Atrazine fact-check

Recent articles from The New Yorker and on Democracy Now are calling some attention to the herbicide Atrazine and its possible effects on hormones. These articles concentrate on how the maker of Atrazine, Syngenta corporation, persecuted one of the main researchers into harmful effects of Atrazine.

There are some alarming quotes, such as "we found that not only were these males [frogs] demasculinized, or chemically castrated, but they also were starting to develop ovaries or starting to develop eggs. And eventually we discovered that these males didn’t breed properly, that some of the males actually completely turned into females." (quoted from the Democracy Now interview)

Conflicting claims come from sides in favor or against Atrazine. The company's PR site quotes a 2006 EPA assessment on the safety of Atrazine, which concluded that is posed "no harm that would result to the general U.S. population, infants, children or other major identifiable subgroups of consumers," and also that there were no effects on the reproduction of amphibians. On the other hand, various studies connect Atrazine not only with the above "hermaphroditism" in frogs, but also with menstrual irregularities in humans and birth defects and cancer.

Looking into the company's claims that the EPA agrees about the safety of Atrazine quickly reveals that there is an ongoing re-evaluation of the 2006 findings. From the EPA's own website we can find a report from a June 2012 meeting on the subject. This report criticizes the previous EPA study for throwing out all but one of 75 studies for technical reasons, leaving one study on an African species of frog which found no effects: "the results of this study are insufficient to make a global conclusion that atrazine has no effect on all amphibian species at concentrations less than 100 μg/L." The report expressed great concern about about effects at much lower concentrations: "The Panel examined all of the data from Figs. 7, 8, 9 in the White Paper and found that atrazine caused effects on metamorphosis, growth, and sexual development at 1 ppb and above."

Syngenta has settled a lawsuit over Atrazine in drinking water, paying money to affected communities to help them filter the herbicide out of their water. This New York Times article provides some good summary data on Atrazine levels. It mainly affects highly agricultural areas, particularly corn producing areas. Concentration levels in drinking water experience seasonal spikes far above the EPA's allowed yearly average value of 3 ppb, due to its seasonal use in agriculture.

 There is plenty here to be scared about.