PANNA: EPA Sweet on Atrazine



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EPA Sweet on Atrazine
March 31, 2005

As the spring herbicide application season gets underway, more calls are heard to limit atrazine, the most widely used agricultural chemical in the U.S. and a nearly ubiquitous contaminant of surface and ground water. Legislation to ban the herbicide was introduced in Minnesota for the second year in a row, and regulators in Australia are reconsidering approval of the herbicide. Meanwhile, on February 17, 2005 the Natural Resources Defense Council (NRDC) filed a lawsuit against the U.S. Environmental Protection Agency (EPA) for holding upwards of 40 private meetings with atrazine’s manufacturer, Syngenta, while the agency was conducting a special review of the herbicide to consider its impacts on amphibians and links to cancer in humans. That review resulted in EPA approving continued use of the herbicide in 2003.

The European Union has banned atrazine due to ground water contamination, and Syngenta has made alternative products available in some nations. In 2002 the herbicide was listed by the UN Environmental Programme as a globally important persistent toxic substance with the potential for regional transport. Measurable levels of the herbicide have been found in rain and fog in Europe as well as in the U.S., where atrazine has been detected at levels higher than EPA’s safety standard in the drinking water serving more than a million U.S. residents.

In Minnesota, where the herbicide is applied to 45% of the state’s corn acreage, data on surface water monitoring from the Minnesota Department of Agriculture (MDA) report atrazine in all regularly sampled rivers, with contamination in some rivers at levels presenting clear health risks to pregnant women and children. MDA sampling during spring and early summer rainy seasons for example, revealed atrazine in the Whitewater River ranging from 1.8 to 15.1 parts per billion (ppb) between 2001 and 2003, and measured levels in one season as high as 32 ppb. The EPA drinking water standard is 3ppb and the California standard for drinking water is 1ppb.

Two weeks ago the Minnesota House Agriculture and Rural Development committee rejected two bills banning atrazine, but supporters say they plan to re-introduce language phasing out the herbicide. The committee has not yet voted on a “Citizens Right to Know” bill that would allow citizen access to pesticide application data. Jannette Brimmer of the Minnesota Center for Environmental Advocacy highlighted the importance of the right to know legislation, “At a time when we are learning of chemically-castrated and hermaphroditic frogs, fish and birds, it is unacceptable that we currently have no way of accurately determining where, how much and what kinds of pesticides are being applied in Minnesota.”

In a recent article in BioScience, Dr. Tyrone Hayes, author of studies indicating that low levels of atrazine affect sexual development in frogs, analyzed several Syngenta-funded studies widely reported to dispute the results of his extensive laboratory and field research. In the article Hayes dryly notes that “data presented in these studies are not in disagreement with my laboratory’s peer-reviewed, published data” and points to careless animal husbandry practices and contaminated reference sites that produced data inappropriate for comparison with his published data.

In 2002, Dr. Hayes reported chemical castration (demasculization) and feminization of frogs at low but ecologically relevant concentrations of atrazine. This study, published in a peer reviewed scientific journal, was not the first performed by Hayes revealing atrazine’s effects. Earlier work done by Hayes and his laboratory with funding from Syngenta was disputed by the agro-chemical giant and not published. Hayes duplicated his work independently, examining leopard frogs (Rana pipiens) across a transect of the U.S. extending from Utah to the Iowa/Illinois border, and detecting frog abnormalities similar to those found in his laboratory in every site where atrazine levels were over 0.1ppb. When Hayes’ work was published, EPA was midway through a special review of atrazine. Syngenta continued to dispute Hayes’ findings while also offering him two million dollars to continue his research in “a private setting.”

In October of 2003 EPA ended its special review and allowed continued use of atrazine. Instead of addressing the water contamination issues, EPA developed an agreement with Syngenta to conduct a monitoring program in 40 watersheds, fewer than 4 percent of the 1,000 streams identified by the EPA as being at highest risk for atrazine contamination. Under this deal, Syngenta would then determine the effects and mitigation needed for the herbicide’s continued use.

EPA also reversed an earlier finding and concluded that atrazine was not likely to cause cancer in humans, despite the fact that atrazine has been strongly implicated as a human carcinogen. A number of studies have connected farmworker exposures with increased risk of prostate cancer, and atrazine water contamination with increased risk of breast cancer.

NRDC’s recent legal challenge to EPA bears a remarkable resemblance to a similar lawsuit filed more than 20 years ago by the environmental organization, also charging EPA with making sweet deals with industry. As that case progressed, EPA Administrator Ann Gorsuch resigned amid allegations of improper industry influence, and the agency agreed to a strict criteria of open and transparent decision making around the re-registration or “special review” of pesticides. Those restrictions forbade EPA to make a final decision based on negotiations with industry and required a balance of perspectives in committees of outside advisors. The NRDC lawsuit charges that EPA has ignored these regulations in its regulation of atrazine.

Sources: Tyrone B. Hayes, “There is No Denying This: Defusing the Confusion about Atrazine,” Bioscience, December 2004, Vol. 54, No. 12, pp 1138-1149; Pesticide Monitoring in Water Resources: Annual Data Report, February 24, 2005,; Press Release, Minnesota Center for Environmental Advocacy,; Press Release, Feb 17, 2005, NRDC,
Contact: PANNA.

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