Atrazine is an agricultural pesticide. It is most heavily used in the Midwest on corn, surgarcane and sorghum crops. While atrazine is an effective herbicide used for weed management, it is also being evaluated regularly be the Environmental Protection Agency (EPA) for its potential impacts on the environment and human health.
In the late 1980s, atrazine was one of the most popular pesticides used in the U.S. Farmers, particularly in the Midwest, have relied on atrazine to manage broadleaf and grassy weeds in crops. Atrazine is now a restricted-use pesticide because of its potential to leach into groundwater. Concerns regarding the presence of atrazine in drinking water and the potential impacts on animals and human health have risen in recent years. In 2009 the EPA opened a new risk assessment plan to review the latest science on atrazine.
Atrazine is applied to crops by spraying. It settles into the soil and begins to break down. Once in the soil, atrazine can leach into groundwater, ponds, rivers and irrigation canals. Both animals and humans are then at risk of exposure. The EPA has set Maximum Containment Level Goals (MCLs) for atrazine based on the possible health risks from exposure, but these levels are nonenforceable. As of 2010 the MCLs for atrazine were under review by the EPA to be sure recommended safe exposure levels, particularly in water, are accurate, based on emerging science.
The health impacts of short-term exposure to atrazine above the recommended safe exposure levels include low blood pressure; congestion of the heart, lungs and kidneys; damage to adrenal glands (a part of the endocrine system responsible for releasing stress hormones); weight loss; and muscle spasms. It is also a mild skin irritant, which can result in rashes. People who have been exposed to higher-than-recommended levels of atrazine over time may experience cardiovascular damage, muscle degeneration and weight loss. The EPA is evaluating the science linking atrazine to cancer and disruptions in the endocrine system of both animals and humans.
Farm workers, workers in factories where the pesticide is manufactured and those who live and work close to atrazine-contaminated water are at the most risk for exposure. The EPA requires all water suppliers to test for atrazine every three months. The best way to reduce exposure is to stay away from fields where spraying has occurred, test well water for contamination and contact your local water manager for updated water testing data.
Some scientists, such as Dr. Tyrone Hayes at U.C. Berkeley, believe the potential health impacts of atrazine exposure are more harmful than currently stated. Hayes' research shows atrazine has a significant impact on the reproductive health of amphibians, perhaps reducing fertility in frogs to as low as 10 percent. What is known is that exposure to atrazine should be limited when possible and that those who use the pesticide should follow all recommended precautions to prevent excessive exposure.