What additional complexities should be considered in the assessment of potential effects on aquatic life and fish-eating wildlife?
Pesticides may have substantially greater effects on aquatic ecosystems than on humans based on comparisons of USGS findings to water-quality benchmarks for aquatic life and fish-eating wildlife. More than 80 percent of urban streams and more than 50 percent of agricultural streams had concentrations in water of at least one pesticide—mostly those in use during the study period—that exceeded a water-quality benchmark for aquatic life. Urban streams had the highest proportion of benchmark exceedances in water (more than 80 percent of sites)—mostly by the insecticides diazinon, chlorpyrifos, and malathion—although frequencies of exceedance declined during the study period. Specifically, concentrations exceeded benchmarks in 95 percent of urban streams sampled during 1993-97 and in 64 percent of streams during 1998-2000. Most urban uses of diazinon and chlorpyrifos have been phased out since 2001 because of use restrictions impose by EPA. More than 50 percent of the agricultural streams h
Related Questions
- Why do pesticides exceed water-quality benchmarks for aquatic life and fish-eating wildlife more often in urban areas than in agricultural areas?
- What additional complexities should be considered in the assessment of potential effects on aquatic life and fish-eating wildlife?
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