AGRO 145 |
| Empirical regression models were developed to predict organochlorine pesticide concentrations in whole fish from unmonitored U.S. streams on the basis of fish lipid content and watershed characteristics. Models were developed for DDT compounds, chlordane compounds, and dieldrin using whole-fish data collected from 650 streams nationwide by the U.S. Geological Survey's National Water Quality Assessment (NAWQA) Program. The most important explanatory variables were fish lipid content and various watershed characteristics, including past agricultural-pesticide use intensity, surrogate variables representing past termiticide use, population density, and forested land where past pesticide use was likely minimal. Variables representing fish taxa or geographic regions were of secondary importance. These models typically explained 50-70 percent of the variability in pesticide concentrations measured in whole fish. Only one model (p,p'-DDT) was improved substantially when the measured pesticide concentration in bed sediment from the same streams was included as an explanatory variable. |
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Estimation of Environmental Exposure to Agrochemicals Using Spatial Data Analysis and Geographic Information Systems
8:30 AM-12:10 PM, Wednesday, March 28, 2007 McCormick Place South -- Room S103B/C, Level 1, Oral
Division of Agrochemicals |