ABSTRACT
This chapter shows that pesticides have been detected in every region of the United States where surface waters have been analyzed. In order to examine general patterns of occurrence of pesticides in surface waters, results from the state and local studies are combined with data from national and multistate studies. The best existing data to assess the occurrence and distribution of pesticides in surface waters, and the relation to pesticide use on a broad scale, are the national and multistate studies. A cooperative study conducted by the United States Geological Survey and the United States Environmental Protection Agency examined pesticides in water and bed sediments of rivers throughout the United States between 1975 and 1980. Herbicide use has increased substantially since the 1960’s and accounts for approximately 75% of the total agricultural use of pesticides. Fungicides, representing approximately 10% of all pesticide use, have significantly different use patterns than the herbicides and insecticides.
