E6-6755. Considerations for Developing Alternative Health Risk Assessment Approaches for Addressing Multiple Chemicals, Exposures and Effects; External Review Draft

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of peer-review workshop.

SUMMARY:

EPA is announcing that Eastern Research Group, Inc., an EPA contractor for external scientific peer review, plans to convene an independent panel of experts and organize and conduct an external peer-review workshop to review the external review draft document titled, “Considerations for Developing Alternative Health Risk Assessment Approaches for Addressing Multiple Chemicals, Exposures and Effects; External Review Draft” (EPA/600/R-06/013A). The draft document was prepared by the National Center for Environmental Assessment (NCEA) within EPA's Office of Research and Development.

The external peer-review workshop provides an opportunity for all interested parties to comment on the document. EPA is releasing this draft document solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. This document has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency policy or determination.

Eastern Research Group, Inc. invites the public to register to attend this workshop as observers. In addition, Eastern Research Group, Inc. invites the public to give oral and/or provide written comments at the workshop regarding the draft document under review. The draft document and EPA's peer-review charge are available primarily via the Internet on NCEA's home page under the Recent Additions and the Data and Publications menus at http://www.epa.gov/​ncea. On March 31, 2006, EPA announced a 45-day public comment period on the draft document (71 FR 16306). In preparing a final report, EPA will consider public comments it received during the public comment period and will consider the Eastern Research Group, Inc. report of the comments and recommendations from the external peer-review workshop.

DATES:

The peer-review panel workshop will begin on May 25, 2006, at 9 a.m., adjourning at 5:30 p.m. and will continue on May 26, 2006 at 9 a.m., adjourning at 3 p.m.

ADDRESSES:

The peer-review workshop will be held at the Andrew W. Briedenbach Environmental Research Building, 26 W. Martin Luther King Dr., Cincinnati, OH, 45268, in room AG-30. The EPA contractor, Eastern Research Group, Inc., is organizing, convening, and conducting the peer-review workshop. Observers may attend the meeting of the expert panel by filling out the form available on the Internet at https://www2.ergweb.com/​projects/​conferences/​ncea/​ or by calling Eastern Research Group, Inc.'s conference line between the hours of 9 a.m. and 5:30 p.m. EST at 781-674-7374 or toll free at 800-803-2833, or by faxing a registration request to 781-674-2906 (include full address and contact information). Pre-registration is strongly recommended as space is limited, and registrations will be accepted on a first-come, first-served basis. The deadline for online pre-registration is May 18, 2006. Telephone and fax registrations will continue to be accepted after this date, including on-site registration, if space allows.

The draft “Considerations for Developing Alternative Health Risk Assessment Approaches for Addressing Multiple Chemicals, Exposures and Effects; External Review Draft” (EPA/600/R-06/013A) is available primarily via the Internet on the National Center for Environmental Assessment's home page under the Recent Additions and the Data and Publications menus at http://www.epa.gov/​ncea.

A limited number of paper copies are available from Ms. Donna Tucker, Technical Information Manager, NCEA-Cincinnati; telephone: [phone]; facsimile: 513-569-7916; e-mail: [e-mail]. If you are requesting a paper copy, please provide your name, your mailing address, and the document title, “Considerations for Developing Alternative Health Risk Assessment Approaches for Addressing Multiple Chemicals, Exposures and Effects,” and its EPA publication number, EPA/600/R-06/013A.

Copies are not available from Eastern Research Group, Inc.

FOR FURTHER INFORMATION CONTACT:

Questions regarding information, registration, and logistics for the external peer-review workshop should be directed to Eastern Research Group, Inc. at 10 Hartwell Avenue, Lexington, MA 02421-3136; by telephone: [phone] or toll free at 800-803-2833; or by facsimile: 781-674-2906; or by e-mail: [e-mail].

For technical information, contact Linda K. Teuschler, NCEA-Cincinnati, by telephone: [phone]; facsimile: 513-487-2539; or e-mail: [e-mail].

SUPPLEMENTARY INFORMATION:

I. Summary of Information About the Project/Document

In EPA's 2003 “Framework for Cumulative Risk Assessment,” cumulative risk assessment is defined as the evaluation of risks from exposures to multiple chemicals and other stressors, and having a population focus rather than a source-to-receptor focus. Several reports and environmental justice concerns published over the past 11 years have highlighted the importance of estimating cumulative risks. EPA has published several guidance documents dealing with specific aspects of cumulative risk, such as chemical mixture risk assessment, planning and scoping, stakeholder involvement, and the toxicity from a mixture of pesticides sharing a common mode of action. This draft document is one contribution to EPA's efforts to address issues related to cumulative health risk assessment.

Existing EPA guidance addresses some of the combination aspects of cumulative risk, but none addresses all of the multiples included in this report, such as consideration of the composite impact of multiple health effects. Among the distinctive new approaches are those for grouping chemicals based on exposure characteristics and toxic endpoints, multi-route combination of relative potency factors, integration of categorical regression modeling of multiple effects with additivity approaches, and the emphasis on the iteration and collaboration between exposure assessment and dose-response assessment to ensure compatible and relevant information. Major findings and conclusions in this document are as follows:

• This draft report provides a set of approaches that deal with certain complications in cumulative risk assessment, specifically those caused by multiple chemicals, exposures and effects, including toxicological interactions and environmental transformations of mixture component chemicals.
• The scope is focused on the evaluation of health risks from exposures to multiple chemicals, including multiple exposure routes and times as well as multiple health endpoints.
• Areas of cumulative health risk assessment emphasized in this report can often be performed with existing information.
• Exposure and toxicity characterizations of mixtures are strongly dependent on mixture composition (chemicals and concentrations) and timing of exposures and health effects.
• Qualitative and semiquantitative approaches provided can simplify the number of potential combinations of chemicals, exposures, and effects to make the cumulative health risk assessment more feasible.

II. Workshop Information

Members of the public may attend the workshop as observers, and there will be a limited time for comments from the public in the afternoon. Please let Eastern Research Group, Inc. know if you wish to make comments during the workshop. (See ADDRESSES section above for contact information.) Space is limited, and reservations will be accepted on a first-come, first-served basis.

Dated: May 1, 2006.

P.W. Preuss,

Director, National Center for Environmental Assessment.