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United States Department of Agriculture

Agricultural Research Service


item Potter, Thomas
item Williams, Bill
item Kendall, Ronald
item Thrall, Mary Anna
item Adams, William
item Cobb, George
item Eslingler, Paul
item Hatfield, Kirk
item Lapointe, Thomas
item Moore, Dwayne

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/20/2000
Publication Date: 4/20/2000
Citation: Potter, T.L., Williams, B., Kendall, R., Thrall, M., Adams, W., Cobb, G., Eslingler, P., Hatfield, K., Lapointe, T., Moore, D. Report of FIFRA Scientific Advisory Panel Meeting, April 5-6, 2000. Implementation plan for probabilistic ecological risk assessment. U.S. EPA Office of Pesticide Programs, Washington, D.C. URL:

Interpretive Summary: Modern agriculture uses a variety of chemicals known collectively as pesticides to produce food and fiber economically and efficiently. Use of pesticides may present threats to public health and the environment. To minimize these threats, the Environmental Protection Agency (EPA) overseas the registration of all pesticides. This involves evaluating potential human and ecological risks from their use. The science of this process is termed Risk Assessment. Over the years, it has evolved from point-estimate to probabilistic approaches. The later include uncertainty analysis and allow a more informed assessment of potential risk. In 1997, EPA began a three-phase program for development and implementation of a tiered probabilistic ecological risk assessment methodology for use in pesticide registration programs. Phase 1 involved the formation of 48-member Ecological Committee on Federal Insecticide and Rodenticide Act (FIFRA) Risk Assessment Methods (ECOFRAM) which developed methods for predicting the magnitude and the probability of adverse effects of pesticide use on non-target organisms. In Phase 2, which is on-going, EPA used the ECOFRAM reports to develop an implementation plan. This plan was presented for peer-review to a Scientific Advisory Panel (SAP) in a public meeting held on April 5-6, 2000. This report contains the consensus response of the panel to EPA. Specific guidance was provided on pesticide environmental fate modeling, exposure and toxicity assessment, which will help the agency refine and improve its procedures.

Technical Abstract: The Probabilistic Risk Assessment Implementation Team of the USEPA Office of Pesticide Programs (EPA-OPP) submitted a draft implementation plan for peer-review to a FIFRA Scientific Advisory Panel (SAP) at a public meeting April 5-6, 2000. The agency's request for comment was put in the form of 25 questions to the panel. Panel members responded verbally and with this report. Overall, the SAP strongly endorsed EPA-OPP's commitment to tiered probabilistic risk assessment. However, the panel identified a number of limitations in the agency's implementation plan. It was noted that the current approach to assessing aquatic exposure at the highest tiers may not adequately predict environmental concentrations of pesticides at the water- shed scale. Regression-based models were recommended as an alternative to field-scale simulations using GEENEC and PRZM-EXAMS models. In commenting on aquatic toxicity assessments, the SAP identified a need for amphibian testing, additional sub-lethal tests, which evaluate endocrine disruption and other subtle toxic responses and approaches to reduce dependence on extrapolation factors when applying toxicity data across multiple levels of biological organization. In the assessment of the terrestrial pesticide exposure risks, the panel observed that the duration of exposure was a function of field dissipation rates, which may vary widely and that cumulative exposures may need to be considered. Additional modeling and field monitoring efforts were recommended in assessing exposure and toxic responses at the community level.

Last Modified: 10/17/2017
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