During [a] trip to Africa, Hayes noticed that one species of frogs characterized by a distinct difference in color between male and female was actually changing to where some of the male frogs were taking on the spotted yellow colors of their female counterparts instead of the male green color.

Hayes had a theory the male frogs were changing because of the contaminates in the water. He theorized that water contained high concentrations of the female hormone estrogen.

When he got back to the states, he tested his theory by giving frogs different types of estrogen, which proved different forms of the hormones were causing the physical changes in the frogs.

After word got out that Hayes’s frogs could tell if substances had a harmful amount of concentration of estrogen, Hayes was hired by Syngenta Corporation to test their herbicide Atrazine.

“Here’s what I found: Atrazine inhibited the growth of the voice box in males,” Hayes said. “Now that’s bad news for the company because the same reason why males have lower voices, testosterone, is the some things that males frogs have that females don’t. This data implied that Atrazine demasculinized the male frogs. I like to use the term ‘chemically castrating’ because it pisses them off.”

He knew that Atrazine was harmful to amphibians, and he knew that amphibian hormones were sometimes almost identical to mammals, so what were Atrazine’s effects on mammals, including humans?

After even more tests and experiments he and his undergraduates at the University of California-Berkely stumbled across a startling discovery. Mammals- lab rodents- that were exposed to Atrazine induced breast and prostate cancer and were also more likely to have abortions.

If Atrazine had these deadly affects on lab rats, what were the effects on humans who were drinking water that was contaminated with Atrazine? What about the farmers and fieldworkers that were constantly being exposed to concentrations of Atrazine over long periods of time?