Activist Scientists

Tyrone Hayes, Ph.D., a professor at the University of California-Berkeley, has conducted research that he claims shows atrazine harms frogs. What you might not know is that Hayes is well known to the scientists of the EPA, who reviewed four of his studies during the agency’s 2002 and 2003 examination of atrazine. They even visited Hayes’ lab, and reviewed some of his raw findings. According to Anne E. Lindsay, who was deputy director of the EPA’s Office of Pesticide Programs at the time, the agency found Hayes’ studies (and lots of others) are too flawed and inconsistent to be considered proof that atrazine harms frogs. Yet, in 2020, Hayes continues get speaking engagements touting his junk science. Here’s what one science columnist said in a Jan. 28, 2020 column on the website. 

Hayes participated in yet another study, released in 2010, also making claims about the amphibians. As with all such reviews, the EPA will no doubt take this work into consideration as they conduct their current atrazine review. But already we know they will have to answer some challenging questions, such as the ones that Yale University Professor David Skelly has posed. Skelly was appointed by the EPA to serve on a reviewing panel for a Hayes study. He has been publicly quoted as saying that one thing “missing from this story” of Hayes’ latest data is whether his findings, based on lab experiments, could be repeated outdoors, where amphibians actually live. We think that’s a good question, too.

Hayes the Anti-Atrazine Activist or Hayes the Scientist?

We would like to think a scientist approaches every research project in an impartial and balanced manner. But Dr. Hayes is different. He is a self-proclaimed anti-atrazine activist. He hosts an anti-atrazine website titled which urges readers to Take Action by writing EPA, Congress and the makers of atrazine. Dr. Hayes is a talented and convincing public speaker and even has an “Atrazine Rap” presentation on YouTube. Unfortunately, his gift of rhyme doesn’t keep his science in compliance.

What the regulators have said about Hayes’ research:

“no available proof for the hypothesis regarding the purported action of atrazine on the induction of aromatase (p19; SAP 2007)
“…atrazine does not adversely affect amphibian gonadal development.
…no additional studies are required ”
– U.S. EPA | p 114; USEPA 2007

“current data indicate that it is unlikely that atrazine is impacting adversely on Australian amphibian populations at current levels of exposure.”
– Australian APVMA | APVMA 2008, Australian Pesticides and Veterinary Medicines Authority is the Australian government authority responsible for the assessment and registration of pesticides and veterinary medicines.

“The work reported in the paper [Hayes et al. 2002] was apparently carried out with little regard for assessment of causality. Hence, the paper grossly overstates the potential effects on frogs and changes in populations based on the data given.”
– United Kingdom | Council Directive 91/414/EEC, Regulation 3600/92. March 2003

“Special Atrazine Review identified no concerns based on understanding of current and recent science.”
– State of Minnesota | Minnesota Dept. of Agriculture 2010