U.S. Geological Survey Pesticides in Surface Waters Current Understanding of Distribution and Major Influences u G

This report summarizes a comprehensive analysis of existing information on national and regional patterns of pesticide occurrence in surface waters of the United States and the major influences on the sources and transport of pesticides. It is one of a four-part series that synthesizes current knowledge and understanding of pesticides in the nation's water resources as part of the National Water Quality Assessment Program. Pesticides in the Hydrologic System More than 1.1 billion pounds of pesticides are used each year in the United States. National agricultural use of herbicides, insecticides, and fungicides has grown from 190 million pounds of active ingredient in 1964 to an estimated 811 million pounds in 1993. Although the use of pesticides has resulted in increased crop production and other benefits, concerns about the potential adverse effects of pesticides on environmental and human health have grow