Center for Biological Diversity


For Immediate Release, December 14, 2015

Contact:  Dr. Tyrone Hayes, University of California at Berkeley, (510) 643-1055, tyrone@berkeley.edu
Dr. Nathan Donley, Center for Biological Diversity, (971) 717-6406, ndonley@biologicaldiversity.org
Caroline Cox, Center for Environmental Health, (510) 655-3900 x 308, Caroline@ceh.org

California Atrazine Proposal Ignores Science on Dangers to People, Wildlife

SACRAMENTO, Calif.— Scientists, including leading atrazine researcher Dr. Tyrone Hayes, called on California officials today to adopt a more stringent labeling requirement that would make it harder for products containing unsafe levels of atrazine — a harmful pesticide banned in Europe — to escape having to be labeled as known to cause reproductive toxicity in humans.

Hayes, along with the American Congress of Obstetricians and Gynecologists California Chapter and 19 other scientists, criticized California’s recently proposed “safe harbor level” for atrazine for its reliance on an unpublished 1996 study funded by the pesticide industry. “Safe harbor levels” are a threshold for determining when products like pesticides need to be labeled as known to cause harm. The Center for Biological Diversity and Center for Environmental Health also sent in a separate comment letter expressing additional concerns.

California’s proposal for atrazine ignores newer published studies, conducted by both independent and governmental entities, finding that levels of exposure in the state’s plan can cause serious health effects. The comment period for the plan closes today.

“Given the overwhelming evidence of unacceptable risk, I’m quite frankly surprised that atrazine is even still in use,” said Dr. Tyrone Hayes, professor and atrazine researcher at University of California, Berkeley. “The links to birth defects, prostate cancer and breast cancer in humans are all well supported by laboratory studies in animals. The manufacturer's attempts to bury these data and discredit the science should be a trigger for more careful agency review.”

Dr. Hayes’s research has shown that atrazine can chemically castrate and feminize male frogs at concentrations lower than the level allowed in drinking water by the Environmental Protection Agency. The “safe harbor” level that California has currently set for atrazine fails to provide adequate protections from this toxic pesticide because it is not based on the best available science. The nearly 20-year-old, industry-funded, unpublished study that California relied on was also used by the EPA to determine the concentration of atrazine that is considered safe for human exposure throughout the U.S., ignoring the body of evidence from independent and government researchers that indicates much lower exposures can cause serious health effects.

“The EPA has discounted high quality research, some of which was carried out by its own scientists, in favor of industry-funded studies,” said Dr. Nathan Donley, a scientist with the Center for Biological Diversity. “How is it even possible that government regulators are ignoring their own science to inform these important decisions?”

About 80 percent of studies that the EPA used in its analysis of atrazine were unpublished, did not undergo peer review, and were not immediately available to the public. At least half of the analyzed studies were conducted by scientists or organizations that had financial ties to atrazine.

“Most people think that the government tests pesticides for safety, but, in fact, it’s the pesticide companies that make money when their products are approved that conduct almost all of the safety testing,” said Caroline Cox, research director at the Center for Environmental Health. “So it's no surprise that they almost always find that their own products are safe — it's a clear case of the fox guarding the chicken coop.”

About 80 million pounds of atrazine are used in the United States each year, contaminating ground, surface and drinking water. Atrazine — or its primary degradate — was found in approximately 75 percent of stream water and about 40 percent of all groundwater samples from agricultural areas tested in an extensive U.S. Geological Survey study. In people, atrazine exposure may be linked to increased risks of thyroid cancer, reproductive harm and birth defects. For example, a recent study showed that children of mothers exposed to atrazine had an increased risk of a birth defect called choanal atresia, a narrowing or blockage of the back of the nasal canal that can be life-threatening in newborn infants. 

In wildlife, amphibians are particularly vulnerable to atrazine’s health effects because their permeable skins absorb contaminants from agricultural runoff and atrazine’s population-level impacts on these sensitive species are unknown. Under the terms of a historic settlement with the Center for Biological Diversity, the EPA must analyze the impacts of atrazine on 1,500 threatened and endangered species by 2020.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 900,000 members and online activists dedicated to the protection of endangered species and wild places.


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