[Federal Register Volume 63, Number 188 (Tuesday, September 29, 1998)]
[Notices]
[Pages 51918-51919]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-26007]
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ENVIRONMENTAL PROTECTION AGENCY
[FRL-6170-1]
Nominations for Peer Reviewers for Perchlorate Toxicological
Review
AGENCY: U.S. Environmental Protection Agency (EPA).
ACTION: Request for nominations.
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SUMMARY: EPA's Office of Solid Waste and Emergency Response has
retained Research Triangle Institute, Inc. (RTI) to coordinate a
scientific peer review of the Toxicological Review document for
perchlorate, including the revised provisional reference dose (RfD),
cancer assessment and ecological assessment. The peer review workshop
is tentatively scheduled to be held in late 1998 or early 1999, in
Ontario, California, and will be open to members of the public as
observers. The peer review will be conducted in accordance with EPA's
1998 Peer Review Handbook, and is being organized to assist in
completing EPA's evaluation of the effects on human health and the
environment of perchlorate. RTI is seeking nominations of highly
qualified scientists with expertise in general toxicology, thyroid
function and toxicology, developmental toxicology, neurotoxicology,
immunotoxicology, pharmacology, genetic toxicology, medical
endocrinology with an emphasis on thyroid function, biostatistics,
assessment of risks due to non-cancer and cancer health effects, and
assessment of risks due to ecological effects. RTI will select
approximately 10 objective peer reviewers based upon demonstrated
expertise of the scientists and the need for balance in affiliation
among the peer reviewers. RTI will consider potential conflicts of
interest in screening nominees for suitability as peer reviewers. All
nominations will be carefully considered, but the source of peer
reviewer nominations will not be a factor in the selection of peer
reviewers and stakeholders are not guaranteed that any of their
nominees will be selected. The peer review will cover the protocols and
results of ongoing studies of perchlorate toxicity to human health and
the environment, as well as the Toxicological Review document,
including the revised provisional RfD, cancer assessment, and
ecological assessment for perchlorate prepared by EPA's National Center
for Environmental Assessment (NCEA).
DATES: Nominations for peer reviewers must be submitted by October 29,
1998. A detailed resume for each nominated scientist should be included
with the submission. The projected date for the peer review workshop is
late 1998 or early 1999, depending on the availability of the peer
reviewers.
ADDRESSES: Peer reviewer nominations should be sent to Susan Goldhaber
at Research Triangle Institute, Inc., P.O. Box 12194, Research Triangle
Park, North Carolina, 27709. Peer reviewer nominations may also be
submitted by facsimile at 919-541-7155, or by E-mail at sbg@rti.org.
The peer review workshop will be held in Ontario, California.
FOR FURTHER INFORMATION CONTACT: For technical and logistical inquires,
contact Susan Goldhaber, Research Triangle Institute, by telephone, at
919-541-5965, by facsimile, at 919-541-7155, or by E-mail, at
sbg@rti.org.
SUPPLEMENTARY INFORMATION:
Background
EPA is in the process of developing a toxicological review document
for perchlorate, including a revised provisional RfD, cancer
assessment, and ecological assessment. An RfD is an estimate of a daily
oral human exposure that will result in no deleterious noncancer
effects over a lifetime. Ideally, an RfD is based on an array of
endpoints that address potential toxicity during various critical life
stages, from developing fetus through adult and reproductive stages.
The noncancer, cancer and ecological assessments may be used to support
development of a health advisory and/or drinking water regulations and
cleanup decisions at hazardous waste sites. In accordance with EPA's
1998 Peer Review Handbook, a key step in the development of the
Toxicological Review document for perchlorate will be an external peer
review, in the form of a workshop, of the recently completed toxicity
studies, the Toxicological Review document, and the revised provisional
RfD, cancer assessment and ecological assessment in that document.
EPA's Superfund Technical Support Center issued a provisional RfD
for perchlorate in 1992 and a revised provisional RfD in 1995. The
provisional RfD values (1992 and 1995) were based on an acute study in
which
[[Page 51919]]
single doses of potassium perchlorate caused the release of iodide from
the thyroids of patients with Graves' Disease. The provisional RfD
values did not undergo internal Agency or external peer review. In
March of 1997 a peer review panel convened by an independent
organization, Toxicology Excellence for Risk Assessment (TERA),
determined that the health effects and toxicity data for perchlorate
were insufficient to generate a credible RfD for risk assessment
purposes. The reviewers were concerned that developmental toxicity,
notably neurological development due to hypothyroidism during
pregnancy, could be a critical effect of perchlorate that has not been
adequately examined in studies to date. They also concluded that
insufficient data were available on potential effects of perchlorate on
organs and tissues other than the thyroid.
New Health Effects/Toxicology Studies Underway
A set of toxicological and ecological studies is underway to
address key data gaps and provide a comprehensive database related to
the toxicity of perchlorate. The studies are being funded and overseen
by a variety of organizations with potential responsibility for
perchlorate contamination in the environment including the United
States Air Force, the National Aeronautics and Space Administration and
the Perchlorate Study Group (PSG).1
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\1\ The PSG is a consortium of defense contractors and
manufacturers including: Aerojet, Alliant Techsystems, American
Pacific/Western Electrochemical Company, Atlantic Research
Corporation, Kerr-McGee Chemical Corp. Lockheed Martin, Thiokol
Propulsion Group, and United Technologies Chemical Systems.
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To date, a 90-day subchronic oral study, a neurobehavioral
developmental toxicity study, and a genotoxicity study have been
completed. Currently ongoing studies include a segment II developmental
toxicity study, a two-generation reproductive toxicity study,
absorption, distribution, metabolism, and elimination (ADME) studies,
perchlorate mechanistic studies, and immunotoxicity studies.
Ecotoxicity studies in Daphnia, earthworms, lettuce and fathead minnow
are also being performed. The results of most of these studies will be
available for discussion in the Toxicological Review document and for
development of the revised RfD, cancer, and ecological assessment for
perchlorate.
The peer review will focus on the scientific data, methods, and
analyses, along with the assumptions and uncertainties that are
associated with the revised provisional RfD, cancer assessment, and
ecological assessment for perchlorate. Following the peer review
workshop, RTI will issue a report summarizing the workshop. EPA will
consider the results of the workshop prior to issuing the revised
Toxicological Review document for perchlorate. Although the completed
risk assessment will be one of the factors considered in making future
decisions regarding perchlorate contamination in the environment, these
decisions and other risk management issues will not be a part of the
peer review process.
Dated: September 23, 1998.
Timothy Fields, Jr.,
Acting Assistant Administrator, Office of Solid Waste and Emergency
Response.
[FR Doc. 98-26007 Filed 9-28-98; 8:45 am]
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