[Federal Register Volume 64, Number 10 (Friday, January 15, 1999)]
[Notices]
[Pages 2760-2790]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-971]



[[Page 2759]]

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Part VI





Department of Health and Human Services





_______________________________________________________________________



Agency for Toxic Substances and Disease Registry



_______________________________________________________________________



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

  Federal Register / Vol. 64, No. 10 / Friday, January 15, 1999 /
Notices  

[[Page 2760]]



DEPARTMENT OF HEALTH AND HUMAN SERVICES

Agency for Toxic Substances and Disease Registry
[ATSDR-140]


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

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

ACTION: Notice.

-----------------------------------------------------------------------

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 1996 (61 FR 14420). 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 (62 FR 61332, November 17, 1997), 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.
    To date, 124 priority data needs have been identified for the first 
set of 38 hazardous substances, and 64 priority data needs have been 
identified for the second set of 12 hazardous substances. ATSDR fills 
these data needs through regulatory mechanisms (test rules), private-
sector voluntarism, and the direct use of CERCLA funds. Additional data 
needs are being addressed through an interagency agreement with the 
National Toxicology Program (NTP), by ATSDR's Great Lakes Human Health 
Effects Research Program, and other agency programs. To date, 79 
priority data needs associated with the first set of 38 priority 
substances (Table 1), and 23 priority data needs associated with the 
second set of 12 priority substances (Table 2) are being addressed via 
these mechanisms.
    Table 1 also shows the progress ATSDR has made in filling research 
needs for the first set of 38 hazardous substances. On the basis of 
criteria developed by ATSDR, 14 priority data needs and 2 data needs 
have been filled, 26 priority data needs have been reclassified as data 
needs, and 2 additional priority data needs and 1 data need are 
considered conditionally filled pending ATSDR peer review of the final 
reports.
    This Notice also serves as a continuous call for voluntary research 
proposals. Private-sector organizations may volunteer to conduct 
research to address specific priority data needs identified in this 
Notice by indicating their interest through submission of a letter of 
intent to ATSDR (see ADDRESSES section of this Notice). A Tri-Agency 
Superfund Applied Research Committee (TASARC) composed of scientists 
from ATSDR, NTP, and the Environmental Protection Agency (EPA), will 
review all proposed voluntary research efforts.

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

ADDRESSES: Private-sector organizations interested in volunteering to 
conduct research may write to Dr. William Cibulas, Chief, Research 
Implementation Branch, Division of Toxicology, ATSDR, 1600 Clifton 
Road, NE., Mailstop E-29, Atlanta, Georgia 30333. Information about 
pertinent ongoing or completed research that may fill priority data 
needs cited in this Notice should be similarly addressed.

FOR FURTHER INFORMATION CONTACT: Dr. William Cibulas, Chief, Research 
Implementation Branch, Division of Toxicology, ATSDR, 1600 Clifton 
Road, NE., Mailstop E-29, Atlanta, Georgia 30333, telephone 404-639-
6306.

SUPPLEMENTARY INFORMATION:

Background

    CERCLA as amended by SARA (42 U.S.C. 9604(i)) requires that ATSDR 
(1) jointly with the EPA, develop and prioritize a list of hazardous 
substances found at National Priorities List (NPL) sites, (2) prepare 
toxicological profiles for these substances, and (3) assure the 
initiation of a research program to address identified data needs 
associated with the substances. Before starting such a program, ATSDR 
will consider recommendations of the Interagency Testing Committee on 
the type of research that should be done. This committee was 
established under Section 4(e) of the Toxic Substances Control Act of 
1976 (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 to conduct comprehensive public health assessments of 
populations living near hazardous waste sites. We anticipate that 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. 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.
    On October 17, 1991, ATSDR announced the identification of the 
priority data needs for 38 priority hazardous substances (56 FR 52178), 
requested public comments, and invited private-sector organizations to 
volunteer to conduct research to address specific priority data needs. 
On November 16, 1992, the agency published a revised list of 117 
priority data needs for these hazardous substances (57 FR 54150). Since 
1992, the total number of priority

[[Page 2761]]

data needs for the 38 substances has increased from 117 to 124 because 
the database was reevaluated (Table 1). The 7 additional priority data 
needs consist of 5 substances now considered as candidates for 
subregistries of exposed persons (determined by the ATSDR Division of 
Health Studies; the priority data needs for nickel, PCBs, toluene, and 
zinc were added in 1996, and that for beryllium was added in 1998), and 
2 new priority data needs for trichloroethylene.
    Regarding the 2 additional priority data needs for 
trichloroethylene, the need for intermediate-duration oral exposure 
data resulted from the withdrawal of the corresponding minimal risk 
level (MRL, a health guidance value) from the 1997 ATSDR updated 
Toxicological Profile for Trichloroethylene (Table 1). The other new 
priority data need for trichloroethylene is for a 1-species 
developmental toxicity study with emphasis on developmental 
neurotoxicity. Recent reports in humans, together with findings in 
animals, suggest that developmental effects may be the most sensitive 
end point for trichloroethylene.
    Therefore, the proposed study may provide more definitive 
information on dose-response relationships for these effects and more 
fully characterize the potential for adverse health outcome in the 
developing fetus.
    Two additional changes from the 1992 list of priority data needs 
have been made for tetrachloroethylene. The priority data need for 
chronic-duration oral exposure data has been replaced by the need for 
intermediate-duration oral exposure data because of the withdrawal of 
the intermediate-duration oral MRL from the 1997 ATSDR updated 
Toxicological Profile for Tetrachloroethylene (Table 1). ATSDR 
considers it is more appropriate to obtain intermediate-duration data 
before assigning priority to the conduct of chronic-duration studies. 
With regard to the priority to obtain developmental toxicity data, the 
use of 1-species (instead of the previously recommended 2-species) in 
the study is now considered adequate based on reevaluation of the 
database.
    Table 1 also includes 3 PCB research needs that are not considered 
``priority'' but were filled via voluntary research (see PDN ID#s 7G, 
7H, and 7I).
    On July 30, 1997, 77 priority data needs for 12 additional priority 
hazardous substances were determined and announced in the Federal 
Register (62 FR 40820). At that time, the 77 priority data needs 
included the need to evaluate existing data on concentrations of all 12 
substances in environmental media at hazardous waste sites. The agency 
continues to recognize the need to collect, evaluate, and interpret 
such data, but no longer considers these ``priority.'' This is because 
a substantial amount of this information has already been collected 
through individual state programs and the EPA's CERCLA activities. 
Further, an ongoing effort at the agency is to evaluate the extant 
information from these programs to better characterize the need for 
additional site-specific information. Finally, during a recent 
reevaluation of potential candidates for subregistries of exposed 
persons conducted by ATSDR, manganese was removed from the candidate 
pool; consequently, this priority data need was reclassified as a data 
need. Therefore, the current total number of priority data needs 
associated with the second set of 12 priority substances is now 64 
(Table 2).
    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 substances under TSCA and 
by registrants under the Federal Insecticide, Fungicide, and 
Rodenticide Act of 1972 (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 regulatory 
mechanisms (TSCA/FIFRA), private-sector voluntarism, and the direct use 
of CERCLA funds.
    The TASARC, composed of scientists from ATSDR, NTP, and EPA has 
been set up to:
    (1) Advise ATSDR on the assignment of priorities for mechanisms to 
address data needs;
    (2) Coordinate knowledge of research activities to avoid 
duplication of research in other programs and under other authorities;
    (3) Advise ATSDR on issues of science related to substance-specific 
data needs; and
    (4) Maintain a scheduled forum that provides an overall review of 
the ATSDR SSARP.
    TASARC has met eight times since the initiation of the SSARP. It 
has guided referral of data needs to EPA and the associated development 
of test rules through TSCA. In addition, it has endorsed the proposals 
of several private-sector organizations to conduct voluntary research. 
Furthermore, TASARC has become a forum for other federal agencies to 
bring forth their research agenda. 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 it has endorsed the use of decision support 
methodologies such as physiologically based pharmacokinetic (PBPK) 
modeling and benchmark-dose modeling, where appropriate.
    Additional data needs are being addressed through an interagency 
agreement with NTP, by ATSDR's Great Lakes Human Health Effects 
Research Program, and other agency programs. To date, 79 priority data 
needs associated with the first set of 38 priority substances (Table 
1), and 23 priority data needs associated with the second set of 12 
priority substances (Table 2) are being addressed via these mechanisms.

Criteria for Evaluating Status of Priority Data Needs

    To update the activities covered under the SSARP, criteria for 
evaluating the status of the priority data needs were developed. Based 
on these criteria and the review of the current literature, a priority 
data need may be filled, reclassified as a data need, or unchanged. 
Further, during the literature review, new studies may be identified 
suggesting other effects of concern, such as those related to endocrine 
disruptors and children's health, which have not been included in the 
original list of priority data needs. In such cases, additional data 
needs or priority data needs may be added to the research agenda.
    The criteria for evaluating the status of the priority data needs 
are described below.

General Criteria

    1. A priority data need is filled:
     If a study, specifically designed to address a priority 
data need and conducted via any of the ATSDR implementation mechanisms, 
has been completed and published in a peer-reviewed journal, or has 
been accepted by ATSDR based on the recommendations of the agency's 
peer reviewers, or
     If an updated ATSDR toxicological profile or other recent 
review document contains relevant new (peer reviewed and publicly 
available) studies since the finalization of the priority data needs 
document; and it is generally agreed that a priority data need no 
longer exists.

    Note: Priority data needs documents that describe ATSDR's 
rationale for prioritizing research needs for each substance in 
Tables 1 and 2 are available. See ADDRESSES section of this Notice.


[[Page 2762]]


    2. A priority data need is reclassified as a data need:
     If an updated ATSDR toxicological profile or other recent 
review document contains relevant new (peer reviewed and publicly 
available) studies since the finalization of the priority data needs 
document; however, in the data needs section of the toxicological 
profile, a need for additional data to fully characterize the end point 
is still identified, or
     If a study addressing a priority data need has been 
reviewed by members of the Tri-Agency Superfund Applied Research 
Committee and it is agreed that a data need still exists although it is 
no longer a priority (See priority data need ``Evaluation of the 
environmental fate of cyanide in soil'' in Table 1), or
     For any substance whose overall rank on the ATSDR Priority 
List of Hazardous Substances falls below 275.
    3. A priority data need is unchanged:
     If no mechanism or information has been identified to 
address the priority data need, or
     If the ATSDR toxicological profile has not been updated 
since the finalization of the priority data needs document (Exception: 
See Section ``Specific Criteria'' for the priority data need ``Exposure 
levels in humans''), or
     If the priority data need is included in the ATSDR test 
rule under development, or
     If ongoing discussions between ATSDR and a private-sector 
organization indicate that the priority data need is a candidate to be 
addressed via the voluntary research program, or
     If a study, specifically designed to address a priority 
data need and conducted via any of the ATSDR implementation mechanisms, 
is ongoing.

Specific Criteria

    1. Priority data need, ``Inhalation and/or oral dose-response data 
for acute, intermediate, and/or chronic duration.''
    These priority data needs are filled if minimal risk levels (MRLs) 
have been derived in the updated ATSDR toxicological profile since the 
finalization of the priority data needs document. However, in certain 
cases where the database (from which an MRL is derived) is sparse, a 
data need may still be identified in the toxicological profile to 
increase the confidence in the MRL.
    2. Priority data need, ``Exposure levels in humans.''
    This priority data need is considered filled if there are reference 
range data (e.g., National Health and Nutrition Examination Survey 
[NHANES]) or generally agreed upon background population levels AND if 
there are current and adequate biomonitoring data for exposed 
populations associated with health effects (from published or ongoing 
studies).
    This priority data need is reclassified as a data need if only one 
of the following 2 criteria is met: (1) There are reference range data 
or generally agreed upon background population levels OR (2) if there 
are current and adequate biomonitoring data for exposed populations 
associated with health effects (from published or ongoing studies).
    3. Priority data need ``Mechanism of toxic action.''
    This priority data need is considered filled if there is scientific 
consensus indicating that the mechanism(s) of toxic action is well 
characterized.
    This priority data need is reclassified as a data need if an 
updated toxicological profile contains relevant new (peer reviewed and 
publicly available) studies since the finalization of the priority data 
needs document; however, the database may not be sufficient to achieve 
scientific consensus on the mechanism of toxic action.
    Based on the above criteria, the status of the research needs for 
the first set of 38 priority substances was evaluated (Table 1). To 
date, 14 priority data needs and 2 data needs have been filled, 26 
priority data needs have been reclassified as data needs, and 2 
additional priority data needs (Table 1, vinyl chloride, PDN ID #4B and 
4E) and 1 data need (Table 1, PCBs, PDN ID #7H) are considered 
conditionally filled pending ATSDR peer review of the final reports.

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, NTP, and EPA 
identified priority data needs for substances on the TSCA inventory of 
mutual interest to the federal programs. These data needs are being 
addressed through a program of toxicologic testing under TSCA according 
to established procedures and guidelines. On several occasions when 
ATSDR identified priority data needs for oral exposure, other agencies 
needed inhalation data. In response, ATSDR is considering proposals to 
conduct inhalation studies in conjunction with physiologically based 
pharmacokinetic (PBPK) studies in lieu of oral bioassays. ATSDR expects 
that inhalation data derived from these studies can be used with PBPK 
modeling to address its oral toxicity data needs. Currently, an EPA/
ATSDR test rule, under development, includes 7 ATSDR substances, i.e., 
benzene, chloroethane, cyanide (including hydrogen cyanide and sodium 
cyanide), methylene chloride, tetrachloroethylene, trichloroethylene, 
and toluene, and addresses 15 priority data needs (Table 3). The test 
rule was reviewed by ATSDR and is undergoing EPA final review. It will 
be available for public comment in the near future.
    TASARC has established an interagency task force on metals and has 
recently conducted a survey to assess federal agencies' needs for 
testing metals. Currently, the task force has agreed to examine at 
least 7 metals included in the ATSDR's SSARP (arsenic, beryllium, 
chromium, manganese, mercury, nickel, and selenium, associated with 22 
priority data needs) (Table 3). The EPA will solicit testing proposals 
for these metals and pursue test rule development for these metals at a 
later date.

B. Private-Sector Voluntarism

    As part of the SSARP, on February 7, 1992, ATSDR announced a set of 
proposed procedures for conducting voluntary research (57 FR 4758). 
Revisions based on public comments were published on November 16, 1992 
(57 FR 54160). Private-sector organizations were encouraged to 
volunteer to conduct research to address specific priority data needs.
    ATSDR currently has memoranda of understanding (MOUs) in place with 
the General Electric Company (GE), the Halogenated Solvents Industry 
Alliance (HSIA), and the Chemical Manufacturers Association (CMA) 
(Table 3). Through the voluntary research efforts of these 
organizations, 12 research needs for two classes of substances 
(polychlorinated biphenyl compounds [PCBs] and volatile organic 
compounds, including methylene chloride, tetrachloroethylene, 
trichloroethylene, and vinyl chloride) are being addressed (Table 3).
    Recently, the agency received a study protocol from the Counselors 
for Management, Inc., on behalf of a spectrum of the zinc industry 
which is considering to conduct research to address ATSDR's priority 
data needs for zinc. This represents the first study proposed by a 
private-sector organization to address priority data needs for a metal. 
Voluntary research covered under the three existing MOUs is described 
next.

[[Page 2763]]

General Electric Company

    In 1995, ATSDR entered into an MOU with GE. This marked the first 
time a private-sector organization had volunteered to conduct research 
to address data needs identified in ATSDR's SSARP. The MOU with GE 
covers two studies on PCBs: (1) ``An assessment of the chronic toxicity 
and oncogenicity of Aroclors 1016, 1242, 1254, and 1260 administered in 
diet to rats,'' including ``PCB congener analyses,'' and (2) 
``Metabolite detection as a tool for determining naturally occurring 
aerobic PCB biodegradation.'' While the above studies do not address 
ATSDR's priority data needs for PCBs, they do address other agency 
research needs for these substances.
    The agency accepted the final report for the first study (chronic 
toxicity and oncogenicity) in October 1997. The study provided an in-
depth understanding of the relative toxicity of the prevalent 
commercial mixtures of PCBs (Aroclor 1016, Aroclor 1242, Aroclor 1254, 
and Aroclor 1260) after long-term exposures. The investigators found 
exposure-related toxicity for all four Aroclors. Furthermore, the study 
includes characterization of PCB composition, tissue accumulation, and 
correlations with tumorigenicity in chronically dosed rats. With regard 
to the second GE study (aerobic PCB biodegradation), also covered under 
the MOU, the final report is being evaluated by ATSDR's peer reviewers. 
The acceptance of the final report will be based on the recommendations 
of the reviewers and GE's satisfactory response to the reviewers' 
comments.

Halogenated Solvents Industry Alliance (HSIA)

    In 1995, ATSDR entered into an MOU with HSIA covering studies to 
address three priority toxicity data needs for methylene chloride. The 
studies, ``Addressing priority data needs for methylene chloride with 
physiologically based pharmacokinetic modeling,'' evaluated acute- and 
subchronic-duration toxicity via oral exposures and developmental 
toxicity via oral exposure. The data were obtained by using 
physiologically based pharmacokinetic modeling.
    The final report for these studies, the first one to be completed 
under the voluntary research program, was accepted by the agency in 
February 1997. The HSIA studies indicated that adverse health effects 
on the central nervous system, liver, and the development of newborns 
may occur if people drink water containing high concentrations of 
methylene chloride (565 to 6,170 milligrams methylene chloride per 
liter of water). These amounts are much larger than what most people 
are exposed to in the environment. However, these amounts approach 
levels found at industrial sites and in waste waters (ATSDR's 
Toxicological Profile for Methylene Chloride, 1993). HSIA has also 
proposed to conduct an immunotoxicity assessment for methylene chloride 
via inhalation exposure. The agency expects to receive a study protocol 
from HSIA for peer review in the near future.
    In addition, ATSDR and HSIA are continuing negotiation to expand 
the existing MOU to include research on trichloroethylene and 
tetrachloroethylene.

Chemical Manufacturers Association (CMA)

    In 1996, ATSDR entered into an MOU with CMA covering two studies, 
``Vinyl chloride: Combined inhalation two-generation reproduction and 
developmental toxicity study in CD rats.'' Recently, the ATSDR peer 
review of the final report on the developmental toxicity study was 
completed. The final report for the reproductive toxicity study is 
undergoing ATSDR peer review. Acceptance of the final reports is based 
on the reviewers' recommendations and CMA's satisfactory response to 
the reviewers' comments.

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 501(c)(3) 
organization, the MHPF comprises 11 minority health professions 
schools. Its primary mission is to research the health problems that 
disproportionately affect poor and minority citizens. The purpose of 
this cooperative agreement is to address substance-specific data needs 
for priority hazardous substances identified by ATSDR. In addition, 
this agreement strengthens the environmental health research 
opportunities for scientists and students at MHPF member institutions 
and enhances existing disciplinary capacities to conduct research in 
toxicology and environmental health.
    In the first 5-year project period that concluded during FY 1997, 9 
priority data needs for 21 priority hazardous substances and 22 data 
needs for these and other substances were addressed. The MHPF has 
developed a report, ``Environmental Health and Toxicology Research 
Program: Meeting Environmental Health Challenges Through Research, 
Education, and Service,'' that describes the research findings and 
other successes from the first 5 years of the program. New research 
initiated in the second 5-year project period includes studies to 
address 10 additional priority data needs for chlordane, 1,2-dibromo-3-
chloropropane, di-n-butyl phthalate, lead, manganese, the polycyclic 
aromatic hydrocarbons (PAHs), and zinc, and another 8 data needs.
    To date, the MHPF activities have resulted in the publication of 21 
manuscripts in peer-reviewed journals. Findings from this program were 
presented at a symposium held in April 1997, in New Orleans. Also, 
these and other research findings from the program were featured in a 
special session during the 1998 annual meeting of the Society of 
Toxicology in Seattle. The institutions receiving awards and their 
respective research projects are listed in Table 3.

D. National Toxicology Program (NTP)

    ATSDR maintains an interagency agreement (IAG) with NTP to conduct 
toxicologic testing of substances identified at NPL sites. The studies 
determine levels of exposure that present a significant risk to humans 
of acute, subchronic, and chronic health effects. Often these studies 
include an assessment of the substance's ability to cause cancer, 
reproductive toxicity, and birth defects. The results of these studies 
are used by regulatory agencies, various environmental and industrial 
groups, and ATSDR to improve its ability to conduct public health 
assessments at NPL sites.
    Under this agreement, one toxicity priority data need identified in 
the SSARP (immunotoxicology study of carbon tetrachloride) was filled 
(Table 1). Research efforts to address reproductive toxicity data needs 
for chlordane, endrin, and heptachlor, the bioavailability of PCBs in 
soil, and dose-response data for di-n-butyl phthalate are also ongoing 
(Table 3).
    During FY 1993, the existing IAG was modified to include toxicity 
studies of ATSDR's priority hazardous substances via application of 
structure-activity relationship (SAR) techniques, PBPK modeling, and 
functional toxicity testing. The ATSDR-supported NTP studies in these 
areas are ongoing.

E. Great Lakes Human Health Effects Research Program

    Some of the priority data needs identified in the SSARP have been

[[Page 2764]]

independently identified as research needs through the ATSDR Great 
Lakes Human Health Effects Research Program, a separate research 
program.
    In support of the Great Lakes Critical Programs Act of 1990, ATSDR 
announced in FY 1992 the availability of $2 million for a grant program 
to conduct research on the potential for short-and long-term adverse 
health effects from consumption of contaminated fish from the Great 
Lakes basin. Research undertaken through this program is intended to 
build on and amplify the results of past and ongoing fish consumption 
research in the Great Lakes basin. The ATSDR-supported research 
projects focus on known high-risk populations to further define the 
human health consequences of exposure to persistent toxic substances 
(PTSs) identified in the Great Lakes basin. These at-risk populations 
include sport anglers, Native Americans, pregnant women, fetuses and 
nursing infants of mothers who consume contaminated Great Lakes fish, 
infants and children, the elderly, and the urban poor.
    To date, the research activities of the ATSDR Great Lakes research 
program have resulted in 22 manuscripts in peer-reviewed journals. An 
additional 13 manuscripts have been accepted for publication and will 
soon be in press. Research findings from this program have been 
presented at 8 international conferences and various scientific 
meetings and symposia.
    Currently, 13 priority data needs and 1 data need for 24 priority 
hazardous substances (including 15 PAHs) identified in the SSARP are 
being addressed through this program. The institutions receiving awards 
and their respective studies are listed in Table 3.

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 37 of the first set of 38 priority substances 
(Table 1). Similarly, this priority data need has been identified for 
all 12 of the second set of 12 priority substances. ATSDR will obtain 
this information through exposure and health effects studies, and 
through establishing and using substance-specific subregistries of 
people within the agency's National Exposure Registry who have 
potentially been exposed to these substances.
    The list of 50 priority hazardous substances in the SSARP was 
forwarded to ATSDR's Exposure and Disease Registry Branch (EDRB), 
Division of Health Studies, for consideration as potential candidates 
for subregistries of exposed persons, based on criteria described in 
its 1994 document, ``National Exposure Registry: Policies and 
Procedures Manual (Revised),'' Agency for Toxic Substances and Disease 
Registry, Public Health Service, U.S. Department of Health and Human 
Services, Atlanta, Georgia, NTIS Publication No. PB95-154571. To date, 
of the first set of 38 priority substances in the SSARP, ATSDR has 
selected benzene, chromium, and trichloroethylene as primary 
contaminants to establish subregistries in the National Exposure 
Registry. However, aldrin/dieldrin, beryllium, carbon tetrachloride, 
chloroethane, chloroform, cyanide, p,p'-DDT, DDE, DDD, di(2-
ethylhexyl)phthalate, mercury, methylene chloride, nickel, PAHs, PCBs, 
selenium, tetrachloroethylene, toluene, vinyl chloride, and zinc remain 
in the candidate pool and therefore continue to be classified as 
priority data needs. They will be considered for selection as primary 
contaminants during each selection process (Table 1). Arsenic, cadmium, 
and lead are not considered to be in the pool of candidate substances 
for an exposure registry at this time, and therefore, are not 
considered priority data needs. This decision will be reevaluated as 
more information on the chemicals and exposure sites become available.
    Regarding the second set of 12 priority substances, all of them 
were included in the candidate pool for establishment of exposure 
subregistries (i.e., priority data needs, published in the 1996 Federal 
Register Notice [61 FR 14430]). However, during a recent reevaluation 
of the database, manganese was removed from the candidate pool, and 
therefore, this priority data need for manganese has been reclassified 
as a data need, and is not included in Table 2.
    The results of the research conducted via the SSARP will be used 
for public health assessments and to reassess ATSDR's substance-
specific priority data needs. The agency expects to provide an update 
on the status of this research program every three years.

    Dated: January 11, 1999.
Georgi Jones,
Director, Office of Policy and External Affairs, Agency for Toxic 
Substances and Disease Registry.

BILLING CODE 4163-70-P

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[FR Doc. 99-971 Filed 1-14-99; 8:45 am]
BILLING CODE 4163-70-C