Endocrinologist expert speaks against atrazine

January 11 2008

TERRE HAUTE • After Tyrone Hayes concluded his Indiana State University presentation with a rap to a standing-room only crowd, he urged the listeners to get politically involved • all in the name of science.

As the inaugural Diversity in Science speaker, Hayes, a developmental endocrinologist at the University of California at Berkeley, spoke about the effects of the herbicide atrazine, one of the most widely used pesticides in the United States, upon frogs. The speech titled, “From Silent Spring to Silent Night: Atrazine’s Impact on Environmental Health,” plays off of scientist Rachel Carson’s book “Silent Spring,” which documented the detrimental effects of pesticides, specifically on birds, and helped lead to the banning of DDT.

Rusty Gonser, assistant professor of life sciences, said his department and the office of diversity and affirmative action paired up to bring role models for students onto campus.

“We want to influence our students to show them what scientists are doing out there,” he said.

Hayes is just the person to do that, according to Gonser. Hayes’ studies have challenged the ecological safety of atrazine, and in doing so, he has taken on the company that manufactures it. While Hayes’ research has shown that the chemical affects amphibians’ reproductive organs, Syngenta Crop Protection, which manufactures atrazine, stands behind its product. In a letter received prior to Hayes' speech, the company cited a recent review by the Environmental Protection Agency.

Syngenta said EPA’s review, which used an independent scientific advisory panel, found no link between atrazine and frog deformities.

“EPA believes that no additional testing is warranted to address this issue," the agency said in a December “status update.” The science advisory panel’s final report and recommendations are due to be released later this month.

“Atrazine has been a vital tool for U.S. farmers for nearly 50 years because it is effective at controlling a broad range of yield-robbing weeds, is safe to the crop and fits in a variety of farming systems,” Timothy Pastoor, principal science advisor for Greensboro, N.C.- based Syngenta, said in response to Hayes’ appearance at ISU. “It has been proven safe to use based on the weight of evidence from thousands of studies and a 12-year special review by federal regulators.”

Hayes disagrees with those findings.

“I’m basically a little boy who likes frogs,” Hayes told students and faculty during the seminar.

One of the reasons he likes them is being able to see their metamorphosis as they change from tadpoles into frogs. Yet, because they aren’t protected in a shell, anything in the water can affect them, according to Hayes.

Americans use 80 million pounds of atrazine on their crops and it is affecting more than crops, Hayes said. Even though the EPA has approved its use in the United States, he pointed out that it is not used in Europe or other places.

“Atrazine is illegal in Angola,” Hayes said. “It could be the richest country in the world with its control of oil, gold and diamonds, except for its war. They can’t come together on that, but they know they don’t want atrazine.”

During his presentation, Hayes showed pictures of dissected deformed frogs, including one with two sets of testes and ovaries.

“This is not normal,” he said. “They should not have both testes and ovaries.”

Atrazine, he said, turns on an enzyme that changes testosterone into estrogen in male frogs. He also showed photos of male frogs growing eggs in their testes.

Frogs exposed to atrazine were also found to have suppressed immune systems and were unable to fight off basic infections or parasites.

“There’s a thought in science of don’t be an advocate,” Hayes said. “I’ve changed my mind.”

Pesticide is playing a harmful role in the lives of frogs, he said.

“When the environment’s health suffers, so will our physical health,” he said.

He urged attendees to write to their congressmen about atrazine and in support of bills that would ban the pesticide in the United States.

“You’ve got to get politically involved,” he said.

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Writer: Jennifer Sicking, Indiana State University assistant director of media relations, at 812-237-7972 or jsicking@isugw.indstate.edu

Photo: http://ISUphoto.smugmug.com/photos/241832427-D.jpg Cutline: Tyrone Hayes, a developmental endocrinologist at the University of California at Berkeley, laughed while speaking to a crowd at Indiana State University about the effects of atrazine upon frogs.

Photo: http://ISUphoto.smugmug.com/photos/241832433-D.jpg Cutline: Tyrone Hayes, a developmental endocrinologist at the University of California at Berkeley, spoke to a full auditorium classroom as the inaugural Diversity in Science speaker.

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Story Highlights

As the inaugural Diversity in Science speaker, Tyrone Hayes, a developmental endocrinologist at the University of California at Berkeley, spoke about the effects of the herbicide atrazine, one of the most widely used pesticides in the United States, upon frogs.

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