Atrazine has been showing up in the USA in supermarket corn, and in beef and milk. (Atrazine-treated corn is routinely fed to cattle.) And it has become one of the leading contaminants of drinking water. The chemical was found in 990 of 1,604 water samples drawn from streams, rivers, reservoirs and aquifers in the Midwest from 1989 to 1994. According to a 1997 estimate by the US Environmental Protection Agency, some corn farmers faced a 1 in 863 lifetime risk of developing cancer from atrazine. Non-farmers in the Midwest faced a 1 in 20,747 risk, and a 1 in 13,850 risk if they used atrazine on their lawns. The EPA generally takes regulatory action when a chemical poses a lifetime cancer risk higher than one in a million.
The US government has classified atrazine as a possible human carcinogen. Some studies conclude that it can damage DNA and induce gene mutations. Other studies have linked the chemical to hormonal changes.