Based on the recommendation of a Science Advisory Panel (SAP), and under EPA guidance, two large-scale studies were conducted in separate laboratories using 3,200 frogs and 100,000 tissue samples to determine whether atrazine has an impact on growth, development, survival or sexual differentiation in frogs. The EPA audited and inspected the data from these studies and found that, “The data are sufficiently robust to outweigh previous efforts to study the potential effects of atrazine on amphibian gonadal development" and "there is no compelling reason to pursue additional testing.” In a different study, Yale University researchers surveyed frog populations in forests, agricultural areas, suburbs and cities in the U.S. Northeast and found that frogs were thriving in rural ponds near agricultural areas, rather than those in suburbs and cities who had significantly more deformities.
Atrazine is registered in many countries around the world, including the U.S., Australia and Canada, with each country evaluating environmental fate and effects. In the U.S., EPA, the U.S. Fish and Wildlife Service and the National Marine Fisheries Service are undertaking a national Endangered Species Assessment to analyze the potential effects of atrazine exposure on endangered species. Syngenta continues to actively research and support the environmental safety of atrazine.