Chemical Industry Pressures EPA to Protect Herbicide, not Wildlife

NOTE: The following is one of a series of case studies produced by the Union of Concerned Scientists' Scientific Integrity Program between 2004 and 2010 to document the abuses highlighted in our 2004 report, Scientific Integrity in Policy Making.

Despite compiling hundreds of pages of evidence documenting the harmful effects of atrazine, a commonly used weed killer, the Environmental Protection Agency (EPA) refused to regulate the herbicide. Atrazine has been found to cause severe hormonal damage to wildlife, including amphibians, reptiles and fish. The European Union banned the herbicide because of safety concerns in October 2003, but at almost the same time, the EPA decided to re-approve atrazine for continued use in the United States.

The Washington Post reported that a petition filed with the EPA by Washington lobbyist Jim J. Tozzi provided the main rationale for the "reregistration" of atrazine with no new restrictions.¹ Tozzi, working closely with atrazine's primary manufacturer, Syngenta Crop Protection, developed a two-pronged attack on the science that questioned atrazine's safety. First, the petition argued that hormone disruption, even when clearly proven in scientific studies, cannot be used as a reason to restrict a chemical's use, because the government has not yet settled on an officially sanctioned test for measuring such disruption. The EPA adopted this reasoning in their decision, stating: "The Agency's ecological risk assessment does not suggest that endocrine disruption, or potential effects on endocrine-mediated pathways, be regarded as a regulatory endpoint at this time."²

Secondly, the petition sought to cast doubt on independent scientific studies linking atrazine to endocrine disruption, citing a little known piece of legislation called the Data Quality Act.³ The Data Quality Act, which allows stakeholders to challenge the accuracy of information used in regulatory decision-making, was actually drafted by Tozzi and slipped into a 2000 omnibus spending bill without debate or comment. The Post reported that the Act has been primarily used by industry to challenge the basis for regulations.4

The ecological impact of atrazine has been widely studied. According to the Center for Biological Diversity, the herbicide has been linked to declines in sea turtles, sturgeons, mussels and various amphibians.5 Most notably, atrazine has been found to produce hormonally confused frogs, turning them "into bizarre creatures bearing both male and female sex organs."6 

Dr. Tyrone B. Hayes of the University of California at Berkeley, originally hired by the chemical company Syngenta to review studies to help certify the herbicide for re-registration with the EPA, was at first surprised when he found that African clawed frog tadpoles were "chemically castrated" when exposed to even trace amounts of atrazine – levels one-thirtieth the amount currently permitted in US drinking water. Hayes’ findings were published in both Nature7 and the Proceedings of the National Academy of Sciences.8 

Hayes, who eventually resigned from the Syngenta review panel out of concern that his worrisome lab results were being buried, later charged that industry-supported scientists produced "a number of studies that were purposely flawed and misleading, and that changed the weight of the evidence."9 The two remaining members of Syngenta's atrazine review panel claimed that they had each tried but failed to replicate Hayes' data.10 In the scientific world such a claim is an insult or worse, implying that the original experiment may have been dishonest or flawed. In this case, the two scientists had both experienced difficulties raising the frogs—many of which died before metamorphosis because of being overcrowded and underfed. One scientist reported that he had contaminated the water with too much atrazine.

In other words, the new studies did nothing to disprove Hayes' results,11 which have been "echoed by at least four other independent research teams in three countries."12 When Hayes offered to help the Syngenta panel members and the EPA repeat his experiments to see for themselves whether atrazine posed a danger, the EPA declined.13 Nonetheless, the failed studies served to bolster the argument that the science linking atrazine to hormone disruption was uncertain. 

The EPA, however, did not only deem the atrazine data inconclusive; the agency allowed the chemical industry to effectively set the course of future action. As the Post reported, "in closed meetings—details of which the EPA has declined to release—company representatives and EPA officials worked out a plan to avoid tighter restrictions."14 Independent scientists and environmental groups were excluded from these negotiations. The Center for Biological Diversity reports that in the final deal, continued oversight of atrazine will be provided by atrazine manufacturers, who will be responsible for monitoring three percent of "at risk" watersheds.15 

The Natural Resources Defense Council sued the EPA over its approval of atrazine, saying that with the decision to re-register the herbicide, the EPA effectively bought into the chemical industry's effort to obscure perfectly clear science. Jennifer Sass, a scientist with the Natural Resources Defense Council, charges that the negotiated settlement went forward without any "scientific rationale."16 By accepting suspect industry science, minimizing well regarded and peer-reviewed scientific studies, and putting the chemical industry in charge of future data collection, the Bush administration showed its disregard for independent science.

1. Rick Weiss, “‘Data Quality’ Law is Nemesis of Regulation,” The Washington Post, 16 August 2004, accessed 21 September 2006.

2. Environmental Protection Agency, “Interim Reregistration Eligibility Decision for Atrazine,” January 2003, Pg. 73, accessed December 11, 2006.

3. Weiss.

4. Ibid.

5. “The Environmental Protection Agency’s Failure to Protect Endangered Species and the Public from Harmful Pesticides," Center for Biological Diversity, accessed 21 September 2006.

6. Weiss.

7. Hayes, T., et al. 2002. Herbicides: Feminization of male frogs in the wild. Nature 419: 895, subscription required.

8. Hayes, T., et al. 2002. Hermaphroditic, demasculinized frogs after exposure to the herbicide atrazine at low ecologically relevant doses. Proceedings of the National Academy of Sciences 99: 5476.

9. Weiss.

10. William Souder, “It’s Not Easy Being Green: Are Weed-killers Turning Frogs Into Hermaphrodites?Harper’s Magazine, August 2006, accessed November 16, 2006.

11. Souder.

12. Weiss.

13. Souder.

14. Weiss.

15. Center for Biological Diversity.

16. Weiss.



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