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A REGIONAL APPROACH TO ECOLOGICAL RISK ASSESSMENTS FOR PRODUCT REGISTRATION
Citation:
Pfleeger, T G. A REGIONAL APPROACH TO ECOLOGICAL RISK ASSESSMENTS FOR PRODUCT REGISTRATION. Presented at OPPTS meeting, Washington, DC, June 26, 2002.
Description:
Currently, most ecological risk assessments for EPA registration are evaluated at the national scale using a predetermined list of species with little regard to where the product will ultimately be used. The assumption is that the test species presently used are representative and therefore protective of all species within the United States and in many cases other parts of the world. This assumption has been questioned for over ten years by EPA personnel and others. EPA scientist at the Corvallis, OR laboratory are now in the process of developing a research program to test this assumption using the Nontarget Plant Test Guidelines (OPPTS 850.4225 and 8504250) as a model system. A GIS (geographical information system) approach is being used to determine areas within the United States which are at the highest risk from off target movement of herbicides. Areas are considered to be at high risk are those that have 1) high percentage of land treated with herbicides, 2) high herbicide application rates lb/acre, 3) diversified agriculture, and 4) mean wind speeds of 10 mph or greater during the growing season. A prototype of this methodology has been developed on the US corn belt at the county level. Counties determined to be at highest risk based on these criteria were further investigated to determine acreage of other crops, the dominant native plant species, important plant species for wildlife and rare/endangered plant species. This will result in a list of plant species of ecological and economic importance that are at risk from the off target movement of herbicides used in the corn belt region. These species will then be grown in the greenhouse to develop suitable culture practices and examine their sensitivity to a range of herbicide classes. This research is designed to provide more accurate test protocols by giving careful consideration to the differences in ecological and agricultural conditions that prevail in different regions of the US.