"The Environmental Protection Agency plans to conduct a new study about the potential health risks of atrazine, a widely used weedkiller that recent research suggests may be more dangerous to humans than previously thought.

Atrazine -- a herbicide often used on corn fields, golf courses and even lawns -- has become one of the most common contaminants in American drinking water.

For years, the E.P.A. has decided against acting on calls to ban the chemical from environmental activists and some scientists who argued that runoff was polluting ecosystems and harming animals.

More recently, new studies have suggested that atrazine in drinking water is associated with birth defects, low birth weights and reproductive problems among humans, even at concentrations that meet current federal standards."

Charles Duhigg reports for the New York Times October 7, 2009. [2]