A U.S. Geological Survey finds pesticides are typically present throughout the year in most streams in urban and agricultural areas.
The pesticides are less common in ground water and the report concludes that pesticides are seldom at concentration levels likely to affect humans.
However, in many U.S. streams, particularly those draining urban and agricultural areas, pesticides are found at concentrations that may affect aquatic life or fish-eating wildlife.
"While the use of pesticides has resulted in a wide range of benefits to control weeds, insects, and other pests, including increased food production and reduction of insect-borne disease, their use also raises questions about possible effects on the environment, including water quality," Robert Hirsch, associate director for water.
Copyright 2006 by United Press International
Explore further: Ceres bright spots sharpen but questions remain