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For Immediate Release, August 27, 2009

Contact: Jeff Miller, Center for Biological Diversity, (510) 499-9185

New Research: Herbicide Atrazine Linked to Cancer, Birth Defects,
Endocrine Disruption, and Endangered Species Impacts

SAN FRANCISCO— New research on birth defects at extremely low concentrations and documentation of widespread ground- and drinking-water contamination has strengthened the case for banning the toxic compound atrazine, the most commonly used herbicide in the United States. Atrazine is a widely used weed killer that chemically castrates male frogs at extremely low concentrations and is linked to significant human and wildlife health concerns, including endocrine disruption, birth defects, fertility problems, and certain cancers.

“It’s time to ban atrazine to protect our drinking water and our most imperiled wildlife,” said Jeff Miller, a conservation advocate with the Center for Biological Diversity. “There is no reason to continue use of this poisonous contaminant given the building evidence of harm to humans and endangered species.”

Atrazine is a potent chemical that is the most common contaminant of ground-, surface, and drinking water nationwide. Recent research published in peer-reviewed journals suggests that small amounts of atrazine in drinking water can be harmful at much lower concentrations than federal standards, and link the pesticide to birth defects, low birth weights, premature births, and menstrual problems. Previous research has provided evidence linking atrazine to prostate cancer and decreased sperm count in men, and higher risk of breast cancer in women.

Articles this week in the New York Times, Washington Post, and Huffington Post discuss how the Environmental Protection Agency is ignoring unsafe atrazine contamination levels in surface and drinking water in the Midwest and South. Agency documents show that numerous watersheds and drinking-water systems are contaminated with atrazine, which was banned by the European Union and in Switzerland, the home country of its parent company Syngenta, because of dangers to both people and wildlife.

Atrazine is linked to declines of endangered amphibians and fish in California such as the California red-legged frog, California tiger salamander, Delta smelt, coho and chinook salmon, and steelhead trout. Atrazine also harms many other endangered species throughout the country, including sea turtles in Chesapeake Bay, Barton Springs salamanders in Texas, endangered mussels in Alabama, shortnose sturgeon in Midwest waters, the Wyoming toad, and the Illinois cave amphipod.

Numerous studies have definitively linked pesticides and herbicides with significant developmental, neurological, and reproductive damage to amphibians. Pesticide contamination can cause deformities, abnormal immune system functions, diseases, injury, and death. Studies by Dr. Tyrone Hayes at the University of California show that atrazine is an endocrine disruptor that interferes with reproduction and “assaults male sexual development.” Dr. Hayes demonstrated that atrazine chemically castrates and feminizes male frogs at concentrations 30 times lower than levels allowed by the Environmental Protection Agency. Although exposure levels as low as 0.1 parts per billion (ppb) result in frog hermaphrodites, the agency’s atrazine criterion for the “protection of aquatic life” is 12 ppb.

Conservationists sued the Environmental Protection Agency in 2003 for failing to review the impacts of atrazine on several endangered species. The registration for atrazine was revised later that year, revealing the agency’s obeisance to the agrochemical industries it was intended to regulate. Despite numerous studies and overwhelming evidence linking atrazine to significant human and wildlife health concerns, the agency imposed no new restrictions on its use.

The Center for Biological Diversity has mounted a Pesticides Reduction Campaign to hold the Environmental Protection Agency accountable for pesticides it registers for use and to cancel or restrict use of harmful pesticides within endangered species’ habitats. Our 2004 report, Silent Spring Revisited: Pesticide Use and Endangered Species, details the decades-long failure of the agency to regulate pesticides harmful to endangered species. In 2006 the Center published Poisoning Our Imperiled Wildlife: San Francisco Bay Area Endangered Species at Risk from Pesticides, a report analyzing the agency’s dismal record in protecting Bay Area endangered species and the agency’s ongoing refusal to reform pesticide registration and use in accordance with scientific findings.

We and our allies have filed numerous lawsuits to force assessment of pesticide impacts on endangered species and prohibiting use of such chemicals within endangered species habitats until formal consultations with the U.S. Fish and Wildlife Service have been completed. In 2005, our lawsuit forced the Environmental Protection Agency to assess impacts of atrazine and five additional pesticides on the Barton Springs salamander in Texas. In 2006, we reached a settlement agreement that prohibits the use of 66 toxic pesticides in and near core California red-legged frog habitats. In 2009 we reached a proposed agreement restricting the use of 74 pesticides and evaluation of their impacts on 11 endangered species in the San Francisco Bay Area.

Although required by court order in 2003 to further assess atrazine, the Environmental Protection Agency entered into a private deal whereby the atrazine manufacturer Syngenta was allowed to conduct contaminant monitoring, assessing a mere 3 percent of the watersheds identified as “at risk” of atrazine contamination. A recent report by conservationists analyzing agency monitoring data reveals that the agency has been ignoring the atrazine contamination problem, and that the monitoring is misleading and its regulation insufficient. The monitoring programs were not designed to find the biggest problems, the screening levels are too permissive, and the monitoring ignores more than 1,000 vulnerable watersheds.

Resources on Atrazine:

Atrazinelovers – Dr. Tyrone Hayes’ web site informing the public about the dangers of atrazine

Hayes et al. 2006 - Pesticide Mixtures, Endocrine Disruption, and Amphibian Declines: Are We Underestimating the Impact?

Hayes 2004 -There Is No Denying This: Defusing the Confusion about Atrazine

Harper’s Magazine, August 2006 – US: It's Not Easy Being Green: Are Weed-Killers Turning Frogs into Hermaphrodites?

Innovations Report, February 2006 – Pesticide Combinations Imperil Frogs

Sierra Magazine, 2004 – A Frog Biologist Battles an Agrichemical Giant

The Center for Biological Diversity is a national nonprofit conservation organization with more than 225,000 members and online activists dedicated to the protection of endangered species and wild places.


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