/
ATSDR test rule, under development, includes eight ATSDR substances, 
i.e., benzene, chloroethane, cyanide (hydrogen cyanide and sodium 
cyanide), methylene chloride, tetrachloroethylene, toluene and 
trichloroethylene, and addresses 18 ATSDR priority data needs (Table 
2). The test rule is presently undergoing ATSDR and EPA final review. 
We anticipate it will be available for public comment in the near 
future.
    TASARC has established an interagency task force on metals and has 
conducted a survey to assess federal agencies' needs for testing 
metals. Currently, the task force has agreed to examine at least seven 
metals included in the ATSDR's SSARP (arsenic, beryllium, chromium, 
manganese, mercury, nickel, and selenium, associated with 22 priority 
data needs) (Table 2). The EPA will solicit testing proposals for these 
metals and pursue test rule development for these metals at a later 
date.

B. Private-Sector Voluntarism

    On February 7, 1992, as part of the Substance-Specific Applied 
Research Program (SSARP), ATSDR announced a set of proposed procedures 
for conducting voluntary research (57 FR 4758). Revisions based on 
public comments were published on November 16, 1992 (57 FR 54160). 
Private-sector organizations were encouraged to volunteer to conduct 
research to fill specific priority data needs at no expense to ATSDR.
    To date, ATSDR has established agreements with the American 
Chemistry Council (ACC) [formerly the Chemical Manufacturers 
Association (CMA)], the General Electric Company (GE), and the 
Halogenated Solvents Industry Alliance, Inc. (HSIA) to conduct 
substance-specific research (Table 2). Through the voluntary research 
efforts of these organizations, at least 16 research needs for 
polychlorinated biphenyl compounds [PCBs], methylene chloride, 
tetrachloroethylene, trichloroethylene, and vinyl chloride are being 
addressed (Table 2).
American Chemistry Council (ACC) Formerly the Chemical Manufacturers 
Association (CMA)
    In 1996, ATSDR entered into a memorandum of understanding (MOU) 
with ACC covering two studies, ``Vinyl chloride: Combined inhalation 
two-generation reproduction and developmental toxicity study in CD 
rats.'' In November 2000, ATSDR accepted the final reports of the 
studies.
General Electric Company (GE)
    In 1995, ATSDR entered into an MOU with SSARP covering two studies 
on PCBs: (1) ``An assessment of the chronic toxicity and oncogenicity 
of Aroclors 1016, 1242, 1254, and 1260 administered in diet to rats,'' 
including ``PCB congener analyses,'' and (2) ``Metabolite detection as 
a tool for determining naturally occurring aerobic PCB 
biodegradation.'' While the above studies do not address ATSDR's 
priority data needs for PCBs, they do address other agency research 
needs for these substances.
    The agency accepted the final report for the chronic toxicity and 
oncogenicity of the four aroclors in October 1997,and the final report 
for the aerobic biodegradation study in July 1999.
Halogenated Solvents Industry Alliance (HSIA)
    In 1995, ATSDR entered into an MOU with HSIA covering studies to 
address three priority data needs for methylene chloride. The studies, 
``Addressing priority data needs for methylene chloride with 
physiologically based pharmacokinetic modeling,'' evaluated acute- and 
subchronic-duration toxicity and developmental toxicity via oral 
exposure. The data were obtained using physiologically based 
pharmacokinetic modeling. The final report for these studies was 
accepted by the agency in February 1997.
    In September 1999, HSIA entered into a second MOU with ATSDR to 
conduct a study, ``Methylene chloride: 28 day inhalation toxicity study 
in the rat to assess potential immunotoxicity.'' The agency accepted 
the final report for the study in November 2000. HSIA is in the process 
of obtaining oral data from the inhalation study using PBPK modeling. 
This is because ATSDR has determined ingestion of contaminated 
environmental media to be the primary exposure route at hazardous waste 
sites. HSIA intends to conduct similar immunotoxicity studies for 
tetrachloroethylene and trichloroethylene.
    In February 2000, ATSDR signed a third MOU with HSIA, which 
conducted a study, ``Trichloroethylene: Inhalation Developmental 
Toxicity Study in CD Rats.'' The agency accepted the final report of 
the study in September 2001. As in the case of the methylene chloride 
immunotoxicity study described above, HSIA intends to obtain 
developmental toxicity data for oral exposure using PBPK modeling. 
Also, HSIA plans to perform similar developmental toxicity studies for 
tetrachloroethylene. Finally, ATSDR and HSIA are continuing discussion 
to address additional priority data needs for trichloroethylene and 
tetrachloroethylene in conjunction with EPA's pilot studies for its 
Voluntary Children's Chemical Evaluation Program.
    In addition to the substance-specific MOUs described above, in 
March 2001, ATSDR also signed an MOU with the Electric Power Research 
Institute, Inc. (EPRI) on ``Verification of Techniques for Assessing 
the Effects of Neurotoxicants on Neurodevelopment in Children.'' The 
objective of the study is to validate a battery of neurodevelopmental 
tests for use in assessing the effects of prenatal or postnatal 
exposure to developmental neurotoxicants. The study includes an 
evaluation of a broad spectrum of

[[Page 4839]]

functions; therefore, the validation of these tests will be useful for 
further assessing the developmental neurotoxicity of some of the ATSDR 
priority substances such as the PCBs, methylmercury, and lead. In 
addition to the private sector support (EPRI), ATSDR is coordinating a 
federal effort (via interagency agreements with EPA, Food and Drug 
Administration [FDA] and NIEHS) to support the study.

C. CERCLA-Funded Research (Minority Health Professions Foundation 
Research Program)

    During FY 1992, ATSDR announced a $4 million cooperative agreement 
program with the Minority Health Professions Foundation (MHPF) to 
support substance-specific investigations. A not-for-profit Internal 
Revenue Code 501(c)(3) organization, the MHPF comprises 11 minority 
health professions schools. Its primary mission is to research health 
problems that disproportionately affect poor and minority citizens. The 
purpose of this cooperative agreement is to address substance-specific 
data needs for priority hazardous substances identified by ATSDR. In 
addition, this agreement strengthens the environmental health research 
opportunities for scientists and students at MHPF member institutions 
and enhances existing disciplinary capacities to conduct research in 
toxicology and environmental health.
    In the first 5-year project period that concluded during FY 1997, 
nine priority data needs for 21 priority hazardous substances and 22 
other research needs for these and other substances were addressed. The 
MHPF has developed a report, ``Environmental Health and Toxicology 
Research Program: Meeting Environmental Health Challenges Through 
Research, Education, and Service,'' that describes the research 
findings and other successes from the first 5 years of the program. New 
research initiated in the second 5-year project period includes studies 
to address 10 additional priority data needs for chlordane, 1,2-
dibromo-3-chloropropane, di-n-butyl phthalate, lead, manganese, the 
polycyclic aromatic hydrocarbons (PAHs), zinc, and eight other research 
needs.
    To date, the MHPF activities have resulted in the publication of 50 
manuscripts in peer-reviewed journals. The institutions receiving 
awards and their current respective research projects that fill 
identified research needs are listed in Table 2.

D. National Toxicology Program (NTP)

    Section 104(i)(5) of CERCLA directs the administrator of ATSDR (in 
consultation with the administrator of EPA and agencies and programs of 
the Public Health Service) to assess whether adequate information on 
the health effects of priority hazardous substances found at NPL sites 
is available. Where adequate information is not available, ATSDR, in 
cooperation with the National Toxicology Program (NTP), is required to 
assure the initiation of a program of research designed to determine 
these health effects (and techniques for developing methods to 
determine such health effects).
    ATSDR has been collaborating with NTP to address priority data 
needs of mutual interest, including (1) di-n-butyl phthalate: dose-
response data in animals for acute-duration exposure via oral exposure 
route, (2) carbon tetrachloride: immunotoxicology study via oral 
exposure, and (3) heptachlor: reproductive toxicity study via oral 
exposure (Table 2).

E. Great Lakes Human Health Effects Research Program

    Some of the priority data needs identified in the SSARP have been 
independently identified as research needs through the ATSDR Great 
Lakes Human Health Effects Research Program, a separate research 
program.
    In support of the Great Lakes Critical Programs Act of 1990, ATSDR 
announced in FY 1992 the availability of $2 million for a grant program 
to conduct research on the potential for short- and long-term adverse 
health effects from consumption of contaminated fish from the Great 
Lakes basin. Research undertaken through this program is intended to 
build on and amplify the results of past and ongoing fish consumption 
research in the Great Lakes basin. The ATSDR-supported research 
projects focus on known high-risk populations to define further the 
human health consequences of exposure to persistent toxic substances 
(PTSs) identified in the Great Lakes basin. These at-risk populations 
include sport anglers; African Americans, Asians and other non-English 
speaking populations; pregnant women; fetuses, nursing infants, and 
children of mothers who consume contaminated Great Lakes sport fish; 
the elderly, and the urban poor. To date, the research activities of 
the ATSDR Great Lakes research program have resulted in 55 publications 
in peer-reviewed journals.
    Currently, 14 priority data needs for 24 priority hazardous 
substances (including 15 PAHs) identified in the SSARP are being 
addressed through this program. The institutions receiving awards and 
their respective studies are listed in Table 2.

F. Other ATSDR Programs

    In its role as a public health agency addressing environmental 
health, ATSDR may collect human data to validate substance-specific 
exposure and toxicity findings. The need for additional information on 
levels of contaminants in humans has been identified, and remains as a 
priority data need for 49 of the first 50 priority substances (Table 
1). ATSDR will obtain this information through exposure and health 
effects studies, and through establishing and using substance-specific 
subregistries of people within the agency's National Exposure Registry 
who have potentially been exposed to these substances.
    The list of the 50 priority hazardous substances in the SSARP was 
forwarded to ATSDR's Exposure and Disease Registry Branch (EDRB), 
Division of Health Studies, for consideration as potential candidates 
for subregistries of exposed persons, based on criteria described in 
its 1994 document, ``National Exposure Registry: Policies and 
Procedures Manual (Revised),'' Agency for Toxic Substances and Disease 
Registry, Public Health Service, U.S. Department of Health and Human 
Services, Atlanta, Georgia, NTIS Publication No. PB95-154571. To date, 
of the first 50 priority substances in the SSARP, ATSDR has established 
subregistries for benzene, chromium, and trichloroethylene. Arsenic, 
cadmium, and lead are not considered to be in the pool of candidate 
substances for an exposure registry at this time, and, therefore, are 
not considered priority data needs. This decision will be reevaluated 
as more information on the chemicals and exposure sites become 
available. All other substances in the SSARP (Table 1) remain in the 
candidate pool and therefore continue to be classified as priority data 
needs. They will be considered for selection as primary contaminants 
during each selection process.

G. Conclusion

    The results of the research conducted via the SSARP are expected to 
provide information necessary to improve the database used to conduct 
comprehensive public health assessments of populations living near 
hazardous waste sites. The information will enable the agency to 
establish linkages between levels of contaminants in the environment 
and levels in human tissue and organs associated with adverse health 
effects, ultimately helping to determine methods for interdicting 
exposure and mitigating toxicity. This program will also provide

[[Page 4840]]

data that can be generalized to other substances or areas of science, 
including risk assessment of chemicals, thus creating a scientific 
information base for addressing a broader range of data needs. The 
agency plans to provide an update on the status of this research 
program approximately every 3 years.

    Dated: January 25, 2002.
Georgi Jones,
Director, Office of Policy and External Affairs, Agency for Toxic 
Substances and Disease Registry.

          Table 1.--ATSDR's Substance-Specific Priority Data Needs for 50 Priority Hazardous Substances
----------------------------------------------------------------------------------------------------------------
                                                                                 Status change
          Substances             PDN ID \1\    PDN description     Program \2\        \3\         Comments \4\
----------------------------------------------------------------------------------------------------------------
Aldrin/Dieldrin...............  1A            Dose-response      ..............  Filled.......  An MRL was
                                               data in animals                                   derived in the
                                               for intermediate-                                 2000 updated
                                               duration oral                                     toxicological
                                               exposure.                                         profile.
                                1B            Bioavailability
                                               from soil.
                                1C            Exposure levels    ..............  .............  This priority
                                               in humans living                                  data need,
                                               near hazardous                                    previously
                                               waste sites and                                   addressed in a
                                               other                                             study in the
                                               populations,                                      Great Lakes
                                               such as exposed                                   research
                                               workers.                                          program, is no
                                                                                                 longer
                                                                                                 investigated in
                                                                                                 that study.
                                1D            Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Arsenic.......................  2A            Comparative        EPA.                           ................
                                               toxicokinetic
                                               studies to
                                               determine if an
                                               appropriate
                                               animal species
                                               can be
                                               identified.
                                2B            Half-lives in      EPA...........
                                               surface water,
                                               groundwater.
                                2C            Bioavailability    EPA...........
                                               from soil.
                                2D            Exposure levels    G. Lakes......  Filled.......  Background level
                                               in humans living                                  data are
                                               near hazardous                                    available in
                                               waste sites and                                   ATSDR's 1993
                                               other                                             toxicological
                                               populations,                                      profile, and at
                                               such as exposed                                   least seven
                                               workers.                                          ATSDR studies
                                                                                                 that evaluated
                                                                                                 urine arsenic
                                                                                                 levels and
                                                                                                 potential
                                                                                                 adverse health
                                                                                                 effects are
                                                                                                 available.
                                                                                                 Also,
                                                                                                 additional
                                                                                                 studies are
                                                                                                 available in
                                                                                                 ATSDR's 2000
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile.
Benzene.......................  3A            Dose-response      EPA...........
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration oral
                                               exposure. The
                                               subchronic study
                                               should include
                                               an extended
                                               reproductive
                                               organ
                                               histopathology.
                                3B            Two-species        EPA...........  .............  Previously
                                               developmental                                     planned study
                                               toxicity study                                    in the MHPF
                                               via oral                                          research
                                               exposure.                                         program to
                                                                                                 address this
                                                                                                 priority data
                                                                                                 need was
                                                                                                 canceled.
                                3C            Neurotoxicology    EPA...........
                                               battery of tests
                                               via oral
                                               exposure.
                                3D            Epidemiologic      ..............  Filled.......  Based on an
                                               studies on the                                    evaluation of
                                               health effects                                    the data in
                                               of benzene                                        ATSDR's 1997
                                               (Special                                          updated
                                               emphasis end                                      toxicological
                                               points include                                    profile. ATSDR
                                               immunotoxicity).                                  will continue
                                                                                                 to evaluate new
                                                                                                 data as they
                                                                                                 become
                                                                                                 available to
                                                                                                 determine if
                                                                                                 additional
                                                                                                 studies are
                                                                                                 needed.
                                3E            Exposure levels    ..............  Filled.......  Reference range
                                               in humans living                                  concentrations
                                               near hazardous                                    are available
                                               waste sites and                                   (Ashley et al.
                                               other                                             1992, 1994;
                                               populations,                                      Needham et al.
                                               such as exposed                                   1995), and at
                                               workers.                                          least one ATSDR
                                                                                                 study that
                                                                                                 evaluated blood
                                                                                                 benzene levels
                                                                                                 and potential
                                                                                                 adverse health
                                                                                                 effects is
                                                                                                 available.
                                                                                                 ATSDR
                                                                                                 acknowledges
                                                                                                 that reference
                                                                                                 concentration
                                                                                                 data can
                                                                                                 support
                                                                                                 exposure and
                                                                                                 health
                                                                                                 assessments at
                                                                                                 waste sites,
                                                                                                 but the agency
                                                                                                 also continues
                                                                                                 to recognize
                                                                                                 the importance
                                                                                                 of collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.

[[Page 4841]]

 
Beryllium.....................  4A            Dose-response      EPA...........
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration
                                               inhalation
                                               exposures. The
                                               subchronic study
                                               should include
                                               extended
                                               reproductive
                                               organ
                                               histopathology.
                                4B            Two-species        EPA...........
                                               developmental
                                               toxicity study
                                               via inhalation
                                               exposure.
                                4C            Environmental      EPA...........
                                               fate in air;
                                               factors
                                               affecting
                                               bioavailability
                                               in air.
                                4D            Analytical         ..............  Filled.......  Based on an
                                               methods to                                        evaluation of
                                               determine                                         the data in
                                               environmental                                     ATSDR's 2000
                                               speciation.                                       updated
                                                                                                 toxicological
                                                                                                 profile.
                                4E            Immunotoxicology   EPA...........
                                               battery of tests
                                               following oral
                                               exposure.
                                4F            Exposure levels    ..............  Filled.......  Reference range
                                               in humans living                                  concentrations
                                               near hazardous                                    in urine are
                                               waste sites and                                   available
                                               other                                             (Paschal et al.
                                               populations,                                      1998). ATSDR
                                               such as exposed                                   acknowledges
                                               workers.                                          that reference
                                                                                                 concentration
                                                                                                 data can
                                                                                                 support
                                                                                                 exposure and
                                                                                                 health
                                                                                                 assessments at
                                                                                                 waste sites,
                                                                                                 but the agency
                                                                                                 also continues
                                                                                                 to recognize
                                                                                                 the importance
                                                                                                 of collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.
                                4G            Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Cadmium.......................  5A            Analytical         ..............  Filled.......  Based on an
                                               methods for                                       evaluation of
                                               biological                                        the data in
                                               tissues and                                       ATSDR's 1999
                                               fluids and                                        updated
                                               environmental                                     toxicological
                                               media.                                            profile.
                                5B            Exposure levels    G. Lakes......  Filled.......  Referent
                                               in humans living                                  population
                                               near hazardous                                    urine cadmium
                                               waste sites and                                   levels are
                                               other                                             available
                                               populations,                                      (NHANES III),
                                               such as exposed                                   and at least
                                               workers.                                          nine ATSDR
                                                                                                 studies that
                                                                                                 evaluated blood
                                                                                                 and urine
                                                                                                 cadmium levels
                                                                                                 and potential
                                                                                                 adverse health
                                                                                                 effects are
                                                                                                 available.
Carbon tetrachloride..........  6A            Dose-response
                                               data in animals
                                               for chronic oral
                                               exposure. The
                                               study should
                                               include extended
                                               reproductive
                                               organ and
                                               nervous tissue
                                               histopathology.
 
                                6B            Immunotoxicology   NTP...........  Filled.......  NTP dose-finding
                                               battery of tests                                  study and one
                                               via oral                                          new study in
                                               exposure.                                         ATSDR's 1994
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile
                                                                                                 addressed the
                                                                                                 priority data
                                                                                                 need.
 
                                6C            Half-life in soil  ..............  Filled.......  One new study in
                                                                                                 ATSDR's 1994
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile
                                                                                                 provided
                                                                                                 information on
                                                                                                 half-life in
                                                                                                 soil.
 
                                6D            Exposure levels    ..............  Filled.......  Reference range
                                               in humans living                                  concentrations
                                               near hazardous                                    in blood are
                                               waste sites and                                   available
                                               other                                             (Ashley et al.
                                               populations,                                      1992, 1994;
                                               such as exposed                                   Needham et al.
                                               workers.                                          1995). ATSDR
                                                                                                 acknowledges
                                                                                                 that reference
                                                                                                 concentration
                                                                                                 data can
                                                                                                 support
                                                                                                 exposure and
                                                                                                 health
                                                                                                 assessments at
                                                                                                 waste sites,
                                                                                                 but the agency
                                                                                                 also continues
                                                                                                 to recognize
                                                                                                 the importance
                                                                                                 of collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.
 

[[Page 4842]]

 
                                6E            Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Chlordane.....................  7A            Oral               MHPF..........  Filled.......  Availability of
                                               multigenerationa  NTP...........                  ongoing study
                                               l studies to                                      in the MHPF
                                               evaluate                                          research
                                               reproductive                                      program and
                                               toxicity.                                         anticipated
                                                                                                 initiation of
                                                                                                 an NTP study in
                                                                                                 2002.
 
                                7B            Bioavailability
                                               studies
                                               following
                                               ingestion of
                                               contaminated
                                               media.
 
                                7C            Exposure levels
                                               in humans living
                                               near hazardous
                                               waste sites and
                                               other
                                               populations
                                               potentially
                                               exposed to
                                               chlordane.
 
                                7D            Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Chloroethane..................  8A            Dose-response      EPA...........
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration oral
                                               exposures. The
                                               subchronic study
                                               should include
                                               an evaluation of
                                               immune and
                                               nervous system
                                               tissues, and
                                               extended
                                               reproductive
                                               organ
                                               histopathology.
 
                                8B            Dose-response      EPA...........
                                               data in animals
                                               for chronic
                                               inhalation
                                               exposures. The
                                               study should
                                               include an
                                               evaluation of
                                               nervous system
                                               tissues.
 
                                8C            Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Chloroform....................  9A            Dose-response      ..............  Filled.......  An MRL was
                                               data in animals                                   derived in
                                               for intermediate-                                 ATSDR's 1997
                                               duration oral                                     updated
                                               exposure.                                         toxicological
                                                                                                 profile.
 
                                9B            Epidemiologic      ..............  Filled.......  Based on an
                                               studies on the                                    evaluation of
                                               health effects                                    the data in
                                               of chloroform                                     ATSDR's 1997
                                               (Special                                          updated
                                               emphasis end                                      toxicological
                                               points include                                    profile. ATSDR
                                               cancer,                                           will continue
                                               neurotoxicity,                                    to evaluate new
                                               reproductive and                                  data as they
                                               developmental                                     become
                                               toxicity,                                         available to
                                               hepatotoxicity,                                   determine if
                                               and renal                                         additional
                                               toxicity).                                        studies are
                                                                                                 needed.
 
                                9C            Exposure levels    ..............  Filled.......  Reference range
                                               in humans living                                  concentrations
                                               near hazardous                                    in blood are
                                               waste sites and                                   available
                                               other                                             (Ashley et al.
                                               populations,                                      1992, 1994; and
                                               such as exposed                                   Needham et al.
                                               workers.                                          1995). ATSDR
                                                                                                 acknowledges
                                                                                                 that reference
                                                                                                 concentration
                                                                                                 data can
                                                                                                 support
                                                                                                 exposure and
                                                                                                 health
                                                                                                 assessments at
                                                                                                 waste sites,
                                                                                                 but the agency
                                                                                                 also continues
                                                                                                 to recognize
                                                                                                 the importance
                                                                                                 of collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.
 

[[Page 4843]]

 
                                9D            Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Chromium......................  10A           Dose-response      EPA...........
                                               data in animals
                                               for acute-
                                               duration
                                               exposure to
                                               chromium (VI)
                                               and (III) via
                                               oral exposure
                                               and for
                                               intermediate-
                                               duration
                                               exposure to
                                               chromium (VI)
                                               via oral
                                               exposure.
 
                                10B           Multigeneration    EPA...........
                                               reproductive
                                               toxicity study
                                               via oral
                                               exposure to
                                               chromium (III)
                                               and (VI).
 
                                10C           Immunotoxicology   EPA...........
                                               battery of tests
                                               following oral
                                               exposure to
                                               chromium (III)
                                               and (VI).
 
                                10D           Two-species        EPA...........
                                               developmental
                                               toxicity study
                                               via oral
                                               exposure to
                                               chromium (III)
                                               and (VI).
 
                                10E           Exposure levels    G. Lakes......  Filled.......  Reference range
                                               in humans living                                  concentrations
                                               near hazardous                                    in urine are
                                               waste sites and                                   available
                                               other                                             (Paschal et al.
                                               populations,                                      1998). Also, at
                                               such as exposed                                   least two ATSDR
                                               workers.                                          studies that
                                                                                                 evaluated urine
                                                                                                 chromium levels
                                                                                                 and potential
                                                                                                 adverse health
                                                                                                 effects are
                                                                                                 available. In
                                                                                                 addition, this
                                                                                                 PDN is being
                                                                                                 addressed in a
                                                                                                 study in the
                                                                                                 Great Lakes
                                                                                                 research
                                                                                                 program.
Cyanide.......................  11A           Dose-response      EPA...........
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration
                                               exposures via
                                               inhalation. The
                                               subchronic study
                                               should include
                                               extended
                                               reproductive
                                               organ
                                               histopathology
                                               and evaluation
                                               of
                                               neurobehavioral
                                               and
                                               neuropathologica
                                               l end points.
                                11B           Two-species        EPA...........
                                               developmental
                                               toxicity study
                                               via oral
                                               exposure.
                                11C           Evaluation of the  ..............  Filled.......  A study
                                               environmental                                     addressing the
                                               fate of cyanide                                   priority data
                                               in soil.                                          need was
                                                                                                 submitted by
                                                                                                 industry to EPA
                                                                                                 in response to
                                                                                                 EPA's
                                                                                                 solicitation
                                                                                                 for proposals
                                                                                                 for test rule
                                                                                                 making.
                                                                                                 Scientists from
                                                                                                 EPA and ATSDR
                                                                                                 reviewed the
                                                                                                 study and
                                                                                                 considered that
                                                                                                 this research
                                                                                                 need is no
                                                                                                 longer a
                                                                                                 priority.
                                11D           Exposure levels
                                               in humans living
                                               near hazardous
                                               waste sites and
                                               other
                                               populations,
                                               such as exposed
                                               workers.
                                11E           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
1,2-dibromo-3-chloropro pane..  12A           Dose-response
                                               data in animals
                                               for acute-
                                               duration
                                               exposure via the
                                               oral route
                                               (including
                                               reproductive
                                               organ
                                               histopathology).
                                12B           Dose-response
                                               data in animals
                                               for chronic-
                                               duration
                                               exposure via the
                                               oral route
                                               (including
                                               reproductive
                                               organ
                                               histopathology).
                                12C           Two-species
                                               developmental
                                               toxicity study
                                               via oral
                                               exposure.

[[Page 4844]]

 
                                12D           Immunotoxicology   ..............  .............  Previously
                                               testing battery                                   planned study
                                               via oral                                          in the MHPF
                                               exposure.                                         research
                                                                                                 program to
                                                                                                 address this
                                                                                                 priority data
                                                                                                 need was
                                                                                                 canceled.
                                12E           Neurotoxicology    ..............  .............  Previously
                                               testing battery                                   planned study
                                               via oral                                          in the MHPF
                                               exposure.                                         research
                                                                                                 program to
                                                                                                 address this
                                                                                                 priority data
                                                                                                 need was
                                                                                                 canceled.
                                12F           Exposure levels
                                               in humans living
                                               near hazardous
                                               waste sites and
                                               other exposed
                                               populations,
                                               such as exposed
                                               workers.
                                12G           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
DDT...........................  13A           Dose-response
                                               data in animals
                                               for chronic-
                                               duration oral
                                               exposure.
                                13B           Comparative
                                               toxicokinetic
                                               study (across
                                               routes/species).
                                13C           Bioavailability
                                               and
                                               bioaccumulation
                                               from soil.
                                13D           Epidemiologic      G. Lakes......  Filled.......  Multiple new
                                               studies on the                                    studies in
                                               health of DDT,                                    ATSDR's 2000
                                               DDD, and DDE                                      updated
                                               (Special                                          toxicological
                                               emphasis end                                      profile and
                                               points include                                    five ongoing
                                               immunotoxicity,                                   studies in the
                                               and reproductive                                  Great Lakes
                                               and                                               research
                                               developmental                                     program are
                                               toxicity.                                         available.
                                13E           Exposure levels    G. Lakes......
                                               in humans living
                                               near hazardous
                                               waste sites and
                                               other
                                               populations,
                                               such as exposed
                                               workers.
                                13F           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Di(2-ethyl-hexyl)phthalate....  14A           Epidemiologic
                                               studies on the
                                               health effects
                                               of DEHP (Special
                                               emphasis end
                                               points include
                                               cancer).
                                14B           Dose-response      ..............  .............  This research
                                               data in animals                                   need is
                                               for acute- and                                    reassigned as a
                                               intermediate-                                     priority data
                                               duration oral                                     need because of
                                               exposures. The                                    the data in
                                               subchronic study                                  ATSDR's 2000
                                               should include                                    updated
                                               an extended                                       toxicological
                                               histopathologic                                   profile.
                                               evaluation of                                     Specifically,
                                               the immunologic                                   the previously
                                               and neurologic                                    developed MRL
                                               systems.                                          for acute-
                                                                                                 duration (1993
                                                                                                 toxicological
                                                                                                 profile) was
                                                                                                 withdrawn, and
                                                                                                 a provisional
                                                                                                 MRL for
                                                                                                 intermediate-
                                                                                                 duration was
                                                                                                 derived
                                                                                                 replacing the
                                                                                                 previously
                                                                                                 established
                                                                                                 one.
                                14C           Multigeneration    ..............  .............  This research
                                               reproductive                                      need is
                                               toxicity study                                    reassigned as a
                                               via oral                                          priority data
                                               exposure.                                         need based on
                                                                                                 an evaluation
                                                                                                 of the data in
                                                                                                 ATSDR's 2000
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile. Also,
                                                                                                 the NTP Center
                                                                                                 for the
                                                                                                 Evaluation of
                                                                                                 Risks to Human
                                                                                                 Reproduction
                                                                                                 Expert Panel
                                                                                                 Report (October
                                                                                                 2000) has
                                                                                                 identified
                                                                                                 critical data
                                                                                                 needs for
                                                                                                 reproductive
                                                                                                 toxicity
                                14D           Comparative        ..............  .............  The NTP Center
                                               toxicokinetic                                     for the
                                               studies (Studies                                  Evaluation of
                                               designed to                                       Risks to Human
                                               examine how                                       Reproduction
                                               primates                                          Expert Panel
                                               metabolize and                                    Report (October
                                               distribute DEHP                                   2000) has also
                                               as compared with                                  identified
                                               rodents via oral                                  critical data
                                               exposure).                                        needs for
                                                                                                 toxicokinetic
                                                                                                 information.
                                14E           Exposure levels
                                               in humans living
                                               near hazardous
                                               waste sites and
                                               other
                                               populations,
                                               such as exposed
                                               workers.
                                14F           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.

[[Page 4845]]

 
Di-n-butyl phthalate..........  15A           Dose-response      NTP...........  Filled.......  NTP completed a
                                               data in animals                                   14-day study.
                                               for acute-
                                               duration
                                               exposure via the
                                               oral route.
                                15B           Dose-response
                                               data in animals
                                               for chronic-
                                               duration
                                               exposure via the
                                               oral route.
                                15C           Carcinogenicity
                                               studies via oral
                                               exposure.
                                15D           In vivo            MHPF..........  Filled.......  Availability of
                                               genotoxicity                                      ongoing studies
                                               studies.                                          in the MHPF
                                                                                                 research
                                                                                                 program.
                                15E           Immunotoxicology   ..............  .............  Previously
                                               studies via oral                                  planned study
                                               exposure.                                         in the MHPF
                                                                                                 research
                                                                                                 program to
                                                                                                 address this
                                                                                                 priority data
                                                                                                 need was
                                                                                                 canceled.
                                15F           Neurotoxicity      ..............  .............  Previously
                                               studies via oral                                  planned study
                                               exposure.                                         in the MHPF
                                                                                                 research
                                                                                                 program to
                                                                                                 address this
                                                                                                 priority data
                                                                                                 need was
                                                                                                 canceled.
                                15G           Exposure levels
                                               in humans living
                                               near hazardous
                                               waste sites and
                                               other
                                               populations,
                                               such as exposed
                                               workers.
                                15H           Environmental
                                               fate of di-n-
                                               butyl phthalate
                                               in environmental
                                               media.
                                15I           Bioavailability
                                               in contaminated
                                               environmental
                                               media near
                                               hazardous waste
                                               sites.
                                15J           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Disulfoton....................  16A           Immunotoxicology
                                               testing battery
                                               following oral
                                               exposure.
                                16B           Exposure levels
                                               of disulfoton in
                                               tissues/fluids
                                               for populations
                                               living near
                                               hazardous waste
                                               sites and other
                                               populations,
                                               such as exposed
                                               workers.
                                16C           Disulfoton should  ATSDR.........
                                               be considered as
                                               a potential
                                               candidate for a
                                               subregistry of
                                               exposed persons.
Endosulfan (,, and sulfate).                             oral exposure.
                                17B           Data on sensitive
                                               neurologic end
                                               point following
                                               oral exposure.
                                17C           Exposure levels
                                               in humans living
                                               near hazardous
                                               waste sites and
                                               other
                                               populations,
                                               such as exposed
                                               workers.
                                17D           Data on the
                                               bioavailability
                                               of endosulfan
                                               from soil.
                                17E           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Endrin/endrin aldehyde........  18A           Dose-response
                                               animal data for
                                               acute oral
                                               exposure to
                                               endrin.
                                18B           Multigeneration    NTP...........
                                               reproductive
                                               toxicity studies
                                               via oral
                                               exposure to
                                               endrin.
                                18C           Accurately
                                               describe the
                                               toxicokinetics
                                               of endrin and
                                               its degradation
                                               products and
                                               identify the
                                               animal species
                                               to be used as
                                               the most
                                               appropriate
                                               model for human
                                               exposure.
                                18D           Exposure levels
                                               for endrin and
                                               its degradation
                                               products in
                                               humans living
                                               near hazardous
                                               waste sites.

[[Page 4846]]

 
                                18E           Accurately
                                               describe the
                                               environmental
                                               fate of endrin,
                                               including
                                               environmental
                                               breakdown
                                               products and
                                               rates, media
                                               half-lives, and
                                               chemical and
                                               physical
                                               properties of
                                               the breakdown
                                               products that
                                               help predict
                                               mobility and
                                               volatility.
                                18F           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Heptachlor/heptachlor epoxide.  19A           Dose-response
                                               animal data for
                                               acute- and
                                               intermediate-
                                               duration oral
                                               exposures,
                                               including
                                               immunopathology.
                                19B           Multigeneration    NTP...........  Filled.......  Availability of
                                               reproductive                                      publication
                                               toxicity studies                                  ``The effects
                                               via the oral                                      of perinatal/
                                               route of                                          juvenile
                                               exposure.                                         heptachlor
                                                                                                 exposure on
                                                                                                 adult immune
                                                                                                 and
                                                                                                 reproductive
                                                                                                 system function
                                                                                                 in rats'' by
                                                                                                 Smialowicz et
                                                                                                 al. (2001),
                                                                                                 Toxicological
                                                                                                 Sciences 61:164-
                                                                                                 75.
                                19C           Two-species
                                               developmental
                                               toxicity studies
                                               via the oral
                                               route of
                                               exposure.
                                19D           Exposure levels
                                               in humans living
                                               near hazardous
                                               waste sites and
                                               other
                                               populations,
                                               such as exposed
                                               workers.
                                19E           Bioavailability
                                               from
                                               contaminated
                                               air, water, and
                                               soil and
                                               bioaccumulation
                                               potential.
                                19F           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Hexachloro-butadiene..........  20A           Dose-response
                                               data in animals
                                               for acute-
                                               duration
                                               exposure via the
                                               oral route.
                                20B           Exposure levels
                                               in humans living
                                               near hazardous
                                               waste sites and
                                               other
                                               populations,
                                               such as exposed
                                               workers.
                                20C           Environmental
                                               fate studies
                                               that determine
                                               the extent to
                                               which
                                               hexachlorobutadi
                                               ene volatilizes
                                               from soil, and
                                               studies that
                                               determine the
                                               reactions and
                                               rates which
                                               drive
                                               degradation in
                                               soil.
                                20D           Bioavailability
                                               studies in soil
                                               and plants.
                                20E           Potential          ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed person.
Hexachloro-cyclohexane (, , , and                 data for chronic-                                 derived in
 ).                                   duration oral                                     ATSDR's 1999
                                               exposure.                                         updated
                                                                                                 toxicological
                                                                                                 profile.
                                21B           Mechanistic
                                               studies on the
                                               neurotoxicity,
                                               hepatotoxicity,
                                               reproductive
                                               toxicity, and
                                               immunotoxicity
                                               of
                                               hexachlorocycloh
                                               exane.
                                21C           Exposure levels    ..............  Filled.......  Reference range
                                               in humans living                                  concentrations
                                               near hazardous                                    in blood are
                                               waste sites and                                   available.
                                               other                                             ATSDR
                                               populations,                                      acknowledges
                                               such as exposed                                   that reference
                                               workers.                                          concentration
                                                                                                 data can
                                                                                                 support
                                                                                                 exposure and
                                                                                                 health
                                                                                                 assessments at
                                                                                                 waste sites,
                                                                                                 but the agency
                                                                                                 also continues
                                                                                                 to recognize
                                                                                                 the importance
                                                                                                 of collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.

[[Page 4847]]

 
                                21D           Potential          ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
Lead..........................  22A           Mechanistic        MHPF..........  Filled.......  Multiple new
                                               studies on the                                    studies (13
                                               neurotoxic                                        publications
                                               effects of lead.                                  from the MHPF
                                                                                                 research
                                                                                                 program +
                                                                                                 numerous new
                                                                                                 published
                                                                                                 studies in
                                                                                                 ATSDR's 1999
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile) are
                                                                                                 available.
                                22B           Analytical         MHPF..........  Filled.......  A publication
                                               methods for                                       from the MHPF
                                               tissue levels.                                    research
                                                                                                 program and
                                                                                                 numerous
                                                                                                 studies in
                                                                                                 ATSDR's 1999
                                                                                                 toxicological
                                                                                                 profile are
                                                                                                 available.
                                22C           Exposure levels    MHPF..........  Filled.......  Referent
                                               in humans living  G. Lakes......                  population
                                               near hazardous                                    blood and urine
                                               waste sites and                                   lead levels are
                                               other                                             available
                                               populations,                                      (NHANES III;
                                               such as exposed                                   Paschal et al.
                                               workers.                                          1998), and at
                                                                                                 least 19 ATSDR
                                                                                                 studies that
                                                                                                 evaluated blood
                                                                                                 lead levels and
                                                                                                 potential
                                                                                                 adverse health
                                                                                                 effects are
                                                                                                 available.
Manganese.....................  23A           Dose-response      MHPF..........  Filled.......  Availability of
                                               data for acute-   EPA...........                  ongoing studies
                                               and intermediate-                                 in the MHPF
                                               duration oral                                     research
                                               exposures (the                                    program.
                                               subchronic study
                                               should include
                                               reproductive
                                               histopathology
                                               and an
                                               evaluation of
                                               immunologic
                                               parameters
                                               including
                                               manganese
                                               effects on
                                               plaque-forming
                                               cells (SRBC),
                                               surface markers
                                               (D4:D8 ratio),
                                               and delayed
                                               hypersensitivity
                                               reactions).
                                23B           Toxicokinetic      MHPF..........  Filled.......  Avaialbiltiy of
                                               studies on        EPA...........                  ongoing studies
                                               animals to                                        in the MHPF
                                               investigate                                       research
                                               uptake and                                        program.
                                               absorption,
                                               relative uptake
                                               of differing
                                               manganese
                                               compounds,
                                               metabolism of
                                               manganese, and
                                               interaction of
                                               manganese with
                                               other substances
                                               following oral
                                               exposure.
                                23C           Epidemiological    ..............  Filled.......  Based on
                                               studies on the                                    evaluation of
                                               health effects                                    the data in
                                               of manganese                                      ATSDR's 2000
                                               (Special                                          updated
                                               emphasis end                                      toxicological
                                               points include                                    profile. ATSDR
                                               neurologic,                                       will continue
                                               reproductive,                                     to evaluate new
                                               developmental,                                    data as they
                                               immunologic, and                                  become
                                               cancer).                                          available to
                                                                                                 determine if
                                                                                                 additional
                                                                                                 studies are
                                                                                                 needed.
                                23D           Exposure levels
                                               in humans living
                                               near hazardous
                                               waste sites and
                                               other
                                               populations,
                                               such as exposed
                                               workers.
                                23E           Relative           EPA.
                                               bioavailability
                                               of different
                                               manganese
                                               compounds and
                                               bioavialability
                                               of manganese
                                               from soil.
Mercury.......................  24A           Multigeneration    MHPF..........  Filled.......  Three
                                               reproductive                                      publications
                                               toxicity study                                    from the MHPF
                                               via oral                                          research
                                               exposure.                                         program are
                                                                                                 available.
                                24B           Dose-response      EPA...........  Filled.......  An MRL was
                                               data in animals                                   derived in
                                               for chronic-                                      ATSDR's 1999
                                               duration oral                                     updated
                                               exposure.                                         toxicological
                                                                                                 profile.
                                24C           Immunotoxicology   EPA.
                                               battery of tests
                                               via oral
                                               exposure.

[[Page 4848]]

 
                                24D           Exposure levels    G. Lakes......  Filled.......  Background
                                               in humans living                                  levels data are
                                               near hazardous                                    available in
                                               waste sites and                                   ATSDR's 1997
                                               other                                             updated
                                               populations,                                      toxicological
                                               such as exposed                                   profile, and
                                               workers.                                          multiple
                                                                                                 studies that
                                                                                                 evaluated
                                                                                                 blood, urine,
                                                                                                 and hair
                                                                                                 mercury levels
                                                                                                 and potential
                                                                                                 adverse health
                                                                                                 effects are
                                                                                                 available (Five
                                                                                                 ATSDR studies +
                                                                                                 at least eight
                                                                                                 ongoing studies
                                                                                                 of the Great
                                                                                                 Lakes research
                                                                                                 program).
                                24E           Potential          ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
Methoxychlor..................  25A           Evaluate           ..............  Filled.......  Based on an
                                               neurologic                                        evaluation of
                                               effects after                                     the data in
                                               long-term, low-                                   ATSDR's 2000
                                               level oral                                        updated
                                               exposure.                                         toxicological
                                                                                                 profile.
                                25B           Exposure levels
                                               of methoxychlor
                                               and primary
                                               metabolities in
                                               humans living
                                               near hazardous
                                               waste sites and
                                               in those
                                               individuals with
                                               the potential to
                                               ingest it.
                                25C           Evaluate the
                                               fate, transport,
                                               and levels of
                                               the degradation
                                               products of
                                               methoxychlor in
                                               soil.
                                25D           Potential          ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
Methylene chloride............  26A           Dose-response      EPA...........  Filled.......  ATSDR accepted
                                               data in animals   Vol Res.......                  HSIA's toxicity
                                               for acute- and                                    study for acute-
                                               intermediate-                                      and
                                               duration oral                                     intermediate-
                                               exposure. The                                     exposure
                                               subchronic study                                  duration in
                                               should include                                    February 1997.
                                               extended                                          ATSDR accepted
                                               reproductive                                      HSIAs
                                               organ                                             immunotoxicity
                                               histopathology,                                   study via
                                               neuropathology,                                   inhalation in
                                               and                                               November 2000.
                                               immunopathology.                                  Currently, HSIA
                                                                                                 is conducting
                                                                                                 PBPK modeling
                                                                                                 to obtain data
                                                                                                 for oral
                                                                                                 exposure using
                                                                                                 the data from
                                                                                                 its inhalation
                                                                                                 study.
                                                                                                 Neurotoxicity
                                                                                                 screening
                                                                                                 battery testing
                                                                                                 remains in the
                                                                                                 ATSDR/EPA test
                                                                                                 rule under
                                                                                                 development.
                                26B           Two-species        EPA...........  Filled.......  ATSDR accepted
                                               developmental     Vol Res.......                  HSIA's study in
                                               toxicity study                                    February 1997.
                                               via the oral
                                               route.
                                26C           Exposure levels    ..............  Filled.......  Reference range
                                               in humans living                                  concentrations
                                               near hazardous                                    in blood are
                                               waste sites and                                   available
                                               other                                             (Ashley et al.
                                               populations,                                      1992, 1994;
                                               such as exposed                                   Needham et al.
                                               workers.                                          1995). ATSDR
                                                                                                 acknowledges
                                                                                                 that reference
                                                                                                 concentration
                                                                                                 data can
                                                                                                 support
                                                                                                 exposure and
                                                                                                 health
                                                                                                 assessments at
                                                                                                 waste sites,
                                                                                                 but the agency
                                                                                                 also continues
                                                                                                 to recognize
                                                                                                 the importance
                                                                                                 of collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.
                                26D           Potential          ATSDR.                         ................
                                               candidate for
                                               subregistry of
                                               exposed persons.
Nickel........................  27A           Epidemiologic      ..............  Filled.......  At least two new
                                               studies on the                                    relevant
                                               health effects                                    studies in
                                               of nickel                                         ATSDR's 1997
                                               (Special                                          updated
                                               emphasis end                                      toxicological
                                               points include                                    profile are
                                               reproductive                                      available.
                                               toxicity.                                         ATSDR will
                                                                                                 continue to
                                                                                                 evaluate new
                                                                                                 data as they
                                                                                                 become
                                                                                                 available to
                                                                                                 determine if
                                                                                                 additional
                                                                                                 studies are
                                                                                                 needed.
                                27B           Two-species        EPA...........  Filed........  In ATSDR's 1997
                                               developmental                                     updated
                                               toxicity study                                    toxicological
                                               via the oral                                      profile, a new
                                               route.                                            study
                                                                                                 confirming the
                                                                                                 results of two
                                                                                                 previous
                                                                                                 studies is
                                                                                                 available

[[Page 4849]]

 
                                27C           Dose-response      EPA.                           ................
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration oral
                                               exposures.
                                27D           Neurotoxicology    EPA.                           ................
                                               battery of tests
                                               via oral
                                               exposure.
                                27E           Bioavailability    EPA.                           ................
                                               of nickel from
                                               soil.
                                27F           Exposure levels    G. Lakes......  Filled.......  Based on
                                               in humans living                                  availability of
                                               near hazardous                                    the study in
                                               waste sites and                                   the Great Lakes
                                               other                                             research
                                               populations,                                      program and an
                                               such as exposed                                   evaluation of
                                               workers.                                          ATSDR's 1997
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile.
                                27G           Potential          ATSDR.                         ................
                                               candidate for
                                               subregistry of
                                               exposed persons.
PAHs (Includes 15 substances).  28A           Dose-response      MHPF..........  Filled.......  MRLs for four
                                               data in animals                                   PAHs were
                                               for intermediate-                                 derived in
                                               duration oral                                     ATSDR's 1995
                                               exposures. The                                    updated
                                               subchronic study                                  toxological
                                               should include                                    profile. A
                                               extended                                          publication
                                               reproductive                                      from the MHPF
                                               organ                                             research
                                               histopathology                                    program
                                               and                                               addressing this
                                               immunopathology.                                  priority data
                                                                                                 need is
                                                                                                 available.
                                28B           Two-species        MHPF..........  Filled.......  Ongoing studies
                                               developmental                                     in the MHPF
                                               toxicity study                                    research
                                               via inhalation                                    program and one
                                               or oral exposure.                                 publication
                                                                                                 from the
                                                                                                 program are
                                                                                                 available.
                                28C           Mechanistic        MHPF..........  Filled.......  At least 12 new
                                               studies on PAHs,                                  studies in
                                               on how mixtures                                   ATSDR's 1995
                                               of PAHs can                                       updated
                                               influence the                                     toxicological
                                               ultimate                                          profile and two
                                               activation of                                     publications
                                               PAHs, and on how                                  from the MHPF
                                               PAHs affect                                       research
                                               rapidly                                           program are
                                               proliferating                                     available.
                                               tissues.
                                28D           Dose-response      MHPF..........  Filled.......  Ongoing studies
                                               data in animals                                   in the MHPF
                                               for acute- and                                    research
                                               intermediate-                                     program and one
                                               duration                                          publication
                                               inhalation                                        from the
                                               exposures. the                                    program are
                                               subchronic study                                  available.
                                               should include
                                               extended
                                               reproductive
                                               organ
                                               histopathology
                                               and
                                               immunopathology.
                                28E           Epidemiologic      ..............  Filled.......  At least three
                                               studies on the                                    new studies in
                                               health effects                                    ATSDR's 1995
                                               of PAHs (Special                                  updated
                                               emphasis end                                      toxicological
                                               points include                                    profile are
                                               cancer, dermal,                                   available.
                                               hemolymphatic,                                    ATSDR will
                                               and hepatic                                       continue to
                                               toxicity.                                         evaluate new
                                                                                                 data as they
                                                                                                 become
                                                                                                 available to
                                                                                                 determine if
                                                                                                 additional
                                                                                                 studies are
                                                                                                 needed.
                                28F           Exposure levels    G. Lakes......  Filled.......  Based on ongoing
                                               in humans living                                  study in the
                                               near hazardous                                    Great Lakes
                                               waste sites and                                   research
                                               other                                             program and an
                                               populations,                                      evaluation of
                                               such as exposed                                   the ATSDR 1995
                                               workers.                                          updated
                                                                                                 toxicological
                                                                                                 profile. Also,
                                                                                                 the agency
                                                                                                 continues to
                                                                                                 recognize the
                                                                                                 importance of
                                                                                                 collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.
                                28G           Potential          ATSDR.                         ................
                                               candidate for
                                               subregistry of
                                               exposed persons.
PCBs..........................  29A           Dose-response      G. Lakes......  .............  Although an MRL
                                               data in animals                                   for
                                               for acute- and                                    intermediate-
                                               intermediate-                                     exposure
                                               duration oral                                     duration was
                                               exposures.                                        derived in
                                                                                                 ATSDR's 2000
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile, an MRL
                                                                                                 for acute-
                                                                                                 exposure
                                                                                                 duration is
                                                                                                 still lacking.
                                29B           Biodegradation of                                 ................
                                               PCBs in water;
                                               bioavailability
                                               of PCBs in air,
                                               water, and soil.
                                29C           Dose-response
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration
                                               inhalation
                                               exposures. The
                                               subchronic study
                                               should include
                                               extended
                                               reproductive
                                               organ
                                               histopathology.

[[Page 4850]]

 
                                29D           Epidemiologic      G. Lakes......  Filled.......  Multiple new
                                               studies on the                                    published
                                               health effects                                    studies in
                                               of PCBs (Special                                  ATSDR's 2000
                                               emphasis end                                      updated
                                               points include                                    toxicological
                                               immunotoxicity,                                   profile and at
                                               gastrointestinal                                  least nine
                                               toxicity, liver                                   ongoing studies
                                               toxicity, kidney                                  in the Great
                                               toxicity,                                         Lakes research
                                               thyroid                                           program are
                                               toxicity, and                                     available.
                                               reproductive/
                                               developmental
                                               toxicity).
                                29E           Exposure levels    G. Lakes......  Filled.......  Background
                                               in humans living                                  levels data are
                                               near hazardous                                    available
                                               waste sites and                                   (ATSDR's 1997
                                               other                                             updated
                                               populations,                                      toxicological
                                               such as exposed                                   profile, and
                                               workers.                                          Needham et al.
                                                                                                 1996). Also,
                                                                                                 multiple
                                                                                                 studies that
                                                                                                 evaluated blood
                                                                                                 and breast milk
                                                                                                 PCB levels and
                                                                                                 potential
                                                                                                 adverse health
                                                                                                 effects are
                                                                                                 available (at
                                                                                                 least six ATSDR
                                                                                                 studies + at
                                                                                                 least eight
                                                                                                 ongoing studies
                                                                                                 in the Great
                                                                                                 Lakes research
                                                                                                 program).
                                29F           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
                                29G (5)       Chronic toxicity   Vol Res.......  Filled.......  ATSDR accepted
                                               and oncogenicity                                  the final
                                               via oral                                          report of the
                                               exposure.                                         GE in October
                                                                                                 1997.
                                29H (5)       Aerobic PCB        Vol Res.......  Filled.......  ATSDR accepted
                                               biodegradation                                    the final
                                               in sediment.                                      report of the
                                                                                                 GE study in
                                                                                                 July 1999.
                                29I (5)       PCB congener       Vol Res.......  Filled.......  ATSDR accepted
                                               analysis.         G. Lakes......                  the final
                                                                                                 report of the
                                                                                                 GE study in
                                                                                                 October 1997.
                                                                                                 Also, ongoing
                                                                                                 studies in the
                                                                                                 Great Lakes
                                                                                                 research
                                                                                                 program are
                                                                                                 available.
Selenium......................  30A           Dose-response      EPA...........
                                               data in animals
                                               for acute-
                                               duration oral
                                               exposure.
                                30B           Immunotoxicology   EPA...........
                                               battery of tests
                                               via oral
                                               exposure.
                                30C           Epidemiologic      ..............  Filled.......  Based on an
                                               studies on the                                    evaluation of
                                               health effects                                    ATSDR's 2001
                                               of selenium                                       updated
                                               (Special                                          toxicological
                                               emphasis end                                      profile. ATSDR
                                               points include                                    will continue
                                               cancer,                                           to evaluate new
                                               reproductive and                                  data as they
                                               developmental                                     become
                                               toxicity,                                         available to
                                               hepatotoxicity,                                   determine if
                                               and adverse skin                                  additional
                                               effects).                                         studies are
                                                                                                 needed.
                                30D           Exposure levels    G. Lakes......  Filled.......  Referent
                                               in humans living                                  population
                                               near hazardous                                    serum selenium
                                               waste sites and                                   levels are
                                               other                                             known (NHANES
                                               populations,                                      III). Two
                                               such as exposed                                   ongoing studies
                                               workers.                                          in the Great
                                                                                                 Lakes research
                                                                                                 program are
                                                                                                 available.
                                                                                                 ATSDR
                                                                                                 acknowledges
                                                                                                 that reference
                                                                                                 concentration
                                                                                                 data can
                                                                                                 support
                                                                                                 exposure and
                                                                                                 health
                                                                                                 assessments at
                                                                                                 waste sites,
                                                                                                 but the agency
                                                                                                 also continues
                                                                                                 to recognize
                                                                                                 the importance
                                                                                                 of collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.
                                30E           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Tetrach loroethy lene.........  31A           Dose-response      ..............  Filled.......  An MRL was
                                               data in animals                                   derived in the
                                               for acute-                                        1997 updated
                                               duration oral                                     toxicological
                                               exposure,                                         profile.
                                               including
                                               neuropathology
                                               and demeanor,
                                               and
                                               immunopathology.

[[Page 4851]]

 
                                31B           Multigeneration    Vol Res.......  .............  HSIA's
                                               reproductive                                      inhalation
                                               toxicity study                                    study was
                                               via oral                                          accepted by
                                               exposure.                                         ATSDR and
                                                                                                 included in
                                                                                                 ATSDR's 1997
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile.
                                                                                                 However, ATSDR
                                                                                                 has identified
                                                                                                 ingestion of
                                                                                                 contaminated
                                                                                                 environmental
                                                                                                 media to be the
                                                                                                 primary
                                                                                                 exposure route
                                                                                                 for this
                                                                                                 chemical at
                                                                                                 waste sites.
                                                                                                 HSIA plans to
                                                                                                 obtain the oral
                                                                                                 data from the
                                                                                                 inhalation
                                                                                                 study by
                                                                                                 conducting PBPK
                                                                                                 modeling.
                                31C           Dose-response      EPA...........  .............  HSIA intends to
                                               data in animals   Vol Res.......                  obtain oral
                                               for intermediate-                                 data for
                                               duration oral                                     neurotoxicity
                                               exposure,                                         by PBPK
                                               including                                         modeling, and
                                               neuropathology,                                   to conduct an
                                               and                                               immunotoxicity
                                               immunopathology.                                  study.
                                31D           One-species        EPA...........
                                               developmental     Vol Res.......
                                               toxicity study
                                               via oral
                                               exposure.
                                31E           Developmental      EPA...........
                                               neurotoxicity     Vol Res.......
                                               study via oral
                                               exposure.
                                31F           Exposure levels    ..............  Filled.......  Reference range
                                               in humans living                                  concentrations
                                               near hazardous                                    in blood are
                                               waste sites and                                   available
                                               other                                             (Ashley et al.
                                               populations,                                      1992, 1994;
                                               such as exposed                                   Needham et al.
                                               workers.                                          1995). ATSDR
                                                                                                 acknowledges
                                                                                                 that reference
                                                                                                 concentration
                                                                                                 data can
                                                                                                 support
                                                                                                 exposure and
                                                                                                 health
                                                                                                 assessments at
                                                                                                 waste sites,
                                                                                                 but the agency
                                                                                                 also continues
                                                                                                 to recognize
                                                                                                 the importance
                                                                                                 of collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.
                                31G           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Toluene.......................  32A           Dose-response      EPA...........  Filled.......  Availability of
                                               data in animals                                   MRLs for acute-
                                               for acute- and                                    and
                                               intermediate-                                     intermediate-
                                               duration oral                                     exposure
                                               exposures. The                                    durations in
                                               subchronic study                                  ATSDR's 2000
                                               should include                                    updated
                                               an extended                                       toxicological
                                               histopathologic                                   profile.
                                               evaluation of                                     Immunotoxicity
                                               the immune                                        study remains
                                               system.                                           in the ATSDR/
                                                                                                 EPA test rule
                                                                                                 under
                                                                                                 development.
                                32B           Comparative        ..............  Filled.......  Based on
                                               toxicokinetic                                     evaluation of
                                               studies                                           the data in
                                               (Characterizatio                                  ATSDR's 2000
                                               n of absorption,                                  updated
                                               distribution,                                     toxicological
                                               and excretion                                     profile.
                                               via oral
                                               exposure).
                                32C           Neurotoxicology    EPA...........
                                               battery of tests  MHPF..........
                                               via oral
                                               exposure.
                                32D           Mechanism of       ..............  Filled.......  At least 15
                                               toluene-induced                                   studies in
                                               neurotoxicity.                                    ATSDR's 1994
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile and
                                                                                                 additional new
                                                                                                 data in ATSDR's
                                                                                                 2000 updated
                                                                                                 toxicological
                                                                                                 profile are
                                                                                                 available.
                                32E           Exposure levels    ..............  Filled.......  Reference range
                                               in humans living                                  concentrations
                                               near hazardous                                    in blood are
                                               waste sites and                                   available
                                               other                                             (Ashley et al.
                                               populations,                                      1992, 1994;
                                               such as exposed                                   Needham et al.
                                               worker.                                           1995), and
                                                                                                 additional data
                                                                                                 in ATSDR's 2000
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile are
                                                                                                 available.
                                                                                                 ATSDR
                                                                                                 acknowledges
                                                                                                 that reference
                                                                                                 concentration
                                                                                                 data can
                                                                                                 support
                                                                                                 exposure and
                                                                                                 health
                                                                                                 assessments at
                                                                                                 waste sites,
                                                                                                 but the agency
                                                                                                 also continues
                                                                                                 to recognize
                                                                                                 the importance
                                                                                                 of collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.
                                32F           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.

[[Page 4852]]

 
Toxaphene.....................  33A           Identify the long-
                                               term health
                                               consequences of
                                               exposure to
                                               environmental
                                               toxaphene via
                                               oral exposure..
                                33B           Conduct
                                               additional
                                               immunotoxicity
                                               studies for
                                               chronic-duration
                                               via oral route
                                               of exposure.
                                33C           Conduct
                                               additional
                                               neurotoxicity
                                               studies for
                                               chronic-duration
                                               via oral route
                                               of exposure.
                                33D           Exposure levels
                                               in humans living
                                               in areas near
                                               hazardous waste
                                               sites with
                                               toxaphene and in
                                               those
                                               individuals with
                                               the potential to
                                               ingest it.
                                33E           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons..
Trichloroethylene.............  34A           Dose-response      ..............  Filled.......  An MRL was
                                               data in animals                                   derived in
                                               for acute-                                        ATSDR's 1997
                                               duration oral                                     updated
                                               exposure.                                         toxicological
                                                                                                 profile.
                                34B           Dose-response      EPA...........
                                               data in animals   Vol Res.......
                                               for intermediate-
                                               duration oral
                                               exposure.
                                34C           Neurotoxicology    EPA...........
                                               battery of tests  MHPF..........
                                               via the oral      Vol Res.......
                                               route.
                                34D           Immunotoxicology    EPA..........
                                               battery of tests  Vol Res.......
                                               via the oral
                                               route.
                                34E           One-species        Vol Res.......  .............  ATSDR accepted
                                               developmental                                     HSIA's final
                                               toxicity study                                    report for an
                                               via oral                                          inhalation
                                               exposure.                                         developmental
                                                                                                 toxicity study
                                                                                                 in September
                                                                                                 2001. HSIA is
                                                                                                 currently using
                                                                                                 PBPK modeling
                                                                                                 to obtain data
                                                                                                 for oral
                                                                                                 exposure using
                                                                                                 the data from
                                                                                                 its inhalation
                                                                                                 study.
                                34F           Developmental      EPA...........
                                               neurotoxicity     Vol Res.......
                                               study via oral
                                               exposure.
                                34G           Epidemiologic      ..............  Filled.......  Based on
                                               studies on the                                    evaluation of
                                               health effects                                    the data in
                                               of                                                ATSDR's 1997
                                               trichloroethylen                                  updated
                                               e (Special                                        toxicological
                                               emphasis end                                      profile. ATSDR
                                               points include                                    will continue
                                               cancer,                                           to evaluate new
                                               hepatotoxicity,                                   data as they
                                               renal toxicity,                                   become
                                               developmental                                     available to
                                               toxicity, and                                     determine if
                                               neurotoxicity).                                   additional
                                                                                                 studies are
                                                                                                 needed.
                                34H           Exposure levels    ..............  Filled.......  Reference range
                                               in humans living                                  concentrations
                                               near hazardous                                    in blood are
                                               waste sites and                                   available
                                               other                                             (Ashley et al.
                                               populations,                                      1992, 1994;
                                               such as exposed                                   Needham et al.
                                               workers.                                          1995). ATSDR
                                                                                                 acknowledges
                                                                                                 that reference
                                                                                                 concentration
                                                                                                 data can
                                                                                                 support
                                                                                                 exposure and
                                                                                                 health
                                                                                                 assessments at
                                                                                                 waste sites,
                                                                                                 but the agency
                                                                                                 also continues
                                                                                                 to recognize
                                                                                                 the importance
                                                                                                 of collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.
Vinyl chloride................  35A           Dose-response      ..............  Filled.......  An MRL was
                                               data in animals                                   derived in
                                               for acute-                                        ATSDR's 1997
                                               duration                                          updated
                                               inhalation                                        toxicological
                                               exposure.                                         profile.
                                35B           Multigeneration    Vol Res.......  Filled.......  ATSDR accepted
                                               reproductive                                      the final
                                               toxicity study                                    report of ACC's
                                               via inhalation.                                   study in
                                                                                                 November 2000.
                                35C           Dose-response
                                               data in animals
                                               for chronic-
                                               duration
                                               inhalation
                                               exposure.
                                35D           Mitigation of
                                               vinyl chloride-
                                               induced toxicity.

[[Page 4853]]

 
                                35E           Two-species        Vol Res.......  Filled.......  ATSDR accepted
                                               developmental                                     the final
                                               toxicity study                                    report of ACC's
                                               via inhalation..                                  study in
                                                                                                 November 2000.
                                35F           Exposure levels
                                               in humans living
                                               near hazardous
                                               waste sites and
                                               other
                                               populations,
                                               such as exposed
                                               workers.
                                35G           Potential          ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Zinc..........................  36A           Dose-response      MHPF..........  Filled.......  Ongoing studies
                                               data in animals                                   in the MHPF
                                               for acute- and                                    research
                                               intermediate-                                     program are
                                               duration oral                                     available.
                                               exposures. The
                                               subchronic study
                                               should include
                                               an extended
                                               histopathologic
                                               evaluation of
                                               the immunologic
                                               and neurologic
                                               systems.
                                36B           Multigeneration    MHPF..........
                                               reproductive
                                               toxicity study
                                               via oral
                                               exposure.
                                36C           Carcinogenicity
                                               testing (2-year
                                               bioassay) via
                                               oral exposure.
                                36D           Exposure levels    ..............  .............  This priority
                                               in humans living                                  data need,
                                               near hazardous                                    previously
                                               waste sites and                                   anticipated to
                                               other                                             be addressed
                                               populations,                                      under the
                                               such as exposed                                   voluntary
                                               workers.                                          research
                                                                                                 program, is not
                                                                                                 being
                                                                                                 investigated
                                                                                                 under any of
                                                                                                 the ATSDR
                                                                                                 research
                                                                                                 programs.
                                36E           Potential          ATSDR ........
                                               candidate for
                                               subregistry of
                                               exposed persons.
----------------------------------------------------------------------------------------------------------------
\1\ Priority data need identification number.
\2\ Programs addressing data needs. ATSDR=ATSDR's Division of Health Studies; EPA=Environmental Protection
  Agency; G. Lakes=Great Lakes Human Health Effects Research Program; MHPF=Minority Health Professions
  Foundation schools; NTP=National Toxicology Program; Vol Res=Voluntary research.
\3\ PDN can be filled or remain unchanged based on reevaluation of the database using criteria developed by
  ATSDR.
\4\ ACC=American Chemistry Council; Ashley et al. 1992=Ashley DL, Bonin MA, Cardinali FL, et al. Anal Chem
  (1992) 64:1021-29; Ashley et al. 1994=Ashley DL, Bonin MA, Cardinali FL et al., Clin Chem (1994) 40/7:1401-4;
  ATSDR studies=Studies conducted by ATSDR's Division of Health Studies; GE=General Electric Company ;
  HSIA=Halogenated Solvents Industry Alliance, Inc.; MHPF=Minority Health Professions Foundation schools;
  MRL=Minimal Risk Level; Needham et al. 1995=Needham LL, Hill RH Jr, Ashley DL, Pirkle JL, and Sampson EJ.
  Environ Health Perspect 103 (Suppl 3):89-94; Needham et al. 1996=Needham LL, Patterson DG Jr, Burse VW,
  Paschal DC, Turner WE, and Hill VW Jr. Toxicol Ind Health 12:507-513; NHANES III=The Third National Health and
  Nutrition Examination Survey, conducted by the National Center for Health Statistics, Centers for Disease
  Control and Prevention, Atlanta, GA; NTP=National Toxicology Program; Paschal et al. 1998=Paschal DC, Ting BC,
  Morrow JC, et al. Environ Res, Section A 76: 53-59; PBPK modeling=physiologically based pharmacokinetic
  modeling; Toxicological profile=ATSDR's toxicological profiles for the agency's priority hazardous substances.
 
\5\ Not a priority data need.


                Table 2.--Groups Addressing ATSDR's Substance-Specific Priority Data Needs (PDNs)
----------------------------------------------------------------------------------------------------------------
                                          Firm, institution,
            ATSDR program               agency, or consortium          Substance                  PDN ID
----------------------------------------------------------------------------------------------------------------
Voluntarism..........................  American Chemistry       Vinyl Chloride.........  35B, 35E
                                        Council.
                                       General Electric         PCBs...................  29G,* 29H,* 29I*
                                        Company.
                                       Halogenated Solvents     Methylene chloride.....  26A, 26B
                                        Industry Alliance, Inc. Tetrachloroethylene....  31B, 31C,
                                                                  .....................  31D, 31E
                                                                Trichloroethylene......  34B, 34C,
                                                                                         34D, 34E,
                                                                                         34F
Minority Health Professions            Florida A & M            Lead...................  22A
 Foundation Schools.                    University.
                                       The King/Drew Medical    Lead...................  22B, 22C
                                        Center of the Charles
                                        R. Drew University of
                                        Medicine and Science.
                                       Meharry Medical College  PAHS...................  28A, 28B, 28C, 28D
                                       Morehouse School of      Lead...................  22C
                                        Medicine.
                                       Texas Southern           Di-n-butyl phthalate...  15D
                                        University.             Lead...................  22A
                                                                Toluene................  32C
                                                                Trichloroethylene......  34C

[[Page 4854]]

 
                                       Tuskegee University....  Chlordane..............  7A
                                                                Mercury................  24A
                                                                Zinc...................  36A, 36B
                                       Xavier University......  Manganese..............  23A, 23B
                                                                Zinc...................  36A
Great Lakes Human Health Effects       Michigan State           DDT/DDE................  13D, 13E
 Research Program.                      University.             Lead...................  22C
                                                                Mercury................  24D
                                                                PCBs...................  29D, 29E, 29I
                                                                Selenium...............  30D
                                       New York State Health    DDT/DDE................  13E
                                        Department.             Lead...................  22C
                                                                Mercury................  24D
                                                                PCBs...................  29D, 29E, 29I
                                       State University of New  DDT/DDE................  13D, 13E
                                        York at Buffalo.        Lead...................  22C
                                                                Mercury................  24D
                                                                PCBs...................  29D, 29E, 291
                                       State University of New  DDT/DDE................  13D, 13E
                                        York at Oswego.         Lead...................  22C
                                                                Mercury................  24D
                                                                PCBs...................  29D, 29E, 29I
                                       University of Illinois   DDT/DDE................  13D, 13E
                                        at Chicago.             Lead...................  22C
                                                                Mercury................  24D
                                                                PCBs...................  29D, 29E, 291
                                       University of Illinois   DDT/DDE................  13D, 13E
                                        at Urbana-Champaign.    Lead...................  22C
                                                                Mercury................  24D
                                                                PCBs...................  29D, 29E, 29I
                                       University of            DDT/DDE................  13D, 13E
                                        Wisconsin--Milwaukee.   Lead...................  22C
                                                                Mercury................  24D
                                                                PCBs...................  29A, 29D, 29E, 29I
                                                                Selenium...............  30D
                                       Wisconsin Department of  Arsenic................  2D
                                        Health and Social       Cadmium................  5B
                                        Services--5 State       Chromium...............  10E
                                        Consortium.             DDT/DDE................  13D, 13E
                                                                Lead...................  22C
                                                                Mercury................  24D
                                                                Nickel.................  27F
                                                                PAHs...................  28F
                                                                PCBs...................  29D, 29E, 29I
Environmental Protection Agency TSCA/  ATSDR Test Rule........  Benzene................  3A, 3B, 3C
 FIFRA.                                                         Chloroethane...........  8A, 8B
                                                                Cyanide (hydrogen        11A, 11B
                                                                 cyanide and sodium
                                                                 cyanide).
                                                                Methylene chloride.....  26A, 26B
                                                                Tetrachloroethylene....  31C, 31D, 31E
                                                                Toluene................  32A, 32C
                                                                Trichloroethylene......  34B, 34C, 34D, 34F
                                       Metals Testing Task      Arsenic................  2A, 2B, 2C
                                        Force (TASARC).         Beryllium..............  4A, 4B, 4C, 4E
                                                                Chromium...............  10A, 10B, 10C, 10D
                                                                Manganese..............  23A, 23B, 23E
                                                                Mercury................  24B, 24C
                                                                Nickel.................  27B, 27C, 27D, 27E
                                                                Selenium...............  30A, 30B
National Toxicology Program..........  National Institute of    Carbon Tetrachloride...  6B
                                        Environmental Health    Chlordane..............  7A
                                        Sciences.               Di-n-butyl phthalate...  15A
                                                                Endrin.................  18B
                                                                Heptachlor.............  19B
----------------------------------------------------------------------------------------------------------------
* Not priority data needs.


[FR Doc. 02-2421 Filed 1-30-02; 8:45 am]
BILLING CODE 4163-70-P