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Environmental Health - Toxic Substances

Crosscutting Topics

Agricultural Chemicals

Occurrence and fate of chemicals used for agriculture

One focus of the USGS Toxic Substances Hydrology (Toxics) Program is to investigate the occurrence and fate of agricultural chemicals in the environment from pesticides, fertilizers, veterinary medicines, and other sources. A wide variety of Toxics Program investigations study the fate of agricultural chemicals either directly or indirectly. Toxics Program agricultural chemical investigations focus on:

  • Characterizing the processes that affect the dispersal of chemicals in the atmosphere, ground water, and surface water
  • Discovering the processes that control the fate of nutrients in the environment
  • Identifying persistent pesticide degradation products
  • Developing methods to measure these compounds in water samples at environmentally relevant concentrations
  • Assessing the impact of hypoxia, eutrophication, and other processes on water bodies receiving drainage from agriculturally dominated watersheds

Results of these investigations are used by government regulators, pesticide manufacturers, farmers, water resource managers, and the public to set sound policy on the use of agricultural chemicals. The information presented on this page cuts across lines drawn by individual investigations and projects so that the information on the fate of agricultural chemicals can be presented in one place.

Investigations and Research Activities

Fact Sheets

USGS technicians collecting water samples from a bridge
USGS technicians collecting water samples from a bridge for a reconnaissance of herbicide concentrations in streams
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A small tractor with a tiller attachment on an test plot.
Incorporating encapsulated herbicide (Atrazine) into the soil as part of an experiment to determine if encapsulating herbicides reduces runoff. The white pipes sticking up out of the ground are lysimeters used to sample water from the unsaturated zone.
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Headlines

An autosampler set up to collect water samples from Black Creek near Blitchton, GA
An autosampler set up to collect water samples for analysis of pesticides during storm events as part of a reconnaissance of stream waters in peanut production areas in the southeastern United States. The autosampler was located on Black Creek near Blitchton, Georgia (circa 2003).
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Bibliography

Publications on Agricultural Chemicals (714 Publications)

New Publications

USGS scientist collecting a large-volume water samples from the San Joaquin River near Vernalis, CA
The analysis of pesticides sometimes requires large-volume water samples to detect pesticides that are toxic at low concentrations. This is a view of a pump used to collect samples from the San Joaquin River near Vernalis, CA (circa 2000). The sampling effort was part of a project to study pesticides and other anthropogenic chemicals in the San Francisco Bay/Delta
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Diagram of an Atrazine molecule showing replacement of its chlorine atom with a hydroxyl group.
Diagram of an Atrazine molecule showing replacement of its chlorine atom with a hydroxyl group. Hydroxyatrazine is a metabolite of Atrazine commonly found in ground water. Atrazine is a herbicide used on corn and sorghum. Atrazine and other herbicides were studied as part of a reconnaissance of herbicide concentrations in streams
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Page Last Modified: Thursday, 24-Jul-2014 15:39:05 EDT