The U.S. Geological Survey has released a report describing the occurrence of pesticides in streams and ground water during 1992-2001. The report concludes that pesticides are typically present throughout the year in most streams in urban and agricultural areas of the Nation, but are less common in ground water.
The USGS report is based on analysis of data collected from 51 major river basins and aquifer systems across the Nation from Florida to the Pacific Northwest and including Hawaii and Alaska, plus a regional study in the High Plains aquifer system.
The report also concludes that pesticides are seldom at concentrations likely to affect humans. However in many streams, particularly those draining urban and agricultural areas, pesticides were found at concentrations that may affect aquatic life or fish-eating wildlife.
The USGS findings show strong relations between the occurrence of pesticides and their use, and point out that some of the frequently detected pesticides, including the nsecticide diazinon and the herbicides alachlor and cyanazine, are declining.
