Analysis of Laboratory and Field Studies of Reproductive Toxicity in Birds Exposed to Dioxin-Like Compounds for Use in Ecological Risk Assessment

AGENCY:

Environmental Protection Agency.

ACTION:

Notice of availability.

SUMMARY:

This notice announces the availability of a final report titled, Analysis of Laboratory and Field Studies of Reproductive Toxicity in Birds Exposed to Dioxin-Like Compounds for Use in Ecological Risk Assessment (EPA/600/R-03/114F), which was prepared by the U.S. Environmental Protection Agency's (EPA) National Center for Environmental Assessment (NCEA) of the Office of Research and Development (ORD).

DATES:

This document will be available on or about January 7, 2004.

ADDRESSES:

The document will be made available electronically through the NCEA Web site ( http://www.epa.gov/ncea ). A limited number of paper copies will be available from the EPA's National Service Center for Environmental Publications (NSCEP), P.O. Box 42419, Cincinnati, OH 45242; telephone: 1-800-490-9198 or 513-489-8190; facsimile: 513-489-8695. Please provide your name, your mailing address, the title and the EPA number of the requested publication.

FOR FURTHER INFORMATION CONTACT:

The Technical Information Staff, National Center for Environmental Assessment/Cincinnati Office (MS-117), U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive, Cincinnati, OH 45268. Telephone: 513-569-7257; fax: 513-569-7475; e-mail: nceadc.comment@epa.gov.

SUPPLEMENTARY INFORMATION:

Coplanar PCBs and other dioxin-like chemicals are common environmental contaminants and risks to wildlife are a significant issue as demonstrated by observed reproductive effects on birds and other wildlife. However, a number of scientific and technical issues are involved in performing the needed assessments such as the proper treatment of mixtures, identification of the critical effects, and proper exposure metrics. This report explains the proper use of data for individual congeners and identifies developmental effects from in ovo exposures as the proper endpoint. It also deals with the problem of evaluating a large and heterogeneous literature by identifying a set of appropriate avian toxicity data. Another assessment issue is the lack of a standard or generally accepted method for modeling effects on wildlife or calculating screening benchmarks. This problem is exacerbated by the fact that wildlife test methods are not well standardized, except in pesticide registration. Hence, although there is a plethora of test data for dioxin-like chemicals and wildlife, relatively little of it was suitable for assessment. Finally, the chronic data were not as useful as they could have been, because test results in the literature were nearly always expressed as statistically significant concentrations rather than biological effects levels. The report presents alternative ways to deal with these issues.