2010-12280. Draft EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of Public Comment Period.

SUMMARY:

EPA is announcing a 90-day public comment period for the external review draft entitled, “EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments” (EPA/600/R-10/038A). This draft report responds to the key recommendations and comments included in the National Academy of Sciences (NAS) 2006 report. In addition, it includes new analyses on potential human effects that may result from exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). These analyses have not been in previous versions of draft reports related to EPA's dioxin reassessment activity. This draft report is now considered to be under EPA's Integrated Risk Information System (IRIS) program, and thus, the new IRIS process announced in May 2009 (http://www.epa.gov/​iris/​process/​) is being followed. Per the May 2009 process, this draft report is beginning Step 4—independent external peer review and public review and comment. This draft dioxin report was prepared by the National Center for Environmental Assessment (NCEA) within the EPA Office of Research and Development (ORD).

The draft document, “EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments,” is also being provided to EPA's Science Advisory Board (SAB), a body established under the Federal Advisory Committee Act, for independent external peer review. The SAB will convene an expert panel composed of scientists knowledgeable about technical issues related to dioxins and risk assessment. The SAB is expected to hold a public teleconference on or about June 24, 2010, and a public panel meeting on July 13-15, 2010. The SAB peer review meetings will be announced by the SAB staff office in a separate Federal Register Notice. EPA intends to forward all public comments submitted before July 7, 2010, in response to this notice to the SAB peer review panel for their consideration. Members of the public who wish to ensure that their technical comments are provided to the SAB expert panel before each meeting should also e-mail their comments separately to Thomas Armitage, the SAB Designated Federal Officer at [e-mail], following the procedures in the Federal Register Notice announcing the SAB public meetings. When completing this draft dioxin report, EPA will consider any written public comments that EPA receives in accordance with the detailed instructions provided below under SUPPLEMENTARY INFORMATION. The public comment period and SAB external peer review are independent processes that provide separate opportunities for all interested parties to comment on the draft report.

EPA is releasing this draft report solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. This draft report has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency policy or determination.

DATES:

The public comment period begins May 21, 2010, and ends August 19, 2010. Comments should be in writing and must be received by EPA by August 19, 2010.

Due to the timing of the SAB's peer review meeting, EPA can only guarantee that those comments received by July 7, 2010, in response to this Federal Register notice will be provided to the SAB panel prior to the SAB meeting. Comments received after July 7, will still be provided to the SAB panel and will also inform the Agency's revision of the draft report.

ADDRESSES:

The external review draft titled, “EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments” (EPA/600/R-10/038A) is available primarily via the Internet on the NCEA home page under the Recent Additions and Publications menus at http://www.epa.gov/​ncea. A limited number of paper copies are available from the Information Management Team (Address: Information Management Team, National Center for Environmental Assessment (Mail Code: 8601P), U.S. Environmental Protection Agency, 1200 Pennsylvania Avenue, NW., Washington, DC 20460; telephone: [phone]; facsimile: 703-347-8691). If you request a paper copy, please provide your name, mailing address, and the assessment title.

Comments may be submitted electronically via http://www.regulations.gov,, by e-mail, by mail, by facsimile, or by hand delivery/courier. Please follow the detailed instructions provided in the SUPPLEMENTARY INFORMATION section of this notice.

FOR FURTHER INFORMATION CONTACT:

For information on the docket, regulations.gov or public comment period, please contact the Office of Environmental Information (OEI) Docket (Mail Code: 2822T), U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460; telephone: [phone]; facsimile: 202-566-1753; or e-mail: [e-mail].

For information on the draft report, please contact Linda C. Tuxen, National Center for Environmental Assessment (8601P), U.S. Environmental Protection Agency, 1200 Pennsylvania Avenue, NW., Washington, DC 20460; telephone: [phone]; facsimile: 703-347-8699; or e-mail: [e-mail].

SUPPLEMENTARY INFORMATION:

I. Information About the Draft Report, “EPA's Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments”

In 2003, EPA, along with other federal agencies, asked the NAS to review aspects of the science in EPA's draft dioxin reassessment entitled, “Exposure and Human Health Reassessment of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) and Related Compounds,” and, in 2004, EPA sent a 2003 external review draft dioxin reassessment to the NAS for their peer review. The NAS held several public meetings during their review of the draft reassessment and on July 11, 2006, released the final report of their review entitled, “Health Risks from Dioxin and Related Compounds: Evaluation of the EPA Reassessment.”

The NAS identified three key areas in the 2003 draft reassessment that required substantial improvement to support a more 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.

EPA's draft dioxin report, which is being provided for public review and comment, includes significant new analyses on both the potential cancer and noncancer human health effects that may result from exposures to TCDD. For instance, this draft report addresses the explicit recommendation of the NAS to develop a quantitative risk estimate for noncancer effects that may result from long-term (chronic) oral exposure to dioxins. Thus, this draft dioxin report includes an oral reference dose (RfD) for TCDD—the most well-studied and considered to be among the most toxic of the dioxin-like compounds. An RfD was not in the 2003 draft dioxin reassessment.

In addition, in 2003, EPA and other federal agencies developed a set of questions and answers related to dioxins, which have been updated about every year and a half. These materials have again been updated to include more recent information. These questions and answers provide general information on dioxins such as what they are, where they can be found, and major sources of dioxins. They also discuss possible effects of dioxin exposure in humans, include advice about consumption of food that might contain dioxins, and explain the review process for the dioxin reassessment. For additional information on dioxins and on EPA's overall dioxin assessment activity, these questions and answers may be accessed at: http://www.fda.gov/​Food/​FoodSafety/​FoodContaminantsAdulteration/​ChemicalContaminants/​DioxinsPCBs/​ucm077524.htm.

II. How To Submit Comments to the Docket at http://www.regulations.gov

Submit your comments, identified by Docket ID No. EPA-HQ-ORD-2010-0395, by one of the following methods:

• http://www.regulations.gov: Follow the on-line instructions for submitting comments.
• E-mail: [e-mail].
• Facsimile: 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 telephone number is 202-566-1752. If you provide comments by mail, please submit one unbound original with pages numbered consecutively, and three copies of the comments. For attachments, provide an index, number pages consecutively with the comments, and submit an unbound original and three copies.
• Hand Delivery: The OEI Docket is located in the EPA Headquarters Docket Center, EPA West Building, Room 3334, 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. 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 comments by hand delivery, please submit one unbound original with pages numbered consecutively, and three copies of the comments. For attachments, provide an index, number pages consecutively with the comments, and submit an unbound original and three copies.

Instructions: Direct your comments to Docket ID No. EPA-HQ-ORD-2010-0395. Please ensure that your comments are submitted within the specified comment period. Comments 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 comments it receives in the public docket without change and to make the comments available online at http://www.regulations.gov,, including any personal information provided, unless comments include 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 http://www.regulations.gov or e-mail. The http://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 comments. If you send e-mail comments directly to EPA without going through http://www.regulations.gov,, your e-mail address will be automatically captured and included as part of the comments that are placed in the public docket and made available on the Internet. If you submit electronic comments, EPA recommends that you include your name and other contact information in the body of your comments and with any disk or CD-ROM you submit. If EPA cannot read your comments due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comments. Electronic files should avoid the use of special characters and any form of encryption and be free of any defects or viruses. For additional information about EPA's public docket, visit the EPA Docket Center homepage at http://www.epa.gov/​epahome/​dockets.htm.

Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy. Publicly available docket materials are available either electronically at http://www.regulations.gov or in hard copy at the OEI Docket in the EPA Headquarters Docket Center.

Dated: May 17, 2010.

Rebecca Clark,

Acting Director, National Center for Environmental Assessment.