National Water-Quality Assessment (NAWQA) Project
The combined results from the local, regional, and national monitoring studies indicate that a wide variety of pesticides are present in the atmosphere. Nearly every pesticide that has been investigated has been detected in air, rain, snow or fog throughout the country at different times of the year. And, there is ample evidence that some long-lived pesticides used in one area of the country migrate through the atmosphere and are deposited in other areas of the country, sometimes in areas where pesticides are not used. The atmosphere is an important part of the hydrologic cycle that can transport pesticides from their point of application and deposit them in unintended areas. Average annual concentrations of pesticides in air and rain are generally very low, although elevated concentrations may occur during periods of high use, usually in the spring and summer months. The environmental effects of long-term occurrences of low levels of pesticides in the atmosphere are not yet well understood.
U.S. Environmental Protection Agency, 1994, Deposition of air pollutants to the Great Waters, first report to congress: EPA 453/R-93-055, 89 p.
Goolsby, D.A., Thurman, E.M., Pommes, M.L., and Battaglin, W.A., 1994, Temporal and Geographic Distribution of Herbicides in Precipitation in the Midwest and Northeast United States, 1990-91: in Weigmann, D.L., ed., New directions in pesticide research, development, management, and policy, Proceedings or the Fourth National Pesticide Conference, Richmond, Viginia, Nov. 1-3, 1993.
Chief, Pesticide National Synthesis
U.S. Geological Survey
6000 J Street
Sacramento, CA 95819-6129
Additional information on NAWQA and other U.S. Geological Survey programs can be found by accessing the NAWQA "home page" on the World Wide Web at: " http://water.usgs.gov/nawqa/."
U.S. Geological Survey, Fact Sheet FS-152-95