Atrazine and amphibians: Data re-analysis and a summary of the controversy

Abstract

The herbicide atrazine is one of the most commonly used, well studied, and controversial pesticides on the planet. Much of the controversy involves the effects of atrazine on wildlife, particularly amphibians and their non-infectious and infectious diseases, including diseases caused by trematode infections. Here I re-analyze data from authors that were funded by Syngenta Crop Protection, Inc., the company that produces atrazine, and show that even these authors revealed that increasing concentrations of atrazine applied to outdoor mesocosms increases the population growth rate of snails that can transmit trematode parasites to amphibians. These researchers missed this finding in their data because they never calculated population growth rates for the snail populations before they reached a carrying capacity or crashed. These results demonstrate that both Syngenta-funded and non-Syngenta-funded researchers have provided evidence that ecologically relevant concentrations of atrazine are capable of increasing snail populations. Given the controversy surrounding the effects of atrazine on amphibians, I follow this re-analysis with a timeline of some of the most salient events in the history of the atrazine-amphibian controversy.