Atrazine (Herbicide in Water)

Atrazine is the second-most used herbicide in the US (80 million pounds per year on corn crops), and it routinely contaminates drinking water in agricultural areas. It's banned in the EU since 2004 due to groundwater contamination concerns. UC Berkeley researcher Tyrone Hayes published studies showing atrazine causes hormonal disruption and sex changes in frogs at concentrations below EPA limits. Syngenta (the manufacturer) spent years attacking Hayes's reputation (revealed in court documents). The EPA has repeatedly reviewed and re-approved atrazine. EU and US regulators look at the same data and reach opposite conclusions.