In 2007, the EPA concluded that "atrazine does not adversely affect amphibian gonadal development based on a review of laboratory and field studies…" The Agency reiterated this position in April 2010, saying that "...no additional testing is warranted to address this issue."
In addition, a survey of frog populations in forests, agricultural areas, suburbs, and cities in the U.S. Northeast and found that frogs were thriving in rural, agricultural communities, while frogs in cities and suburbs had much higher deformity rates. A similar survey of the native northern leopard frog shows that it continues to thrive in areas where atrazine is heavily used, including in irrigation ditches next to cornfields in the U.S. Midwest.