Toxic Substances Hydrology Program
Where are the Pesticides?
The U.S. Geological Survey (USGS), the U.S. Environmental Protection Agency, the Iowa Department of Natural Resources, and the University of Iowa Hygienic Laboratory have been studying the occurrence and distribution of herbicides and their degradates in Iowa's ground water. Iowa is in the heart of the Corn Belt, a multi-state area that has the most productive farmland in the world. The agricultural productivity of this area goes hand in hand with the extensive use of herbicides to control weeds. Past studies on herbicides in ground water have only studied herbicide parent compounds and found minimal concentrations of herbicides. The study has shown that
The results of this study and other Toxics Program studies have prompted the USGS's National Water-Quality Assessment (NAWQA) Program to double the number of degradates in its national assessment on the occurrence of pesticides. In addition, the State of Iowa is now including pesticide degradates in the State's plan for water-quality monitoring.
More Information on Pesticides
Kolpin, D.W., Thurman, E.M., and Linhart, S.M., 1999, Finding minimal herbicide concentrations in ground water? Try looking for the degradates, in Morganwalp, D.W., and Buxton, H.T., eds., U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, 1999--Volume 2 of 3--Contamination of Hydrologic Systems and Related Ecosystems: U.S. Geological Survey Water-Resources Investigations Report 99-4018B, p. 247-254.
Kolpin, D.W., Thurman, E.M., and Linhart, S.M., 1998, The environmental occurrence of herbicides--The importance of degradates in ground water: Archives of Environmental Contamination and Toxicology, v. 35, n. 3, p. 385-390.