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Literature Search for 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) Dose-Response Studies for Use in an Upcoming Expert Panel Workshop

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[Federal Register: November 24, 2008 (Volume 73, Number 227)]
[Notices]
[Page 70999-71000]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24no08-73]

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ENVIRONMENTAL PROTECTION AGENCY
[FRL-8744-2; Docket ID No. EPA-HQ-ORD-2008-0789]

Literature Search for 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD)
Dose-Response Studies for Use in an Upcoming Expert Panel Workshop

AGENCY: Environmental Protection Agency.
ACTION: Notice; availability of a literature search, public review
period, and request for information.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing a
45-day public review and request for additional information on
available peer-reviewed literature for 2,3,7,8-tetrachlorodibenzo-p-
dioxin (TCDD) dose-response for use in human health risk assessment. An
initial literature search was conducted by EPA through an Interagency
Agreement with the Department of Energy's Argonne National Laboratory.
Results of this preliminary search are available via the dioxin Web
site http://www.epa.gov/ncea/dioxin. The public is invited to review
the preliminary literature search results and submit any additional
information, specifically peer-reviewed TCDD dose-response studies, to
EPA that are not already identified in the literature search. Please
submit any information in accordance with the instructions provided
below. It is requested that the full publication be provided to EPA if
possible. Results of this literature search will be used by scientists
from EPA and other scientists from outside of EPA in the conduct of a
scientific expert workshop, open to the public, to be held in
Cincinnati, Ohio, on February 18-20, 2009. This workshop will be
announced in a future Federal Register notice.
    This notice provides: (1) A link to the electronic list of recent
literature search results for TCDD dose-response; and (2) instructions
to the public for submitting additional scientific information
pertinent to TCDD dose-response assessment to EPA that is not already
identified in the literature search.

DATES: The 45-day public comment period begins November 24, 2008, and
ends January 8, 2009.

ADDRESSES: Please submit relevant scientific information, identified by
docket ID number EPA-HQ-ORD-2008-0789, online at 
http://www.regulations.gov (EPA's preferred method); by e-mail to
ord.docket@epa.gov; by mail to the Office of Environmental Information
(OEI) Docket (Mail Code: 2822T), U.S. Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001 or by hand
delivery or courier to the EPA Docket Center, EPA West, Room 3334, 1301
Constitution Ave., NW., Washington, DC, between 8:30 a.m. and 4:30 p.m.
Monday through Friday, excluding legal holidays. Please see
SUPPLEMENTARY INFORMATION below for detailed instructions.

FOR FURTHER INFORMATION CONTACT: For information and help on submitting
scientific information, please contact the OEI Docket by e-mail
(ord.docket@epa.gov), by phone (202-566-1752), or by fax (202-566-
1753). For information and help on accessing the Literature Search for
TCDD Dose-Response and for technical information, please contact Glenn
E. Rice, National Center for Environmental Assessment (Mail Code: MSA-
110), Office of Research and Development, U.S. Environmental Protection
Agency, Cincinnati, Ohio 45268; telephone: 513-569-7813; facsimile:
513-487-2539; or e-mail: rice.glenn@epa.gov.

SUPPLEMENTARY INFORMATION:

Background

    In 1991, EPA announced that it would conduct a scientific
reassessment of the potential health risks of exposure to dioxin and
related compounds. EPA's Science Advisory Board (SAB) first reviewed
the draft dioxin reassessment in 1995, and the document was revised to
address SAB comments. In 2000, the SAB reviewed the integrated summary,
risk characterization, and other information on toxic equivalency of
dioxin-like compounds. Reports of the findings and recommendations of
these SAB reviews are available on the SAB Web site at http://
www.epa.gov/sab (see reports EPA-SAB-EC-95-021 and EPA-SAB-EC-01-006).
    In 2003, EPA produced an external review draft of the multi-year
comprehensive reassessment of dioxin exposure and human health effects
(http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=87843). This draft
dioxin reassessment document, titled Exposure and Human Health
Reassessment of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) and Related
Compounds, consisted of three parts: (1) A scientific review of
information relating to sources and exposures to TCDD and other dioxins
in the environment; (2) detailed reviews of scientific information on
the health effects of TCDD, other dioxins, and dioxin-like compounds;
and (3) an integrated summary and risk

[[Page 71000]]

characterization for TCDD and related compounds.
    In 2004, EPA asked the National Research Council of the National
Academy of Sciences (NAS) to review the 2003 dioxin reassessment
document. The NAS was charged with reviewing ``EPA's modeling
assumptions (including those associated with dose-response curve and
points-of-departure dose ranges and associated likelihood estimates
identified for human health outcomes); EPA's quantitative uncertainty
analysis; and EPA's selection of studies as a basis for its assessments
and gaps in scientific knowledge.'' The NAS was also charged with
addressing two points of controversy: (1) The scientific evidence for
classifying dioxin as a human carcinogen; and (2) the validity of the
nonthreshold, low-dose, linear dose-response model and the cancer slope
factor calculated through the use of this model. In addition, EPA asked
the NAS to comment on the usefulness of toxic equivalency factors
(TEFs) and uncertainties associated with their use in risk assessment,
as well as the uncertainty associated with EPA's approach to analysis
of food sampling and human dietary intake data, taking into
consideration the Institute of Medicine's report, Dioxin and Dioxin-
like Compounds in the Food Supply: Strategies to Decrease Exposure. In
2006, the NAS published its review titled, Health Risks from Dioxin and
Related Compounds: Evaluation of the EPA Reassessment. The NAS
identified three areas that required substantial improvement to support
a scientifically robust risk characterization. These three areas were:
(1) Justification of approaches to dose-response modeling for cancer
and non-cancer endpoints; (2) transparency and clarity in selection of
key data sets for analysis; and (3) transparency, thoroughness, and
clarity in quantitative uncertainty analysis. The NAS provided EPA with
recommendations to address their key concerns. The full NAS report,
including recommendations, is available at http://books.nap.edu/
catalog.php?record_id=11688. Exit Disclaimer
    EPA is now beginning to prepare a response to the NAS review of the
2003 draft dioxin reassessment, and the development of this preliminary
Literature Search for TCDD Dose-Response is one of the first steps in
this process. EPA's response to the NAS review of the 2003 draft dioxin
reassessment will focus on understanding human dose-response for TCDD,
addressing both cancer and non-cancer endpoints. EPA's objective is to
address the key findings of the NAS review regarding health effects
associated with dioxin exposure, while maintaining transparency and
openness throughout the process and providing opportunity for public
participation and comment.
    To fully address the key concerns of the NAS, EPA will host a
scientific expert panel workshop that will include scientists and
experts from inside and outside of EPA. These experts will consider the
literature on TCDD dose-response and discuss key scientific issues
related to this subject area. The literature search results will be
used by these expert panelists to provide EPA with a list of the key
studies it should consider in its response to the NAS comments. This
workshop will be announced in the Federal Register the near future.
    The quantitative assessment of dioxin health effects is important
to EPA and other organizations with a high level of interest in the
health risks associated with dioxin exposures. EPA plans to conduct its
dioxin work in a transparent manner, with the active and open
involvement of both stakeholders and the public. EPA is initiating the
process by identifying and engaging with various groups with interest
and expertise in dioxin health effects assessment. To provide for
expert peer involvement and review, the SAB Staff Office has solicited
nominations of nationally recognized scientists for consideration of
membership on an SAB Panel to provide advice on EPA's reassessment of
the health risks from dioxin and related compounds (73 FR 61114).
    The broad scope of dioxin science will likely require various
workshops, consultations, and other discussions of the state of the
science. EPA may solicit input and seek technical advice at various
steps during its response to the NAS report. EPA commits to a general
principle of keeping such discussions open and public, including the
use of Federal Register notices in advance of conducting workshops and
releasing interim drafts for review. EPA also has an internet site for
posting progress reports and news, and for soliciting and sharing
information on the latest developments in dioxin science
(http://www.epa.gov/ncea/dioxin).

How To Submit Technical Input to the Docket (including via
www.regulations.gov)

    Submit your input, identified by Docket ID No. EPA-HQ-ORD 2008-
0789, by one of the following methods:
    • On-line: www.regulations.gov. Follow the on-line
instructions for submitting input.
    • E-mail: ORD.Docket@epa.gov.
    • Fax: 202-566-1753.
    • Mail: Office of Environmental Information (OEI) Docket
(Mail Code: 2822T), U.S. Environmental Protection Agency, 1200
Pennsylvania Ave., NW., Washington, DC 20460. The phone number is 202-
566-1752.
    • Hand Delivery: The OEI Docket is located in the EPA
Headquarters Docket Center, Room 3334 EPA West Building, 1301
Constitution Ave., NW., Washington, DC. The EPA Docket Center Public
Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through
Friday, excluding legal holidays. The telephone number for the Public
Reading Room is 202-566-1744. Such deliveries are only accepted during
the docket's normal hours of operation, and special arrangements should
be made for deliveries of boxed information. If you provide information
by mail or hand delivery, please submit three copies.
    Instructions: Direct your input to Docket ID No. EPA-HQ-ORD-2008-
0789. Please ensure that your information is submitted within the
specified open period. Information received after the closing date will
be marked ``late,'' and may only be considered if time permits. It is
EPA's policy to include all information it receives in the public
docket without change and to make this information available online at
www.regulations.gov, including any personal information provided,
unless the submission includes information claimed to be Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Do not submit information that you consider to
be CBI or otherwise protected through www.regulations.gov or e-mail.
The www.regulations.gov Web site is an ``anonymous access'' system,
which means EPA will not know your identity or contact information
unless you provide it in the body of your information. If you send an
e-mail directly to EPA without going through www.regulations.gov, your
e-mail address will be automatically captured and included as part of
the input that is placed in the public docket and made available on the
Internet.

     Dated: November 11, 2008.
Peter W. Preuss,
Director, National Center for Environmental Assessment.
[FR Doc. E8-27853 Filed 11-21-08; 8:45 am]
BILLING CODE 6560-50-P

 
 


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