Atrazine is a synthetic chemical commonly used to kill weeds in the production of such crops as corn, sorghum, and sugar cane. It ranks as one of the most widely used herbicides (weed-killing chemicals) in the world. Because it is effective, easy to apply, and relatively inexpensive, people have used atrazine for many years over wide geographical areas. However, the chemical has been known to contaminate both surface water and ground water (water held beneath the ground), causing some experts to fear its widespread use may harm people and wildlife. In the United States, only certified professionals can purchase and use atrazine. The European Union has banned the use of atrazine.
Atrazine works by interfering with photosynthesis, a process that green plants use to convert sunlight into energy. The targeted crop can detoxify atrazine—making it harmless—but certain broadleaf and grass weeds cannot. Thus, applying atrazine to a crop field kills harmful weeds but does not damage the crop.
Atrazine can remain stable in water, and runoff from croplands where the chemical is applied can contaminate water sources. Contamination can be reduced by avoiding the use of atrazine near water sources, such as lakes, reservoirs, rivers, or wells.