January 11 2008
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, â€œFrom Silent Spring to Silent Night: Atrazineâ€™s Impact on Environmental Health,â€ plays off of scientist Rachel Carsonâ€™s book â€œSilent Spring,â€ 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.
â€œWe want to influence our students to show them what scientists are doing out there,â€ he said.
Hayes is just the person to do that, according to Gonser. Hayesâ€™ studies have challenged the ecological safety of atrazine, and in doing so, he has taken on the company that manufactures it. While Hayesâ€™ research has shown that the chemical affects amphibiansâ€™ 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 EPAâ€™s review, which used an independent scientific advisory panel, found no link between atrazine and frog deformities.
â€œEPA believes that no additional testing is warranted to address this issue," the agency said in a December â€œstatus update.â€ The science advisory panelâ€™s final report and recommendations are due to be released later this month.
â€œAtrazine 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,â€ Timothy Pastoor, principal science advisor for Greensboro, N.C.- based Syngenta, said in response to Hayesâ€™ appearance at ISU. â€œIt 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.â€
Hayes disagrees with those findings.
â€œIâ€™m basically a little boy who likes frogs,â€ 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 arenâ€™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.
â€œAtrazine is illegal in Angola,â€ Hayes said. â€œIt could be the richest country in the world with its control of oil, gold and diamonds, except for its war. They canâ€™t come together on that, but they know they donâ€™t want atrazine.â€
During his presentation, Hayes showed pictures of dissected deformed frogs, including one with two sets of testes and ovaries.
â€œThis is not normal,â€ he said. â€œThey should not have both testes and ovaries.â€
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.
â€œThereâ€™s a thought in science of donâ€™t be an advocate,â€ Hayes said. â€œIâ€™ve changed my mind.â€
Pesticide is playing a harmful role in the lives of frogs, he said.
â€œWhen the environmentâ€™s health suffers, so will our physical health,â€ 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.
â€œYouâ€™ve got to get politically involved,â€ he said.
Writer: Jennifer Sicking, Indiana State University assistant director of media relations, at 812-237-7972 or firstname.lastname@example.org
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.
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.