Alex Avery, Director of Research and Education at the Hudson Institute’s Center for Global Food Issues, released a video criticizing new research by University of California Berkeley professor Dr. Tyrone Hayes alleging endocrine disruption in amphibians caused by the popular herbicide atrazine.
“For the last ten years I’ve been watching closely the research and activism of Dr. Tyrone Hayes from the University of California – Berkley. And for ten years Dr. Hayes has tried to claim that atrazine is an eminent threat to amphibian populations because it feminizes frogs at some, but not all, concentrations,†says Avery.
Avery points out that Dr. Hayes’ research is flawed due to the small sample size of the experiment. He cites several recent papers that have used sample sizes much larger and allowed the EPA full access to their research that contradict Hayes’ research, finding no impact on feminization of males. Avery goes on to criticize Dr. Hayes for releasing his findings “via press release orchestrated by environmental organizations instead of doing research by the book without bias.
We have to weigh one or the other. I don’t think Dr. Hayes has really stepped up to the plate. He continues to do research that according to the EPA is ‘insufficient’and ‘scientifically flawed.’ They [the EPA] also complain that Dr. Hayes would not share his raw data.
Finally Avery addresses Dr. Hayes research directly, asking if his research is correct then frog populations in areas where atrazine has long been used would not be thriving as many are today. He also refers to a Yale University study which found frogs in urban areas having more of a feminization problem than rural areas, where atrazine is used.
The New York Times pointed out that Avery’s non-profit employer has received funding from Monsanto Company, DowElanco and the Ag-Chem Equipment Company.
Please consider that there may be multiple factors adversely affecting frogs and some factors may produce a larger impact than others depending on the area (atrazine and other pesticides, PCBs, UV, fungus, habitat loss etc). There is a new book by Dr. Nancy Langston, Toxic Bodies, that I would add to your list of must-read books. She does a very nice job of explaining many of your questions and why old notion that “the dose makes the poison” does not apply to hormone disruptors. Remember that mortality is not the only end point to evaluate- we need to look look closely at endocrine and neurological effects that might cause harm without causing death.