[Federal Register Volume 70, Number 228 (Tuesday, November 29, 2005)]
[Notices]
[Pages 71506-71531]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-23361]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Agency for Toxic Substances and Disease Registry

[ATSDR-215]


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

AGENCY: Agency for Toxic Substances and Disease Registry (ATSDR), U.S. 
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 2002 (67 FR 4836). 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 (68 FR 63098, November 7, 2003), 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.
    More recently, priority data needs for 10 additional hazardous 
substances frequently found at waste sites were determined and 
announced in the Federal Register (68 FR 22704). The ten 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-dichloroethene, 
ethylbenzene, pentachlorophenol, 1,1,2,2-tetrachloroethane, and total 
xylenes.
    Currently, the priority data needs for acrolein and barium are 
being identified and will be reported in a future Federal Register 
notice.
    To date, 270 priority data needs have been identified for the 60 
hazardous substances, and 86 priority data needs have been filled 
(Table 1). ATSDR fills these research needs through U.S. Environmental 
Protection Agency (EPA) regulatory mechanisms (test rules), private-
sector voluntarism, and the direct use of CERCLA funds. Additional 
priority 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. 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, National Institute of Environmental Health Sciences 
(NIEHS)/NTP, and the EPA, will review all proposed voluntary research 
studies.

DATES: ATSDR provides updates on the status of its Substance-Specific 
Applied Research Program approximately every three years or sooner, as 
needed. 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 Yee-Wan Stevens, M.S., Applied Toxicology 
Branch, Division of Toxicology and Environmental Medicine, ATSDR, 1600 
Clifton Road, NE., Mailstop F-32, 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 ten or more individuals and funded by cooperative 
agreement will be subject to review by the Office of

[[Page 71507]]

Management and Budget (OMB) under the Paperwork Reduction Act.

FOR FURTHER INFORMATION CONTACT: Yee-Wan Stevens, M.S., Applied 
Toxicology Branch, Division of Toxicology and Environmental Medicine, 
ATSDR, 1600 Clifton Road, NE., Mailstop F-32, Atlanta, Georgia 30333, 
telephone: (770) 488-3325, fax: (770) 488-4178.

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, in conjunction with NTP, 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 
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, NIEHS/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 12 times since the initiation of the SSARP. It has 
guided referral of priority 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 priority 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.

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.
    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 (Exception: priority data 
needs referred to EPA [i.e., included in the EPA/ATSDR test rule] and/
or ATSDR Voluntary Research Program remain as priority data needs until 
the studies have been completed, peer reviewed and accepted by ATSDR), 
or
     If an updated ATSDR toxicological profile contains 
relevant new studies, or if other relevant, peer-reviewed, and publicly 
available new studies (not included in the toxicological profile) have 
been identified since the finalization of the priority data needs 
document; and based on such studies, it is generally agreed that a 
priority data need has been filled.
    Furthermore, 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.
    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 and/or ATSDR Voluntary Research Program, or 
it is associated with a pilot substance in EPA's Voluntary Children's 
Chemical Evaluation Program.

Specific Criteria

    Examples of specific criteria for two categories of priority data 
needs are 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

[[Page 71508]]

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 (adults and/or children)--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., the Centers for Disease Control and Prevention's 
Third National Report on Human Exposure to Environmental Chemicals, 
with data from a random sample of participants from the 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 for some of the 
chemicals listed in the National Report, the measurements are reported 
as below the limit of detection (LOD) for those chemicals. However, the 
LODs for all the chemicals monitored are available in the Report, and 
therefore, these data can be considered as estimates of background 
exposure levels.
    In updating the SSARP, the status of the priority data needs may 
change 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 were not 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, in addressing issues 
relating to children's health, ATSDR considers it a priority to obtain 
data on exposure levels in children; therefore, when such information 
is available, it is used to fill this additional priority data need 
(e.g., cadmium, chlordane, chlorinated dibenzo-p-dioxins, DDT, lead, 
and pentachlorophenol, see Table 1).
    In contrast, the Agency may consider a previously identified 
priority data need to no longer be a priority to fill at this time and 
thus be deleted from the list of priority data needs. However, it 
remains a data need for the Agency. For example, as a result of 
reevaluation of the database for di-n-butyl phthalate, two of its 
previously identified priority data needs, i.e., immunotoxicity and 
neurotoxicity studies via oral exposure are no longer considered to be 
priority data needs. This is due to the fact that the immune system 
does not appear to be a target for di-n-butyl phthalate toxicity and 
that additional neurotoxicity studies do not seem necessary because of 
the lack of effects seen in long-term neurotoxicity studies. In 
addition, under the Agency's Voluntary Research Program, the 
Halogenated Solvents Industry Alliance, Inc. (HSIA) proposed to fill a 
trichloroethylene priority data need (dose-response data for 
intermediate-duration, oral exposure) by conducting PBPK modeling to 
obtain the data for oral exposure using existing inhalation data. 
However, ATSDR is concerned that, based on the existing data for this 
exposure duration, it is not clear if the most sensitive end point for 
oral exposure is the same as that for inhalation exposure. Therefore, 
the Agency believes it is prudent not to consider it a priority to 
conduct a PBPK study to obtain the oral data at this time pending 
evaluation of additional information. This is reflected in Table 1 from 
which this priority data need has been deleted.

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.

A. TSCA/FIFRA

    In developing and implementing the SSARP, ATSDR, NIEHS/NTP, and EPA 
have identified a subset of priority data needs for substances of 
mutual interest to the federal programs. These priority data needs are 
being addressed through a program of toxicological 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 considers 
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 priority 
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 13 
ATSDR priority data needs (Table 2). The test rule is presently 
undergoing ATSDR and EPA final review and is anticipated to be 
available for public comment in Spring 2006.
    At least seven metals included in the ATSDR's SSARP (arsenic, 
beryllium, chromium, manganese, mercury, nickel, and selenium, 
associated with 21 priority data needs) (Table 2) have been forwarded 
to EPA through TASARC for toxicity testing. The EPA is currently 
developing a risk assessment framework for metals. Once the framework 
has been adopted, the EPA will solicit testing proposals for these 
metals and pursue appropriate testing mechanisms at a later date.

B. Private-Sector Voluntarism

    As part of the Substance-Specific Applied Research Program (SSARP), 
ATSDR announced a set of proposed procedures for conducting voluntary 
research in the Federal Register (57 FR 4758) on February 7, 1992. 
Revisions based on public comments were published on November 16, 1992 
(57 FR 54160). Private-sector organizations are encouraged to volunteer 
to conduct research to fill specific priority data needs at no expense 
to ATSDR. All study protocols and final reports are subjected to 
ATSDR's external peer review, and ATSDR accepts the study results based 
on the peer reviewers' recommendation and the industry groups' 
satisfactory response to the reviewers' comments.
    To date, ATSDR has established memoranda of understanding with four 
industry groups. Through the voluntary research efforts of these 
organizations, at least 15 research needs (12 priority data needs and 3 
data needs) for methylene chloride, tetrachloroethylene 
(perchloroethylene), trichloroethylene, polychlorinated biphenyl 
compounds [PCBs], and vinyl chloride have been or are being filled 
(Table 2).
    Industry groups which conducted studies under the Voluntary 
Research Program include:

The American Chemistry Council (ACC) [Formerly the Chemical 
Manufacturers Association (CMA)]

    ATSDR accepted the ACC studies ``Vinyl chloride: Combined 
inhalation two-generation reproduction and developmental toxicity study 
in CD rats.''

General Electric Company (GE)

    GE conducted studies on polychlorinated biphenyls including ``An 
assessment of the chronic toxicity and oncogenicity of Aroclors 1016,

[[Page 71509]]

1242, 1254, and 1260 administered in diet to rats,'' ``PCB congener 
analyses,'' and ``Metabolite detection as a tool for determining 
naturally occurring aerobic PCB biodegradation.'' Although these 
studies do not specifically address ATSDR's priority data needs for 
PCBs, they do address other Agency research needs for these substances.

Halogenated Solvents Industry Alliance, Inc. (HSIA)

    To date, ATSDR has entered into five MOUs with HSIA to conduct 
studies to fill priority data needs for methylene chloride, 
tetrachloroethylene and trichloroethylene. In addition, in 2002, HSIA 
signed a letter of agreement with ATSDR stating that HSIA volunteers to 
conduct studies to fill ATSDR's remaining priority data needs for 
tetrachloroethylene (perchloroethylene) and trichloroethylene. These 
studies are being done in conjunction with the EPA/ATSDR test rule and 
EPA's Voluntary Children's Chemical Evaluation Program. In some cases, 
HSIA first conducted a study via inhalation which was followed by route 
extrapolation via PBPK modeling to obtain data for oral exposure. This 
is because, for specific chemicals, EPA requires inhalation data while 
ATSDR has determined that ingestion of contaminated environmental media 
is the primary exposure route at hazardous waste sites.
    HSIA studies accepted by ATSDR include:
    ``Addressing priority data needs for methylene chloride with 
physiologically based pharmacokinetic modeling'' which evaluates acute- 
and subchronic-duration toxicity and developmental toxicity via oral 
exposure.
    ``Methylene chloride: 28 day inhalation toxicity study in the rat 
to assess potential immunotoxicity.''
    ``Immunotoxic potential of orally administered dichloromethane from 
immunotoxicity studies conducted by the inhalation route.'' (PBPK 
modeling)
    ``Trichloroethylene: Inhalation developmental toxicity study in CD 
rats.'' HSIA will conduct PBPK modeling to obtain data for oral 
exposure based on the inhalation data.
    ``Trichloroethylene (TCE): Immunotoxicity potential in CD rats 
following a 4-week vapor inhalation exposure.'' The final report of the 
study is undergoing ATSDR's external peer review. Pending ATSDR's 
acceptance of the inhalation study, HSIA will conduct PBPK modeling to 
obtain data for oral exposure based on the inhalation data.
    ``Perchloroethylene: Study of effects on embryo-fetal development 
in CD rats by inhalation administration.'' HSIA will conduct PBPK 
modeling to obtain data for oral exposure based on the inhalation data.

Electric Power Research Institute, Inc. (EPRI)

    In addition to the substance-specific MOUs described above, ATSDR 
also signed an MOU with EPRI to conduct a study ``Validation of test 
methods for assessing neurodevelopment in children.'' In this 
particular case, ATSDR and three other federal agencies (the Food and 
Drug Administration, EPA, and NIEHS) were also funding partners.

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 at historically black colleges and 
universities. The MHPF mission is to research health problems that 
disproportionately affect poor and minority citizens. The purpose of 
the cooperative agreement was to address substance-specific data needs 
for priority hazardous substances identified by ATSDR. In addition, the 
agreement strengthened the environmental health research opportunities 
for scientists and students at MHPF member institutions and enhanced 
existing disciplinary capacities to conduct research in toxicology and 
environmental health. The MHPF published 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.
    In the first five 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. 
Research initiated in the second 5-year project period included studies 
to address 10 additional priority data needs for chlordane, di-n-butyl 
phthalate, lead, manganese, the polycylic aromatic hydrocarbons (PAHs), 
zinc, and eight other research needs. To date, 14 priority data needs 
have been filled through this cooperative agreement (Table 1).
    During 2003, ATSDR announced a new five year cooperative agreement 
program with the MHPF. The purpose of the program is to apply findings 
from the previous ten year environmental health and Toxicology Research 
Program and to improve public health and environmental medicine in low-
income and minority communities. The new program builds on earlier 
efforts and expands the Program's public environmental health impact on 
affected communities. Activities across the following four research and 
environmental public health focus areas were funded to initiate this 
new program: substance-specific toxicology research, environmental 
exposure assessment, community-based environmental health education, 
and environmental health education for primary-care providers. No 
additional priority data needs are being addressed under this new 
program.
    To date, Program research findings and other activities have 
resulted in the publication of more than 50 manuscripts in peer-
reviewed journals. The institutions which have received awards and 
their respective studies 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 continues to collaborate with NTP to address priority data 
needs of mutual interest. Chemicals for which NTP has conducted studies 
(or is in the process of conducting studies) to fill ATSDR's priority 
data needs include carbon tetrachloride, 1,1-dichloroethene, di-n-butyl 
phthalate, disulfoton, and heptachlor (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 Fiscal Year 1992 the availability of $2 million for a 
grant

[[Page 71510]]

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 Human Health Effects Research 
Program have resulted in 70 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 which have received 
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 59 of the 60 priority substances (Table 1). In 
some cases, ATSDR anticipates obtaining 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. Regarding the priority data need for exposure 
subregistries, the list of the 60 priority hazardous substances in the 
SSARP was forwarded to ATSDR's 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. Currently, ATSDR has established exposure 
subregistries for benzene, dioxin, 1,1,1-trichloroethane (not included 
in the SSARP), trichloroethylene, and tremolite asbestos.

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 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 three years or sooner, as needed.

    Dated: November 17, 2005.
Kenneth Rose,
Acting Director, Office of Policy, Planning, and Evaluation, National 
Center for Environmental Health, Agency for Toxic Substances and 
Disease Registry.

          Table 1.--ATSDR's Substance-Specific Priority Data Needs for 60 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                                               2000 updated
                                               intermediate-                                     ATSDR
                                               duration oral                                     toxicological
                                               exposure.                                         profile.
                                1B..........  Bioavailability
                                               from soil.
                                1C..........  Exposure levels   ..............  ..............  This priority
                                               in humans                                         data need,
                                               living near                                       previously
                                               hazardous waste                                   addressed in a
                                               sites and 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.

[[Page 71511]]

 
                                2D..........  Exposure levels   G. Lakes......  Filled........  In addition to
                                               in humans                                         the data from
                                               living near                                       the Great Lakes
                                               hazardous waste                                   Research
                                               sites and other                                   Program,
                                               populations,                                      background
                                               such as exposed                                   level data are
                                               workers.                                          available in
                                                                                                 ATSDR's 1993
                                                                                                 toxicological
                                                                                                 profile, and at
                                                                                                 least seven
                                                                                                 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.
Asbestos......................  3A..........  Epidemiologic
                                               studies of
                                               individuals
                                               occupationally
                                               exposed to
                                               asbestos levels
                                               lower than
                                               those
                                               experienced
                                               before the
                                               institution of
                                               current
                                               occupational
                                               standards
                                               governing the
                                               use of
                                               asbestos, but
                                               higher than
                                               current levels
                                               in the general
                                               population.
                                               These studies
                                               should be
                                               performed in
                                               conjunction
                                               with the
                                               immunotoxicity
                                               studies.
                                3B..........  Immunotoxicity
                                               studies of
                                               individuals
                                               occupationally
                                               exposed to
                                               asbestos.
                                3C..........  Development of
                                               human and rat
                                               lung retention
                                               models to aid
                                               in
                                               extrapolating
                                               between rat and
                                               human data.
                                3D..........  Improved
                                               analytical
                                               methods for
                                               screening
                                               samples and
                                               determining the
                                               chemical
                                               structure of
                                               asbestos
                                               fibers. Also,
                                               techniques are
                                               needed to
                                               normalize
                                               studies in
                                               which different
                                               analytical
                                               methods were
                                               employed.
                                3E..........  Exposure levels,
                                               fiber size
                                               distribution,
                                               and asbestos
                                               fiber type in
                                               areas with
                                               natural
                                               geologic
                                               deposits of
                                               friable
                                               asbestos and at
                                               hazardous waste
                                               sites. Also,
                                               techniques for
                                               estimating air
                                               levels of
                                               asbestos from
                                               soil
                                               concentrations
                                               and activity
                                               scenarios.
                                3F..........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites and in
                                               other
                                               populations,
                                               such as humans
                                               living in areas
                                               with naturally
                                               high levels of
                                               friable
                                               asbestos.
                                3G..........  Potential         ATSDR.........  Filled........  ATSDR
                                               candidate for                                     established
                                               subregistry of                                    registry to
                                               exposed persons.                                  follow the
                                                                                                 health of
                                                                                                 people who were
                                                                                                 exposed to
                                                                                                 asbestos in
                                                                                                 Libby, Montana.
                                                                                                 The name of the
                                                                                                 registry is the
                                                                                                 Tremolite
                                                                                                 Asbestos
                                                                                                 Registry (TAR).
Benzene.......................  4A..........  Dose-response     EPA...........  ..............  Reproductive
                                               data in animals                                   toxicity study
                                               for acute- and                                    is the only
                                               intermediate-                                     component of
                                               duration oral                                     this PDN that
                                               exposure. The                                     is included in
                                               subchronic                                        the EPA/ATSDR
                                               study should                                      test rule.
                                               include an
                                               extended
                                               reproductive
                                               organ
                                               histopathology.

[[Page 71512]]

 
                                4B..........  Prenatal          EPA...........  ..............  Previously
                                               developmental                                     planned study
                                               toxicity study                                    in the MHPF
                                               via oral                                          Research
                                               exposure.                                         Program to
                                                                                                 address this
                                                                                                 priority data
                                                                                                 need was
                                                                                                 canceled.
                                4C..........  Neurotoxicology   EPA...........
                                               battery of
                                               tests via oral
                                               exposure.
                                4D..........  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.
                                4E..........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               living near                                       are available
                                               hazardous waste                                   (Ashley et al.
                                               sites and 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.
Benzidine.....................  5A..........  Dose-response
                                               data for acute-
                                               and
                                               intermediate-
                                               duration
                                               exposure via
                                               the oral route
                                               (the study of
                                               intermediate-
                                               duration
                                               exposure should
                                               include
                                               evaluation of
                                               reproductive
                                               and endocrine
                                               organ
                                               histopathology,
                                               lymphoid
                                               tissues
                                               histopathology
                                               as well as
                                               examination of
                                               relevant blood
                                               components, and
                                               nervous system
                                               histopathology).
                                5B..........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites.
                                5C..........  Exposure levels
                                               in children.
                                5D..........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Beryllium.....................  6A..........  Dose-response     EPA...........
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration
                                               inhalation
                                               exposures. The
                                               subchronic
                                               study should
                                               include
                                               extended
                                               reproductive
                                               organ
                                               histopathology.
                                6B..........  Prenatal          EPA...........
                                               developmental
                                               toxicity study
                                               via inhalation
                                               exposure.
                                6C..........  Environmental     EPA...........
                                               fate in air;
                                               factors
                                               affecting
                                               bioavailability
                                               in air.
                                6D..........  Analytical        ..............  Filled........  Based on an
                                               methods to                                        evaluation of
                                               determine                                         the data in
                                               environmental                                     ATSDR's 2000
                                               speciation.                                       updated
                                                                                                 toxicological
                                                                                                 profile.
                                6E..........  Immunotoxicology  EPA...........
                                               battery of
                                               tests following
                                               oral exposure.

[[Page 71513]]

 
                                6F..........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               (adults) living                                   in urine are
                                               near hazardous                                    available
                                               waste sites and                                   (Paschal et al.
                                               other                                             1998, CDC
                                               populations,                                      2005). 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.
                                6G..........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in urine are
                                                                                                 available (CDC
                                                                                                 2005).
                                6H..........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Cadmium.......................  7A..........  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.
                                7B..........  Exposure levels   G. Lakes......  Filled........  In addition to
                                               in humans                                         the data from
                                               (adults) living                                   the Great Lakes
                                               near hazardous                                    Research
                                               waste sites and                                   Program,
                                               other                                             reference range
                                               populations,                                      concentrations
                                               such as exposed                                   in blood and
                                               workers.                                          urine are
                                                                                                 available (CDC
                                                                                                 2005), and at
                                                                                                 least nine
                                                                                                 ATSDR studies
                                                                                                 that evaluated
                                                                                                 blood and urine
                                                                                                 cadmium levels
                                                                                                 and potential
                                                                                                 adverse health
                                                                                                 effects are
                                                                                                 available.
                                7C..........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in blood and
                                                                                                 urine are
                                                                                                 available (CDC
                                                                                                 2005).
Carbon tetrachloride..........  8A..........  Dose-response
                                               data in animals
                                               for chronic
                                               oral exposure.
                                               The study
                                               should include
                                               extended
                                               reproductive
                                               organ and
                                               nervous tissue
                                               histopathology.
                                8B..........  Immunotoxicology  NTP...........  Filled........  NTP dose-finding
                                               battery of                                        study and one
                                               tests via oral                                    study in
                                               exposure.                                         ATSDR's 1994
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile
                                                                                                 addressed the
                                                                                                 priority data
                                                                                                 need.
                                8C..........  Half-life in      ..............  Filled........  One study in
                                               soil.                                             ATSDR's 1994
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile
                                                                                                 provided
                                                                                                 information on
                                                                                                 half-life in
                                                                                                 soil.
                                8D..........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               living near                                       in blood are
                                               hazardous waste                                   available
                                               sites and 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.
                                8E..........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Chlordane.....................  9A..........  Oral              MHPF..........  Filled........  Availability of
                                               multigeneration                                   studies in the
                                               al studies to                                     MHPF Research
                                               evaluate                                          Program.
                                               reproductive
                                               toxicity.
                                9B..........  Bioavailability
                                               studies
                                               following
                                               ingestion of
                                               contaminated
                                               media.

[[Page 71514]]

 
                                9C..........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               (adults) living                                   in serum are
                                               near hazardous                                    available (CDC
                                               waste sites and                                   2005). ATSDR
                                               other                                             acknowledges
                                               populations                                       that reference
                                               potentially                                       concentration
                                               exposed to                                        data can
                                               chlordane.                                        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.
                                9D..........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in serum are
                                                                                                 available (CDC
                                                                                                 2005).
                                9E..........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Chlorinated dibenzo-p-dioxins   10A.........  Studies via oral
 (CDDs).                                       exposure
                                               designed to
                                               assess
                                               childhood
                                               susceptibility.
                                10B.........  Comparative
                                               toxicokinetic
                                               studies
                                               examining the
                                               relative
                                               absorption of
                                               CDDs across
                                               exposure routes
                                               and the
                                               relative
                                               contribution of
                                               each exposure
                                               route to total
                                               body burdens.
                                10C.........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               (adults) living                                   in serum are
                                               near hazardous                                    available (CDC
                                               waste sites.                                      2005). 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.
                                10D.........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in serum are
                                                                                                 available (CDC
                                                                                                 2005).
Chloroethane..................  11A.........  Dose-response     EPA...........
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration or
                                               exposures. The
                                               subchronic
                                               study should
                                               include an
                                               evaluation of
                                               immune and
                                               nervous system
                                               tissues, and
                                               extended
                                               reproductive
                                               organ
                                               histopathology.
                                ............  Dose-response     EPA...........
                                               data in animals
                                               for chronic
                                               inhalation
                                               exposure.s The
                                               study should
                                               include an
                                               evaluation of
                                               nervous system
                                               tissues.
                                11C.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Chloroform....................  12A.........  Dose-response     ..............  Filled........  An MRL was
                                               data in animals                                   derived in
                                               for                                               ATSDR's 1997
                                               intermediate-                                     updated
                                               duration oral                                     toxicological
                                               exposure.                                         profile.
                                ............  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                                      data as they
                                               and                                               become
                                               developmental                                     available to
                                               toxicity,                                         determined if
                                               hepatotoxicity,                                   additional
                                               and renal                                         studies are
                                               toxicity).                                        needed.

[[Page 71515]]

 
                                12C.........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               living near                                       in blood are
                                               hazardous waste                                   available
                                               sites and 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.
                                12D.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Chromium......................  13A.........  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.
                                13B.........  Multigeneration   EPA...........
                                               reproductive
                                               toxicity study
                                               via oral
                                               exposure to
                                               chromium (III)
                                               and (VI).
                                13C.........  Immunotoxicology  EPA...........
                                               battery of
                                               tests following
                                               oral exposure
                                               to chromium
                                               (III) and (VI).
                                13D.........  Prenatal          EPA...........
                                               developmental
                                               toxicity study
                                               via oral
                                               exposure to
                                               chromium (III)
                                               and (VI).
                                13E.........  Exposure levels   G. Lakes......  Filled........  In addition to
                                               in humans                                         the data from
                                               living near                                       the Great Lakes
                                               hazardous waste                                   Research
                                               sites and other                                   Program,
                                               populations,                                      reference range
                                               such as exposed                                   concentrations
                                               workers.                                          in urine are
                                                                                                 available
                                                                                                 (Paschal et al.
                                                                                                 1998). Also, at
                                                                                                 least two STSDR
                                                                                                 studies that
                                                                                                 evaluated urine
                                                                                                 chromium levels
                                                                                                 and potential
                                                                                                 adverse health
                                                                                                 effects are
                                                                                                 available.
Cynaide.......................  14A.........  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
                                               neuropathologic
                                               al end points.
                                14B.........  Prenatal          EPA...........
                                               developmental
                                               toxicity study
                                               via oral
                                               exposure.
                                14C.........  Evaluation of     ..............  Filled........  A study
                                               the                                               addressing the
                                               environmental                                     priority data
                                               fate of cyanide                                   need was
                                               in soil.                                          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.
                                14D.........  Exposure levels   ..............  ..............  ................
                                               in humans
                                               living near
                                               hazardous waste
                                               sites and other
                                               populations,
                                               such as exposed
                                               workers.
                                14E.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
1,2-dibromo-3-chloropropane...  15A.........  Dose-response
                                               data in animals
                                               for acute-
                                               duration
                                               exposure via
                                               the oral route
                                               (including
                                               reproductive
                                               organ
                                               histopathology).

[[Page 71516]]

 
                                15B.........  Dose-response
                                               data in animals
                                               for chronic-
                                               duration
                                               exposure via
                                               the oral route
                                               (including
                                               reproductive
                                               organ
                                               histopathology).
                                15C.........  Prenatal
                                               developmental
                                               toxicity study
                                               via oral
                                               exposure.
                                15D.........  Immunotoxicology  ..............  ..............  Previously
                                               testing battery                                   planned study
                                               via oral                                          in the MHPF
                                               exposure.                                         Research
                                                                                                 Program to
                                                                                                 address this
                                                                                                 priority data
                                                                                                 need was
                                                                                                 canceled.
                                15E.........  Neurotoxicology   ..............  ..............  Previously
                                               testing battery                                   planned study
                                               via oral                                          in the MHPF
                                               exposure.                                         Research
                                                                                                 Program to
                                                                                                 address this
                                                                                                 priority data
                                                                                                 need was
                                                                                                 canceled.
                                15G.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
1,2-Dibromoethane.............  16A.........  Dose-response
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration
                                               exposure by the
                                               oral route (the
                                               study of
                                               intermediate-
                                               duration
                                               exposure should
                                               include
                                               evaluation of
                                               neuropathology
                                               and observation
                                               for overt signs
                                               of
                                               neurotoxicity).
                                16B.........  Multigeneration
                                               reproductive
                                               toxicity
                                               studies via
                                               oral exposure.
                                16C.........  Developmental
                                               toxicity
                                               studies via
                                               oral exposure.
                                16D.........  Immunotoxicity
                                               battery studies
                                               via oral
                                               exposure.
                                16E.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites and in
                                               other
                                               populations,
                                               such as workers
                                               exposed to 1, 2-
                                               dibromoethane.
                                16F.........  Exposure levels
                                               in children.
                                16G.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
1,2-Dichloroethane............  17A.........  Dose-response
                                               data in animals
                                               for acute-
                                               duration (14-
                                               day) exposure
                                               by the
                                               inhalation
                                               route,
                                               including a
                                               comparison of
                                               young and adult
                                               animals.
                                17B.........  Dose-response
                                               data in animals
                                               for acute-
                                               duration (14-
                                               day) exposure
                                               by the oral
                                               route,
                                               including a
                                               comparison of
                                               young and adult
                                               animals.
                                17C.........  Dose-response
                                               data in animals
                                               for
                                               intermediate-
                                               duration
                                               exposure by the
                                               inhalation
                                               route (the
                                               study should be
                                               performed in
                                               conjunction
                                               with the
                                               neurotoxicology
                                               battery of
                                               tests).
                                17D.........  Neurotoxicology
                                               battery of
                                               tests following
                                               inhalation
                                               exposure.
                                17E.........  Neurotoxicology
                                               battery of
                                               tests following
                                               oral exposure.
                                17F.........  Dose-response
                                               data in animals
                                               for chronic-
                                               duration
                                               exposure by the
                                               oral route.
                                17G.........  Prenatal
                                               developmental
                                               toxicity data
                                               for inhalation
                                               exposure
                                               (assessment of
                                               developmental
                                               cardiotoxicity
                                               and
                                               neurotoxicity).

[[Page 71517]]

 
                                17H.........  Prenatal
                                               developmental
                                               toxicity data
                                               for oral
                                               exposure
                                               (assessment of
                                               developmental
                                               cardiotoxicity
                                               and
                                               neurotoxicity).
                                17I.........  Additional
                                               analyses and
                                               studies for
                                               comparative
                                               toxicokinetics
                                               across species,
                                               ages, routes,
                                               and durations >.
                                17J.........  Children's
                                               susceptibility.
                                17K.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites.
                                17L.........  Exposure levels
                                               in children.
                                17M.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
1,1-Dichloroethene............  18A.........  Dose-response     NTP...........  Filled........  Availability of
                                               data in animals                                   ongoing NTP
                                               for acute-                                        study.
                                               duration
                                               exposure by the
                                               inhalation
                                               route.
                                18B.........  Dose-response     NTP...........  Filled........  Availability of
                                               data in animals                                   ongoing NTP
                                               for chronic-                                      study.
                                               duration
                                               exposure by the
                                               inhalation
                                               route.
                                18C.........  Dose-response
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration
                                               exposure by the
                                               oral route.
                                18D.........  Carcinogenicity
                                               studies in two
                                               species
                                               following
                                               inhalation
                                               exposure.
                                18E.........  Reproductive
                                               toxicity
                                               studies
                                               assessing male
                                               and female end
                                               points
                                               following
                                               inhalation
                                               exposure.
                                18F.........  Prenatal
                                               developmental
                                               toxicity
                                               studies
                                               following oral
                                               exposure.
                                18G.........  Immunotoxicology
                                               battery of
                                               tests following
                                               oral exposure.
                                18H.........  Battery of
                                               neurobehavioral
                                               tests following
                                               inhalation
                                               exposure.
                                18I.........  Children's
                                               susceptibility.
                                18J.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites.
                                18K.........  Exposure levels
                                               in children.
                                18L.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
DDT...........................  19A.........  Dose-response
                                               data in animals
                                               for chronic-
                                               duration oral
                                               exposure.
                                19B.........  Comparative
                                               toxicokinetic
                                               study (across
                                               routes/species).
                                19C.........  Bioavailability
                                               and
                                               bioaccumulation
                                               from soil.
                                19D.........  Epidemiologic     G. Lakes......  Filled........  In addition to
                                               studies on the                                    the data from
                                               health of DDT,                                    the Great Lakes
                                               DDD, and DDE                                      Research
                                               (Special                                          Program,
                                               emphasis end                                      multiple
                                               points include                                    studies in
                                               immunotoxicity,                                   ATSDR's 2000
                                               and                                               updated
                                               reproductive                                      toxicological
                                               and                                               profile are
                                               developmental                                     available.
                                               toxicity).

[[Page 71518]]

 
                                19E.........  Exposure levels   G. Lakes......  Filled........  In addition to
                                               in humans                                         the data from
                                               (adults) living                                   the Great Lakes
                                               near hazardous                                    Research
                                               waste sites and                                   Program,
                                               other                                             reference range
                                               populations,                                      concentrations
                                               such as exposed                                   in serum are
                                               workers.                                          available (CDC
                                                                                                 2005). 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.
                                19F.........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in serum are
                                                                                                 available (CDC
                                                                                                 2005).
                                19G.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Di (2-ethylhexyl) phthalate...  20A.........  Epidemiologic
                                               studies on the
                                               health effects
                                               of DEHP
                                               (Special
                                               emphasis end
                                               points include
                                               cancer).
                                20B.........  Dose-response     ..............  ..............  This research
                                               data in animals                                   need remains as
                                               for acute- and                                    a priority data
                                               intermediate-                                     need because
                                               duration oral                                     the previously
                                               exposures. The                                    developed MRL
                                               subchronic                                        for acute-
                                               study should                                      duration (1993
                                               include an                                        toxicological
                                               extended                                          profile) was
                                               histopathologic                                   withdrawn.
                                               evaluation of                                     However, a new
                                               the immunologic                                   MRL for
                                               and neurologic                                    intermediate-
                                               systems.                                          duration was
                                                                                                 derived in
                                                                                                 ATSDR's 2002
                                                                                                 updated
                                                                                                 Toxicological
                                                                                                 Profile.
                                                                                                 Therefore, this
                                                                                                 priority data
                                                                                                 need is
                                                                                                 considered
                                                                                                 partially
                                                                                                 filled because
                                                                                                 additional
                                                                                                 adequate acute-
                                                                                                 duration data
                                                                                                 for deriving an
                                                                                                 MRL are still
                                                                                                 lacking.
                                20C.........  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 2002
                                                                                                 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.
                                20D.........  Comparative       ..............  Filled........  The existing
                                               toxicokinetic                                     database
                                               studies                                           provides
                                               (Studies                                          adequate
                                               designed to                                       information to
                                               examine how                                       fill this
                                               primates                                          priority data
                                               metabolize and                                    need based on
                                               distribute DEHP                                   ATSDR's
                                               as compared                                       reevaluation of
                                               with rodents                                      the published
                                               via oral                                          data.
                                               exposure).
                                20E.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites and other
                                               populations,
                                               such as exposed
                                               workers.
                                20F.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed
                                               persons..
Di-n-butyl phtalate...........  21A.........  Dose-response     NTP...........  Filled........  Availability of
                                               data in animals                                   an NTP study.
                                               for acute-
                                               duration
                                               exposure via
                                               the oral route.
                                21B.........  Dose-response
                                               data in animals
                                               for chronic-
                                               duration
                                               exposure via
                                               the oral route.
                                21C.........  Carcinogenicity
                                               studies via
                                               oral exposure.

[[Page 71519]]

 
                                21D.........  In vivo           MHPF..........  Filled........  Availability of
                                               genotoxicity                                      a study in the
                                               studies.                                          MHPF Research
                                                                                                 Program
                                21E.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites and other
                                               populations,
                                               such as exposed
                                               workers.
                                21F.........  Environmental
                                               fate of di-n-
                                               butyl phthalate
                                               in
                                               environmental
                                               media.
                                21G.........  Bioavailability
                                               in contaminated
                                               environmental
                                               media near
                                               hazardous waste
                                               sites.
                                21H.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed
                                               persons..
Disulfoton....................  22A.........  Immunotoxicology  NTP...........  Filled........  Availability of
                                               testing battery                                   ongoing NTP
                                               following oral                                    study.
                                               exposure.
                                22B.........  Exposure levels
                                               of disulfoton
                                               in tissues/
                                               fluids for
                                               populations
                                               living near
                                               hazardous waste
                                               sites and other
                                               populations,
                                               such as exposed
                                               workers.
                                22C.........  Disulfoton        ATSDR.........
                                               should be
                                               considered as a
                                               potential
                                               candidate for a
                                               subregistry of
                                               exposed persons.
Endosulfan ([alpha], [beta],    23A.........  Acute-duration
 and sulfate).                                 oral exposure
                                               studies.
                                23B.........  Data on
                                               sensitive
                                               neurologic end
                                               point following
                                               oral exposure.
                                23C.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites and other
                                               populations,
                                               such as exposed
                                               workers.
                                23D.........  Data on the
                                               bioavailability
                                               of endosulfan
                                               from soil.
                                23E.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Endrin/endrin aldehyde........  24A.........  Dose-response
                                               animal data for
                                               acute oral
                                               exposure to
                                               endrin.
                                24B.........  Multigeneration
                                               reproductive
                                               toxicity
                                               studies via
                                               oral exposure
                                               to endrin.
                                24C.........  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.
                                24D.........  Exposure levels
                                               for endrin and
                                               its degradation
                                               products in
                                               humans living
                                               near hazardous
                                               waste sites.
                                24E.........  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.
                                24F.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Ethylbenzene..................  25A.........  Dose-response
                                               data for acute-
                                               duration
                                               exposure by the
                                               inhalation
                                               route.
                                25B.........  Dose-response
                                               data for
                                               chronic-
                                               duration
                                               exposure by the
                                               inhalation
                                               route.

[[Page 71520]]

 
                                25C.........  Dose-response
                                               data for acute-
                                               and
                                               intermediate-
                                               duration
                                               exposure by the
                                               oral route; the
                                               study of
                                               intermediate-
                                               duration
                                               exposure should
                                               include an
                                               evaluation of
                                               clinical signs
                                               of
                                               neurotoxicity
                                               and
                                               histopathology
                                               of reproductive
                                               organs,
                                               endocrine
                                               glands, and
                                               nervous system.
                                25D.........  Multigeneration
                                               toxicity study
                                               examining
                                               reproductive
                                               end points and
                                               indicators of
                                               endocrine
                                               disruption
                                               following
                                               inhalation
                                               exposure.
                                25E.........  Prenatal
                                               developmental
                                               study with
                                               continued
                                               assessment of
                                               offspring
                                               during
                                               postnatal
                                               development
                                               following oral
                                               exposure.
                                25F.........  Studies for
                                               comparative
                                               toxicokinetics.
                                25G.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites.
                                25H.........  Exposure levels
                                               in children.
                                25I.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Heptachlor/heptachlor epoxide.  26A.........  Dose-response
                                               animal data for
                                               acute- and
                                               intermediate-
                                               duration oral
                                               exposures,
                                               including
                                               immunopathology.
                                26B.........  Multigeneration   NTP...........  Filled........  Availability of
                                               reproductive                                      publication
                                               toxicity                                          ``The effects
                                               studies via the                                   of perinatal/
                                               oral route of                                     juvenile
                                               exposure.                                         heptachlor
                                                                                                 exposure on
                                                                                                 adult immune
                                                                                                 and
                                                                                                 reproductive
                                                                                                 system function
                                                                                                 in rats'' by
                                                                                                 Smialowicz et
                                                                                                 al. (2001),
                                                                                                 Toxicological
                                                                                                 Sciences 61:164-
                                                                                                 175.
                                26C.........  Prenatal          ..............  Filled........  Based on ATSDR's
                                               developmental                                     review of the
                                               toxicity                                          literature,
                                               studies via the                                   i.e.,
                                               oral route of                                     Smialowicz et
                                               exposure.                                         al. (2001),
                                                                                                 Toxicological
                                                                                                 Sciences 61:164-
                                                                                                 175 and Moser
                                                                                                 et al. (2001)
                                                                                                 Toxicological
                                                                                                 Sciences 60
                                                                                                 (2):315-326.
                                26D.........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               (adults) living                                   in serum are
                                               near hazardous                                    available (CDC
                                               waste sites and                                   2005). ATSDR
                                               other                                             acknowledges
                                               populations,                                      that reference
                                               such as exposed                                   concentration
                                               workers.                                          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.
                                26E.........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in serum are
                                                                                                 available (CDC
                                                                                                 2005).
                                26F.........  Bioavailability
                                               from
                                               contaminated
                                               air, water, and
                                               soil and
                                               bioaccumulation
                                               potential.
                                26G.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Hexachlorobutadiene...........  27A.........  Dose-response
                                               data in animals
                                               for acute-
                                               duration
                                               exposure via
                                               the oral route.

[[Page 71521]]

 
                                27B.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites and other
                                               populations,
                                               such as exposed
                                               workers.
                                27C.........  Environmental
                                               fate studies
                                               that determine
                                               the extent to
                                               which hexa
                                               chloro but
                                               adiene
                                               volatilizes
                                               from soil, and
                                               studies that
                                               determine the
                                               reactions and
                                               rates which
                                               drive
                                               degradation in
                                               soil.
                                27D.........  Bioavailability
                                               studies in soil
                                               and plants.
                                27E.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Hexachlorocyclohexane           28A.........  Dose-response     ..............  Filled........  An MRL was
 ([alpha], [beta] and [gamma]).                data for                                          derived in
                                               chronic-                                          ATSDR's 1999
                                               duration oral                                     updated
                                               exposure.                                         toxicological
                                                                                                 profile.
                                28B.........  Mechanistic
                                               studies on the
                                               neurotoxicity,
                                               hepatotoxicity,
                                               reproductive
                                               toxicity, and
                                               immunotoxicity
                                               of
                                               hexachlorocyclo
                                               hexane.
                                28C.........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               (adults) living                                   in serum are
                                               near hazardous                                    available (CDC
                                               waste sites and                                   2005). ATSDR
                                               other                                             acknowledges
                                               populations,                                      that reference
                                               such as exposed                                   concentration
                                               workers.                                          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.
                                28D.........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in serum are
                                                                                                 available (CDC
                                                                                                 2005).
                                28E.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Lead..........................  29A.........  Mechanistic       MHPF..........  Filled........  Multiple studies
                                               studies on the                                    (at least 13
                                               neurotoxic                                        publications
                                               effects of lead.                                  from the MHPF
                                                                                                 Research
                                                                                                 Program +
                                                                                                 numerous
                                                                                                 studies in
                                                                                                 ATSDR's 1999
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile) are
                                                                                                 available.
                                29B.........  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.
                                29C.........  Exposure levels   MHPF, G. Lakes  Filled........  In addition to
                                               in humans                                         the data from
                                               (adults) near                                     Great Lakes
                                               hazardous waste                                   Research
                                               sites and other                                   Program and
                                               populations,                                      MHPF Research
                                               such as exposed                                   Program,
                                               workers.                                          reference range
                                                                                                 concentrations
                                                                                                 in blood and
                                                                                                 urine are
                                                                                                 available (CDC
                                                                                                 2005; Paschal
                                                                                                 et al. 1998),
                                                                                                 and at least 19
                                                                                                 ATSDR studies
                                                                                                 that evaluated
                                                                                                 blood lead
                                                                                                 levels and
                                                                                                 potential
                                                                                                 adverse health
                                                                                                 effects are
                                                                                                 available.
                                29D.........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in blood and
                                                                                                 urine are
                                                                                                 available (CDC
                                                                                                 2005).

[[Page 71522]]

 
Manganese.....................  30A.........  Dose-response     MHPF, EPA.....  Filled........  Availability of
                                               data for acute-                                   studies in the
                                               and                                               MHPF Research
                                               intermediate-                                     Program.
                                               duration oral
                                               exposures (the
                                               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
                                               hypersensitivit
                                               y reactions).
                                30B.........  Toxicokinetic     MHPF, EPA.....  Filled........  Availability of
                                               studies on                                        studies in the
                                               animals to                                        MHPF Research
                                               investigate                                       Program.
                                               uptake and
                                               absorption,
                                               relative uptake
                                               of differing
                                               manganese
                                               compounds,
                                               metabolism of
                                               manganese, and
                                               interaction of
                                               manganese with
                                               other
                                               substances
                                               following oral
                                               exposure.
                                30C.........  Epidemiological   ..............  Filled........  Based on an
                                               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,                                      become
                                               and cancer).                                      available to
                                                                                                 determine if
                                                                                                 additional
                                                                                                 studies are
                                                                                                 needed.
                                30D.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites and other
                                               populations,
                                               such as exposed
                                               workers.
                                30E.........  Relative          EPA.
                                               bioavailability
                                               of different
                                               manganese
                                               compounds and
                                               bioavailability
                                               of manganese
                                               from soil.
Mercury.......................  31A.........  Multigeneration   MHPF..........  Filled........  Availability of
                                               reproductive                                      publications
                                               toxicity study                                    from the MHPF
                                               via oral                                          Research
                                               exposure.                                         Program.
                                31B.........  Dose-response     ..............  Filled........  An MRL was
                                               data in animals                                   derived in
                                               from chronic-                                     ATSDR's 1999
                                               duration oral                                     updated
                                               exposure.                                         toxicological
                                                                                                 profile.
                                31C.........  Immunotoxicology  EPA.
                                               battery of
                                               tests via oral
                                               exposure.
                                31D.........  Exposure levels   G. Lakes......  Filled........  In addition to
                                               in humans                                         the data from
                                               (adults) living                                   the Great Lakes
                                               near hazardous                                    Research
                                               waste sites and                                   Program,
                                               other                                             background
                                               populations,                                      levels data are
                                               such as exposed                                   available in
                                               workers.                                          ATSDR's 1997
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile, and
                                                                                                 multiple ATSDR
                                                                                                 studies that
                                                                                                 evaluated
                                                                                                 blood, urine,
                                                                                                 hair mercury
                                                                                                 levels and
                                                                                                 potential
                                                                                                 adverse health
                                                                                                 effects are
                                                                                                 available.
                                                                                                 Also, reference
                                                                                                 range
                                                                                                 concentrations
                                                                                                 in blood and
                                                                                                 urine are
                                                                                                 available (CDC
                                                                                                 2005).
                                31E.........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in blood and
                                                                                                 urine are
                                                                                                 available (CDC
                                                                                                 2005).
                                31F.........  Potential         ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
Methoxychlor..................  32A.........  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.
                                32B.........  Exposure levels
                                               of methoxychlor
                                               and primary
                                               metabolites in
                                               humans living
                                               near hazardous
                                               waste sites and
                                               those
                                               individuals
                                               with the
                                               potential to
                                               ingest it..

[[Page 71523]]

 
                                32C.........  Evaluate the
                                               fate,
                                               transport, and
                                               levels of the
                                               degradation
                                               products of
                                               methoxychlor in
                                               soil..
                                32D.........  Potential         ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
Methylene chloride............  33A.........  Dose-response     EPA, Vol Res..  Filled........  ATSDR accepted
                                               data in animals                                   HSIA's toxicity
                                               for acute- and                                    study for acute-
                                               intermediate-                                      and
                                               duration oral                                     intermediate-
                                               exposure. The                                     duration
                                               subchronic                                        exposure
                                               study should                                      duration in
                                               include                                           February 1997.
                                               extended                                          Also, ATSDR
                                               reproductive                                      accepted HSIA's
                                               organ                                             immunotoxicity
                                               histopathology,                                   study via
                                               neuropathology,                                   inhalation in
                                               and                                               November 2000
                                               immunopathology.                                  and the oral
                                                                                                 data obtained
                                                                                                 via PBPK
                                                                                                 modeling
                                                                                                 conducted by
                                                                                                 HSIA based on
                                                                                                 the
                                                                                                 immunotoxicity
                                                                                                 data from the
                                                                                                 inhalation
                                                                                                 study.
                                                                                                 Neurotoxicity
                                                                                                 screening
                                                                                                 battery testing
                                                                                                 remains in the
                                                                                                 ATSDR/EPA test
                                                                                                 rule under
                                                                                                 development.
                                33B.........  Prenatal          Vol Res.......  Filled........  ATSDR accepted
                                               developmental                                     HSIA's study in
                                               toxicity study                                    February 1997.
                                               via the oral
                                               route.
                                33C.........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               living near                                       in blood are
                                               hazardous waste                                   available
                                               sites and 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.
                                33D.........  Potential         ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
Nickel........................  34A.........  Epidemilogic      ..............  Filled........  Based on at
                                               studies on the                                    least two
                                               health effects                                    relevant
                                               of nickel                                         studies in
                                               (Special                                          ATSDR's 1997
                                               emphasis end                                      updated
                                               points include                                    toxicological
                                               reproductive                                      profile. ATSDR
                                               toxicity).                                        will continue
                                                                                                 to evaluate new
                                                                                                 data as they
                                                                                                 become
                                                                                                 available to
                                                                                                 determine if
                                                                                                 additional
                                                                                                 studies are
                                                                                                 needed.
                                34B.........  Prenatal          EPA...........  Filled........  In ATSDR's 1997
                                               development                                       updated
                                               toxicity study                                    toxicological
                                               via the oral                                      profile, a
                                               route.                                            study
                                                                                                 confirming the
                                                                                                 results of two
                                                                                                 previous
                                                                                                 studies is
                                                                                                 available.
                                34C.........  Dose-response     EPA.
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration oral
                                               exposures.
                                34D.........  Neurotoxicology   EPA.
                                               battery of
                                               tests via oral
                                               exposure.
                                34E.........  Bioavailability   EPA.
                                               of nickel from
                                               soil.
                                34F.........  Exposure levels   G. Lakes......  Filled........  Based on
                                               in humans                                         availability of
                                               (adults) living                                   the data from
                                               near hazardous                                    the Great Lakes
                                               waste sites and                                   Research
                                               other                                             Program and an
                                               populations,                                      evaluation of
                                               such as exposed                                   ATSDR's 1997
                                               workers.                                          updated
                                                                                                 toxicological
                                                                                                 profile.
                                34G.........  Potential         ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
Pentachlorophenol.............  35A.........  Comparative
                                               toxicokinetic
                                               studies..

[[Page 71524]]

 
                                35B.........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               (adults) living                                   in urine are
                                               near hazardous                                    available (CDC
                                               waste sites.                                      2005. 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.
                                35C.........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in urine are
                                                                                                 available (CDC
                                                                                                 2005).
                                35D.........  Potential         ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
Polychlorinated biphenyls       36A.........  Dose-response     G. Lakes......  ..............  Although an MRL
 (PCBs).                                       data in animals                                   for
                                               for acute- and                                    intermediate-
                                               intermediate-                                     exposure
                                               duration oral                                     duration was
                                               exposure.                                         derived in
                                                                                                 ATSDR's 2000
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile, an MRL
                                                                                                 for acute-
                                                                                                 exposure
                                                                                                 duration is
                                                                                                 still lacking.
                                36B.........  Biodegradation
                                               of PCBs in
                                               water;
                                               bioavailability
                                               of PCBs in air,
                                               water, and
                                               soil..
                                36C.........  Dose-response
                                               data in animals
                                               for acute- and
                                               intermediate-
                                               duration
                                               inhalation
                                               exposures. The
                                               subchronic
                                               study should
                                               include
                                               extended
                                               reproductive
                                               organ
                                               histopathology..
                                36D.........  Epidemiologic     G. Lakes......  Filled........  In addition to
                                               studies on the                                    the data from
                                               health effects                                    the Great Lakes
                                               of PCBs                                           Research
                                               (Special                                          Program,
                                               emphasis end                                      multiple
                                               points include                                    studies in
                                               immunotoxicity,                                   ATSDR's 2000
                                               gastrointestina                                   updated
                                               l toxicity,                                       toxicological
                                               liver toxicity,                                   profile are
                                               kidney                                            available.
                                               toxicity,
                                               thyroid
                                               toxicity, and
                                               reproductive/
                                               developmental
                                               toxicity).
                                36E.........  Exposure levels   G. Lakes......  Filled........  In addition to
                                               in humans                                         the data from
                                               (adults) living                                   the Great Lakes
                                               near hazardous                                    Research
                                               waste sites and                                   Program,
                                               other                                             background
                                               populations,                                      levels data are
                                               such as exposed                                   available
                                               workers.                                          (ATSDR's 1997
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profile,
                                                                                                 Needham et al.
                                                                                                 1996, and CDC
                                                                                                 2005). Also,
                                                                                                 multiple ATSDR
                                                                                                 studies that
                                                                                                 evaluated blood
                                                                                                 and breast milk
                                                                                                 PCB levels and
                                                                                                 potential
                                                                                                 adverse health
                                                                                                 effects are
                                                                                                 available.
                                36F.........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in serum are
                                                                                                 available (CDC
                                                                                                 2005).
                                36G.........  Potential         ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
                                36H\5\......  Chronic toxicity  Vol Res.......  Filled........  ATSDR accepted
                                               and                                               the final
                                               oncogenicity                                      report of the
                                               via oral                                          GE study in
                                               exposure.                                         October 1997.
                                36I\5\......  Aerobic PCB       Vol Res.......  Filled........  ATSDR accepted
                                               biodegradation                                    the final
                                               in sediment.                                      report of the
                                                                                                 GE study in
                                                                                                 July 1999.
                                36J\5\......  PCB congener      Vol Res, G.     Filled........  ATSDR accepted
                                               analysis.         Lakes.                          the final
                                                                                                 report of the
                                                                                                 GE study in
                                                                                                 October 1997.
                                                                                                 Also, data from
                                                                                                 the Great Lakes
                                                                                                 Research
                                                                                                 Program are
                                                                                                 available.

[[Page 71525]]

 
Polycyclic aromatic             37A.........  Dose-response     MHPF..........  Filled........  MRLs for four
 hydrocarbons (PAHs) (Includes                 data in animals                                   PAHs were
 15 substances).                               for                                               derived in
                                               intermediate-                                     ATSDR's 1995
                                               duration oral                                     updated
                                               exposures. The                                    toxicological
                                               subchronic                                        profile. A
                                               study should                                      publication
                                               include                                           from the MHPF
                                               extended                                          Research
                                               reproductive                                      Program
                                               organ                                             addressing this
                                               histopathology                                    priority data
                                               and                                               need is
                                               immunopathology.                                  available.
                                37B.........  Prenatal          MHPF..........  Filled........  Data from the
                                               developmental                                     MHPF Research
                                               toxicity study                                    Program
                                               via inhalation                                    including a
                                               or oral                                           publication are
                                               exposure.                                         available.
                                37C.........  Mechanistic       MHPF..........  Filled........  In addition to
                                               studies on                                        publications
                                               PAHs, on how                                      from the MHPF
                                               mixtures of                                       Research
                                               PAHs can                                          Program,
                                               influence the                                     studies are
                                               ultimate                                          available in
                                               activation of                                     ATSDR's 1995
                                               PAHs, and on                                      updated
                                               how PAHs affect                                   toxicological
                                               rapidly                                           profile.
                                               proliferating
                                               tissues..
                                37D.........  Dose-response     MHPF..........  Filled........  Data from the
                                               data in animals                                   MHPF Research
                                               for acute- and                                    Program
                                               intermediate-                                     including one
                                               duration                                          publication are
                                               inhalation                                        available.
                                               exposures. The
                                               subchronic
                                               study should
                                               include
                                               extended
                                               reproductive
                                               organ
                                               histopathology
                                               and
                                               immunopathology.
                                37E.........  Epidemiologic     ..............  Filled........  Multiple studies
                                               studies on the                                    in ATSDR's 1995
                                               health effects                                    updated
                                               of PAHs                                           toxicological
                                               (Special                                          profile are
                                               emphasis end                                      available.
                                               points include                                    ATSDR will
                                               cancer, dermal,                                   continue to
                                               hemolymphatic,                                    evaluate new
                                               and hepatic                                       data as they
                                               toxicity).                                        become
                                                                                                 available to
                                                                                                 determine if
                                                                                                 additional
                                                                                                 studies are
                                                                                                 needed.
                                37F.........  Exposure levels   G. Lakes......  Filled........  Based on data
                                               in humans                                         from the Great
                                               (adults) living                                   Lakes Research
                                               near hazardous                                    Program and an
                                               waste sites and                                   evaluation of
                                               other                                             the ATSDR 1995
                                               populations,                                      updated
                                               such as exposed                                   toxicological
                                               workers.                                          profile. Also,
                                                                                                 reference range
                                                                                                 concentrations
                                                                                                 in urine are
                                                                                                 available (CDC
                                                                                                 2005). The
                                                                                                 Agency
                                                                                                 continues to
                                                                                                 recognize the
                                                                                                 importance of
                                                                                                 collecting
                                                                                                 additional data
                                                                                                 on uniquely
                                                                                                 exposed
                                                                                                 populations at
                                                                                                 waste sites.
                                37G.........  Exposure levels   ..............  Filled........  Reference range
                                               in children.                                      concentrations
                                                                                                 in urine are
                                                                                                 available (CDC
                                                                                                 2005).
                                37H.........  Potential         ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
Selenium......................  38A.........  Dose-response     EPA.
                                               data in animals
                                               for EPA acute-
                                               duration oral
                                               exposure.
                                38B.........  Immunotoxicology  EPA.
                                               battery of
                                               tests via oral
                                               exposure.
                                38C.........  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                                      data as they
                                               and                                               become
                                               developmental                                     available to
                                               toxicity,                                         determine if
                                               hepatotoxicity,                                   additional
                                               and adverse                                       studies are
                                               skin effects).                                    needed.

[[Page 71526]]

 
                                38D.........  Exposure levels   G. Lakes......  Filled........  In addition to
                                               in humans                                         the data from
                                               living near                                       the Great Lakes
                                               hazardous waste                                   Research
                                               sites and other                                   Program,
                                               populations,                                      reference range
                                               such as exposed                                   concentrations
                                               workers.                                          in serum are
                                                                                                 available
                                                                                                 (NHANES III).
                                                                                                 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.
                                38E.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
1,1,2,2-Tetrachloroethane.....  39A.........  Prenatal
                                               developmental
                                               toxicity study
                                               by the oral
                                               route.
                                39B.........  Immunotoxicity
                                               battery
                                               following oral
                                               exposure.
                                39C.........  Mammalian in
                                               vivo
                                               genotoxicity
                                               assays.
                                39D.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites.
                                39E.........  Exposure levels
                                               in children.
                                39F.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Tetrachloroethylene...........  40A.........  Dose-response     ..............  Filled........  An MRL was
                                               data in animals                                   derived in the
                                               for acute-                                        ATSDR 1997
                                               duration oral                                     updated
                                               exposure,                                         toxicological
                                               including                                         profile.
                                               neuropathology
                                               and demeanor,
                                               and
                                               immunopathology.
                                40B.........  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 will
                                                                                                 obtain the oral
                                                                                                 data from the
                                                                                                 inhalation
                                                                                                 study by
                                                                                                 conducting PBPK
                                                                                                 modeling.
                                40C.........  Dose-response     EPA, Vol Res..  ..............  HSIA will obtain
                                               data in animals                                   oral data for
                                               for                                               intermediate-
                                               intermediate-                                     duration
                                               duration oral                                     toxicity and
                                               exposure,                                         neurotoxicity
                                               including                                         by PBPK
                                               neuropathology,                                   modeling based
                                               and                                               on existing
                                               immunopathology.                                  inhalation
                                                                                                 data. Also, it
                                                                                                 will conduct an
                                                                                                 inhalation
                                                                                                 immunotoxicity
                                                                                                 study, followed
                                                                                                 by PBPK
                                                                                                 modeling to
                                                                                                 obtain oral
                                                                                                 data.
                                40D.........  Prenatal          Vol Res.......  ..............  HSIA's
                                               developmental                                     developmental
                                               toxicity study                                    toxicity study
                                               via oral                                          via inhalation
                                               exposure.                                         was accepted by
                                                                                                 ATSDR. However,
                                                                                                 ATSDR has
                                                                                                 identified
                                                                                                 ingestion of
                                                                                                 contaminated
                                                                                                 environmental
                                                                                                 media to be the
                                                                                                 primary
                                                                                                 exposure route
                                                                                                 for this
                                                                                                 chemical at
                                                                                                 waste sites.
                                                                                                 HSIA will
                                                                                                 obtain the oral
                                                                                                 data from the
                                                                                                 inhalation
                                                                                                 study by
                                                                                                 conducting PBPK
                                                                                                 modeling.
                                40E.........  Developmental     EPA, Vol Res..
                                               neurotoxicity
                                               study via oral
                                               exposure.

[[Page 71527]]

 
                                40F.........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               living near                                       in blood are
                                               hazardous waste                                   available
                                               sites and 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.
                                40G.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Toluene.......................  41A.........  Dose-response     ..............  Filled........  Availability of
                                               data in animals                                   MRLs for acute-
                                               for acute- and                                    and
                                               intermediate-                                     intermediate-
                                               duration oral                                     exposure
                                               exposures. The                                    durations in
                                               subchronic                                        ATSDR's 2000
                                               study should                                      updated
                                               include an                                        toxicological
                                               extended                                          profile.
                                               histopathologic
                                               evaluation of
                                               the immune
                                               system.
                                41B.........  Comparative       ..............  Filled........  Based on
                                               toxicokinetic                                     evaluation of
                                               studies                                           the data in
                                               (Characterizati                                   ATSDR's 2000
                                               on of                                             updated
                                               absorption,                                       toxicological
                                               distribution,                                     profile.
                                               and excretion
                                               via oral
                                               exposure).
                                41C.........  Neurotoxicology   EPA, MHPF.....  ..............  A publication
                                               battery of                                        for acute
                                               tests via oral                                    exposure but
                                               exposure.                                         not longer term
                                                                                                 exposure is
                                                                                                 available in
                                                                                                 the MHPF
                                                                                                 Research
                                                                                                 Program. Also,
                                                                                                 this priority
                                                                                                 data need is
                                                                                                 included in the
                                                                                                 EPA/ATSDR test
                                                                                                 rule.
                                41D.........  Mechanism of      ..............  Filled........  Multiple studies
                                               toluene-induced                                   in ATSDR's 1994
                                               neurotoxicity.                                    and 2000
                                                                                                 updated
                                                                                                 toxicological
                                                                                                 profiles are
                                                                                                 available.
                                41E.........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               living near                                       in blood are
                                               hazardous waste                                   available
                                               sites and other                                   (Ashley et al.
                                               populations,                                      1992, 1994;
                                               such as exposed                                   Needham et al.
                                               workers.                                          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.
                                41F.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.
Toxaphene.....................  42A.........  Identify the
                                               long-term
                                               health
                                               consequences of
                                               exposure to
                                               environmental
                                               toxaphene via
                                               oral exposure.
                                42B.........  Conduct
                                               additional
                                               immunotoxicity
                                               studies for
                                               chronic-
                                               duration via
                                               oral route of
                                               exposure.
                                42C.........  Conduct
                                               additional
                                               neurotoxicity
                                               studies for
                                               chronic-
                                               duration via
                                               oral route of
                                               exposure.
                                42D.........  Exposure levels
                                               in humans
                                               living in areas
                                               near hazardous
                                               waste sites
                                               with toxaphene
                                               and in those
                                               individuals
                                               with the
                                               potential to
                                               ingest it.
                                42E.........  Potential         ATSDR.........
                                               candidate for
                                               subregistry of
                                               exposed persons.

[[Page 71528]]

 
Trichloroethylene.............  43A.........  Dose-response     ..............  Filled........  An MRL was
                                               data in animals                                   derived in
                                               for acute-                                        ATSDR's 1997
                                               duration oral                                     updated
                                               exposure.                                         toxicological
                                                                                                 profile.
                                43B.........  Neurotoxicology   EPA, MHPF, Vol  ..............  A publication
                                               battery of        Res.                            for acute
                                               tests via the                                     exposure but
                                               oral route.                                       not longer term
                                                                                                 exposure is
                                                                                                 available in
                                                                                                 the MHPF
                                                                                                 Research
                                                                                                 Program. Also,
                                                                                                 this priority
                                                                                                 data need is
                                                                                                 included in the
                                                                                                 EPA/ATSDR test
                                                                                                 rule and
                                                                                                 ATSDR's
                                                                                                 Voluntary
                                                                                                 Research
                                                                                                 Program.
                                43C.........  Immunotoxicology  Vol Res.......  ..............  HSIA has
                                               battery of                                        completed an
                                               tests via oral                                    inhalation
                                               route.                                            immunotoxicity
                                                                                                 study which is
                                                                                                 undergoing
                                                                                                 ATSDR peer
                                                                                                 review. HSIA
                                                                                                 will obtain
                                                                                                 oral data via
                                                                                                 PBPK modeling
                                                                                                 based on the
                                                                                                 inhalation
                                                                                                 data.
                                43D.........  Prenatal          Vol Res.......  ..............  ATSDR has
                                               developmental                                     accepted HSIA's
                                               toxicity study                                    final report
                                               via oral                                          for an
                                               exposure.                                         inhalation
                                                                                                 developmental
                                                                                                 toxicity study.
                                                                                                 HSIA will use
                                                                                                 PBPK modeling
                                                                                                 to obtain data
                                                                                                 for oral
                                                                                                 exposure based
                                                                                                 on the results
                                                                                                 of its
                                                                                                 inhalation
                                                                                                 study.
                                43E.........  Developmental     EPA, Vol Res..
                                               neurotoxicity
                                               study via oral
                                               exposure.
                                43F.........  Epidemiologic     ..............  Filled........  Based on
                                               studies on the                                    evaluation of
                                               health effects                                    the data in
                                               of                                                ATSDR's 1997
                                               trichloroethyle                                   updated
                                               ne (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.
                                43G.........  Exposure levels   ..............  Filled........  Reference range
                                               in humans                                         concentrations
                                               living near                                       in blood are
                                               hazardous waste                                   available
                                               sites and 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................  44A.........  Dose-response     ..............  Filled........  An MRL was
                                               data in animals                                   derived in
                                               for acute-                                        ATSDR's 1997
                                               duration                                          updated
                                               inhalation                                        toxicological
                                               exposure.                                         profile.
                                44B.........  Multigeneration   Vol Res.......  Filled........  ATSDR accepted
                                               reproductive                                      the final
                                               toxicity study                                    report of ACC's
                                               via inhalation.                                   study in
                                                                                                 November 2000.
                                44C.........  Dose-response
                                               data in animals
                                               for chronic-
                                               duration
                                               inhalation
                                               exposure..
                                44D.........  Mitigation of
                                               vinyl chloride-
                                               induced
                                               toxicity.
                                44E.........  Prenatal          Vol Res.......  Filled........  ATSDR accepted
                                               developmental                                     the final
                                               toxicity study                                    report of ACC's
                                               via inhalation.                                   study in
                                                                                                 November 2000.
                                44F.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites and other
                                               populations,
                                               such as exposed
                                               workers..
                                44G.........  Potential         ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.

[[Page 71529]]

 
Xylenes.......................  45A.........  Dose-response
                                               data for
                                               chronic-
                                               duration
                                               exposure by the
                                               oral route.
                                               This study
                                               should be done
                                               in conjunction
                                               with the
                                               neurotoxicology
                                               battery of
                                               tests.
                                45B.........  Neurotoxicology
                                               battery of
                                               tests following
                                               oral exposure..
                                45C.........  Two-generation
                                               reproductive
                                               study following
                                               oral exposure..
                                45D.........  Developmental
                                               toxicity study
                                               that includes
                                               neurodevelopmen
                                               tal end points
                                               following oral
                                               exposure..
                                45E.........  Exposure levels
                                               in humans
                                               living near
                                               hazardous waste
                                               sites..
                                45F.........  Exposure levels
                                               in children..
                                45G.........  Potential         ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
Zinc..........................  46A.........  Dose-response     MHPF..........  Filled........  Availability of
                                               data in animals                                   ongoing studies
                                               for acute- and                                    in the MHPF
                                               intermediate-                                     Research
                                               duration oral                                     Program.
                                               exposures. The
                                               subchronic
                                               study should
                                               include an
                                               extended
                                               histopathologic
                                               evaluation of
                                               the immunologic
                                               and neurologic
                                               systems.
                                46B.........  Multigeneration   MHPF..........  Filled........  Availability of
                                               reproductive                                      ongoing studies
                                               toxicity study                                    in the MHPF
                                               via oral                                          Research
                                               exposure.                                         Program.
                                46C.........  Carcinogenicity
                                               testing (2-year
                                               bioassay) via
                                               oral exposure..
                                46D.........  Exposure levels   ..............  ..............  This priority
                                               in humans                                         data need,
                                               living near                                       previously
                                               hazardous waste                                   anticipated to
                                               sites and other                                   be addressed
                                               populations,                                      under the
                                               such as exposed                                   voluntary
                                               workers.                                          research
                                                                                                 program, is not
                                                                                                 being
                                                                                                 investigated
                                                                                                 under any of
                                                                                                 the ATSDR
                                                                                                 research
                                                                                                 programs.
                                46E.........  Potential         ATSDR.
                                               candidate for
                                               subregistry of
                                               exposed persons.
----------------------------------------------------------------------------------------------------------------
\1\ Priority data need identification number.
\2\ Programs addressing priority data needs. ATSDR = ATSDR's Division of Health Studies; EPA = U.S.
  Environmental Protection Agency; G. Lakes = Great Lakes Human Health Effects Research Program; MHPF = Minority
  Health Professions Foundation; 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; MRL =
  Minimal Risk Level; CDC 2005 = The third National Report on Human Exposure to Environmental Chemicals,
  prepared by the National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta,
  GA; 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 Which Are Addressing/Have Addressed ATSDR's Substance-Specific Priority Data Needs (PDNs)
----------------------------------------------------------------------------------------------------------------
                                      Firm, institution,
              Program               agency, or consortium        Substance                    PDN ID
----------------------------------------------------------------------------------------------------------------
Voluntarism.......................  American Chemistry     Vinyl Chloride......  44B, 44E
                                     Council.
                                    General Electric       PCBs................  36H*, 36I*, 36J*
                                     Company.
                                    Halogenated Solvents   Methylene chloride..  33A, 33B
                                     Industry Alliance,
                                     Inc..
                                                           Tetrachloroethylene.  40B, 40C, 40D, 40E
                                                           Trichloroethylene...  43B, 43C, 43D, 43E
Minority Health Professions         Florida A & M          Lead................  29A
 Foundation.                         University.

[[Page 71530]]

 
                                    The King/Drew Medical  Lead................  29B, 29C
                                     Center of the
                                     Charles R. Drew
                                     University of
                                     Medicine and Science.
                                    Meharry Medical        PAHs................  37A, 37B, 37C, 37D
                                     College.
                                    Morehouse School of    Lead................  29C
                                     Medicine.
                                    Texas Southern         Di-n-butyl phthalate  21D
                                     University.
                                                           Lead................  29A
                                                           Toluene.............  41C
                                                           Trichloroethylene...  43B
                                    Tuskegee University..  Chlordane...........  9A
                                                           Mercury.............  31A
                                                           Zinc................  46A, 46B
                                    Xavier University....  Manganese...........  30A, 30B
                                                           Zinc................  46A
Great Lakes Human Health Effects    Michigan State         DDT/DDE.............  19D, 19E
 Research Program.                   University.
                                                           Lead................  29C
                                                           Mercury.............  31D
                                                           PCBs................  36D, 36E, 36J*
                                                           Selenium............  38D
                                    New York State Health  DDT/DDE.............  19E
                                     Department.
                                                           Lead................  29C
                                                           Mercury.............  31D
                                                           PCBs................  36D, 36E, 36J*
                                    State University of    PCBs................  36E
                                     New York at Albany.
                                    State University of    DDT/DDE.............  19D, 19E
                                     New York at Buffalo.
                                                           Lead................  29C
                                                           Mercury.............  31D
                                                           PCBs................  36D, 36E, 36J*
                                    State University of    DDT/DDE.............  19D, 19E
                                     New York at Oswego.
                                                           Lead................  29C
                                                           Mercury.............  31D
                                                           PCBs................  36D, 36E, 36J*
                                    University of          DDT/DDE.............  19D, 19E
                                     Illinois at Chicago.
                                                           Lead................  29C
                                                           Mercury.............  31D
                                                           PCBs................  36D, 36E, 36J*
                                    University of          DDT/DDE.............  19D, 19E
                                     Illinois at Urbana-
                                     Champaign.
                                                           Lead................  29C
                                                           Mercury.............  31D
                                                           PCBs................  36D, 36E, 36J*
                                    University of          DDT/DDE.............  19D, 19E
                                     Wisconsin-Milwaukee.
                                                           Lead................  29C
                                                           Mercury.............  31D
                                                           PCBs................  36A, 36D, 36E, 36J*
                                                           Selenium............  38D
                                    Wisconsin Department   Arsenic.............  2D
                                     of Health and Social
                                     Services--5 State
                                     Consortium.
                                                           Cadmium.............  7B
                                                           Chromium............  13E
                                                           DDT/DDE.............  19D, 19E
                                                           Lead................  29C
                                                           Mercury.............  31D
                                                           Nickel..............  34F
                                                           PAHs................  37F
                                                           PCBs................  36D, 36E, 36J*
Environmental Protection Agency     EPA/ATSDR Test Rule..  Benzene.............  4A, 4B, 4C
 TSCA/FIFRA.
                                                           Chloroethane........  11A, 11B
                                                           Cyanide (hydrogen     14A, 14B
                                                            cyanide and sodium
                                                            cyanide).
                                                           Methylene chloride..  33A
                                                           Tetrachloroethylene.  40C, 40E
                                                           Toluene.............  41C
                                                           Trichloroethylene...  43B, 43E

[[Page 71531]]

 
                                    Metals Testing Task    Arsenic.............  2A, 2B, 2C
                                     Force (TASARC).
                                                           Beryllium...........  6A, 6B, 6C, 6E
                                                           Chromium............  13A, 13B, 13C, 13D
                                                           Manganese...........  30A, 30B, 30E
                                                           Mercury.............  31C
                                                           Nickel..............  34B, 34C, 34D, 34E
                                                           Selenium............  38A, 38B
National Toxicology Program.......  National Institute of  Carbon tetrachloride  8B
                                     Carbon Environmental
                                     Health Sciences.
                                                           1,1-dichloroethene..  18A, 18B
                                                           Di-n-butyl phthalate  21A
                                                           Disulfoton..........  22A
                                                           Heptachlor..........  26B
----------------------------------------------------------------------------------------------------------------
* Not priority data needs.

[FR Doc. 05-23361 Filed 11-28-05; 8:45 am]
BILLING CODE 4163-70-P