The EPA is re-evaluating the safety of atrazine, one of the most widely used pesticides in the United States, and indeed the world. Several groups in the science and farming communities have called for its review  over mounting evidence of its environmental and human health hazards, despite the whitewash it received under the Bush administration. The defenders of atrazine claim that it is indispensable in growing corn in the Midwest; I’ve written about the economics of an atrazine ban here.

In the debate surrounding atrazine — Syngenta, the manufacturer, insists it is safe, despite more and more research to the contrary — a new controversy has appeared.

Syngenta has accused a leading atrazine researcher, UC Berkeley integrative biology professor Tyrone Hayes, of sending obscene and harassing emails to its staff. Hayes says he was responding to personal threats from individual staff members at Syngenta, and asserts his right to communicate in an often rhyming, rap-style voice as part of his culture.

The most important thing about this controversy is what it’s not about. If Syngenta had solid proof that Hayes’ research on atrazine was flawed, it wouldn’t need to talk about his emails. Hayes is well-known for proving, repeatedly, that atrazine is a powerful endocrine disruptor; even minute doses can turn male frogs into hermaphrodites. And, he says, frogs have the same reproductive hormones as humans: atrazine, at incredibly low concentrations, catalyzes the conversion of testosterone into estrogen in male frogs.