[Federal Register Volume 82, Number 178 (Friday, September 15, 2017)]
[Notices]
[Pages 43354-43356]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-19703]
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ENVIRONMENTAL PROTECTION AGENCY
[EPA-HQ-OW-2016-0438; FRL-9967-69-OW]
Request for Public Comments To Be Sent to EPA on Peer Review
Materials To Inform the Safe Drinking Water Act Decision Making on
Perchlorate
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of request for public comment.
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SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing
the release of materials for public comment. These materials will
undergo expert peer review in support of EPA's Safe Drinking Water Act
decision making for perchlorate. This request is one of two Federal
Register notices being published concurrently, seeking public comment
on two separate sets of peer review materials. This notice requests
comments (to be sent to EPA) on a draft report entitled ``Draft Report:
Proposed Approaches to Inform the Derivation of a Maximum Contaminant
Level Goal for Perchlorate in Drinking Water'' (draft MCLG Approaches
Report). The companion notice requests comments (to be sent to EPA's
contractor, Versar, Inc.) on an interim list of peer reviewers and
draft charge questions.
DATES: Comments must be received by EPA on or before October 30, 2017.
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ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-
2016-0438 to the Federal eRulemaking Portal: http://www.regulations.gov. Follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or withdrawn. The
EPA may publish any comment received to its public docket. Do not
submit electronically any information you consider to be Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Multimedia submissions (audio, video, etc.) must
be accompanied by a written comment. The written comment is considered
the official comment and should include discussion of all points you
wish to make. The EPA will generally not consider comments or comment
contents located outside of the primary submission (i.e., on the web,
cloud, or other file sharing system). For additional submission
methods, the full EPA public comment policy, information about CBI or
multimedia submissions, and general guidance on making effective
comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.
FOR FURTHER INFORMATION CONTACT: For additional information concerning
the draft MCLG Approaches Report, please contact Samuel Hernandez at
U.S. EPA, Office of Ground Water and Drinking Water, Standards and Risk
Management Division, (Mail Code 4607M), 1200 Pennsylvania Avenue NW.,
Washington, DC 20460; telephone: 202-564-1735; or email:
[email protected].
SUPPLEMENTARY INFORMATION:
I. Information on EPA's Revised Biologically Based Dose-Response (BBDR)
Model
As a part of the national primary drinking water regulation (NPDWR)
development process for perchlorate, in accordance with the
requirements of the Safe Drinking Water Act, in 2012, EPA requested
comment from EPA's Science Advisory Board (SAB) prior to proposing an
MCLG and a NPDWR for perchlorate. EPA sought guidance on how best to
consider and interpret life stage information, epidemiologic and
biomonitoring data, physiologically-based pharmacokinetic analyses and
the totality of perchlorate health related information to derive a
perchlorate MCLG.
In 2013, the SAB recommended that, ``. . . EPA derive a perchlorate
MCLG that addresses sensitive life stages through physiologically-based
pharmacokinetic/pharmacodynamic (PBPK/PD) modeling based upon its mode
of action rather than the default MCLG approach using the reference
dose and specific chemical exposure parameters'' (Advice on Approaches
to Derive a Maximum Contaminant Level Goal for Perchlorate, EPA-SAB-13-
004).
Based on the SAB's recommendations, EPA, with contributions from
Food and Drug Administration scientists, developed a biologically based
dose response (BBDR) (also known as a PBPK/PD) model, to predict the
effects of perchlorate on serum thyroid hormone concentrations in
pregnant and lactating women exposed to perchlorate in drinking water
and in infants exposed via ingestion of perchlorate in formula or
breast milk.
On January 10 and 11, 2017, EPA's contractor (Versar, Inc.)
conducted an independent, scientific peer review of EPA's draft BBDR
model and draft model report. The purpose of the peer review was to
provide a documented, independent, and critical review of the draft
BBDR model and draft model report and to identify any necessary
improvements to the model prior to being finalized. On March 29, 2017,
EPA received the final peer review report entitled, ``External Peer
Review for EPA's Draft Biologically Based Dose-Response (BBDR) Model
and Draft BBDR Model Report for Perchlorate in Drinking Water,'' which
is available through the EPA docket at https://www.regulations.gov/docket?D=EPA-HQ-OW-2016-0439.
In developing the draft MCLG Approaches Report, EPA revised the
BBDR model to address those peer review recommendations that had the
greatest influence on the scientific rigor of the model and modeling
results. Those changes are described in the draft MCLG Approaches
Report. EPA will consider other peer review recommendations and public
comments in future revisions to the BBDR model and report.
II. Information on EPA's Draft Approaches To Inform the Derivation of a
Perchlorate MCLG
The SAB also recommended that EPA, ``utilize a mode of action (MOA)
framework for developing the MCLG that links the steps in the proposed
mechanism leading from perchlorate exposure through iodide uptake
inhibition to thyroid hormone changes and finally neurodevelopmental
impacts.''
EPA used the modeled thyroid hormone levels to predict potential
adverse health effects based on published epidemiology data
demonstrating a relationship between changes in thyroid hormone levels
and neurodevelopmental effects. This approach involved a focused review
of the literature connecting altered thyroid hormone levels to
neurodevelopmental outcomes for women in early pregnancy. EPA focused
on studies that provided a quantitative description of the relationship
between free thyroxine and neurodevelopment in infants and children
(e.g., intelligence quotient, verbal and problem solving skills and
motor coordination).
EPA will present an array of approaches to inform the derivation of
an MCLG for perchlorate for expert peer review. Using the revised BBDR
model output, EPA linked statistical relationships derived from five
studies to implement the MOA framework linking perchlorate exposure to
neurodevelopmental impacts. All five studies assess the relationship
between thyroid hormone levels in women in early pregnancy and various
neurodevelopmental effects on children at various ages. Two studies
assess the relationship on the IQ of children 5 to 10 years of age, two
other studies assess the relationship on Bayley Scales of Infant
Development of children 1 to 2 years of age, and a fifth study assesses
the relationship on reaction time of children 5 to 6 years of age. An
additional approach uses the revised BBDR model output to predict the
percent change in the population of hypothyroxinemic (or the low-end of
normal thyroid hormone levels) pregnant women due to perchlorate
exposure.
III. How To Obtain the Draft MCLG Approaches Report and Revised BBDR
Model
EPA's draft report entitled ``Draft Report: Proposed Approaches to
Inform the Derivation of a Maximum Contaminant Level Goal for
Perchlorate in Drinking Water'' is available electronically and can be
accessed using EPA's public docket at https://www.regulations.gov/docket?D=EPA-HQ-OW-2016-0438. The revised BBDR model code files can be
accessed at https://hero.epa.gov/hero/index.cfm/reference/details/reference_id/3352518. All written comments must be submitted during the
public comment period.
IV. Exclusion for Peer Review Candidates
Important: Anyone wishing to be considered as an expert peer
reviewer must not submit comments during the public comment period.
Candidates on the interim list not selected for the
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panel peer review (see companion Peer Review Federal Register notice,
published on September 15, 2017) will be given a limited opportunity to
submit public comments once the final peer reviewers are selected by
Versar, Inc., the EPA contractor managing this peer review process.
Dated: September 6, 2017.
Michael H. Shapiro,
Acting Assistant Administrator, Office of Water.
[FR Doc. 2017-19703 Filed 9-14-17; 8:45 am]
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