Why do pesticides exceed water-quality benchmarks for aquatic life and fish-eating wildlife more often in urban areas than in agricultural areas?
Exceedences in urban areas primarily relate to the more frequent presence of insecticides, which can be more toxic to aquatic life than herbicides. The pesticides with the greatest potential to affect urban streams during the study period were diazinon, chlorpyrifos, and malathion. The use of diazinon declined since the end of the 1992-2001 study period. Nonagricultural uses of chlorpyrifos have also been declining because of use restrictions (and the use of other pesticides may be changing as well). The reductions in use of some of the pesticides with the greatest potential for adverse effects (based on the USGS screening-level assessment) indicates that recent EPA restrictions on uses of diazinon and chlorpyrifos have the potential to reduce possible effects on aquatic life in urban streams if their uses are replaced with pesticides that reach streams in less toxic amounts or alternative approaches to pest control.
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?
- How Can WARP be Used to Assess the Potential for Effects of Pesticides on Humans or Aquatic Life?
