ngin - Norfolk Genetic Information Network

31 July 2002


Biotech company Aventis has repeatedly claimed that their glufosinate ammonium (GA) weedkiller,  designed for use with crops being trialled here like their GM maize "has a  significantly better environmental profile than atrazine", and, "is not as mobile in the soil as atrazine, and so will not have the same effects on watercourses as atrazine"

But while Aventis's GM maize has been promoted in the UK as a means of getting away from the use of atrazine, in reality, atrazine is the chemical making up the biggest component in the mix US farmers are having to use to get sufficient weed control with Aventis's GM maize.
[see the transcript of Newsnight's 'weeds fight back' report]

It is also the most commonly detected pesticide in ground and surface water in the United States. And now a major new study has confirmed the finding that atrazine at extremely low levels, much as can be found in ground water, can cause severe hormonal disruption in frogs, such as forcing a male frog's testes to make female eggs instead of sperm.

The article below, which reports on a remarkable researcher as well as his findings, notes that, "Such shocking results, caused by dosages 30 times lower than U.S. Environmental Protection Agency limits of 3 parts atrazine per billion parts of water, may have serious implications for humans, many experts believe."


Research on the effects of a weedkiller on frogs pits hip Berkeley professor against agribusiness conglomerate

By  William Brand

The Oakland Tribune, Sunday, July 21, 2002

[image: TYRONE B. HAYES, an assistant professor at the University of California, Berkeley, discovered that low doses of atrazine -- a common weed killer -- causes hormonal changes in frogs.]

BERKELEY - The rollicking, hilariously lame lyrics of Walt Disney's "Jungle Book'' blast from the speakers in assistant professor Tyrone B. Hayes' biology lab at UC Berkeley early one weekday morning.

Hayes, who prefers jazz when he's relaxing at home in Oakland with his wife and two kids, quickly turns down the volume. ``Who picked this music,'' he asks with a grin.

Around the crowded lab, every hand goes up.

Casual is the rule in this lab. This day Aaron Vonk, Hayes' research assistant, wears a tropical sun hat. A couple of students boogey down the aisle in sync with the music, carrying frog tissue samples to examine under a high-powered microscope.

But beneath the loose atmosphere, there's some serious headline-making science going on here.

This is the lab that discovered that extremely low doses of atrazine, the world's top-selling weed killer, creates horrid, hormonal changes in frogs.

The pesticide can deform their sex organs, give bullfrogs female voices and create hermaphrodites - creatures with both male and female sexual characteristics.

Such shocking results, caused by dosages 30 times lower than U.S. Environmental Protection Agency limits of 3 parts atrazine per billion parts of water, may have serious implications for humans, many experts believe.

Some suggest the discovery may lead to more studies and eventually to a sweeping reevaluation of the usefulness and danger of chemical weed-killers.

The frog discovery pits Hayes, who will be 35 in two weeks and wears dreadlocks and an earring, and his young researchers against a multi-national cadre of scientists and executives at Syngenta, one of the largest agri-business conglomerates in the world.

As the Environmental Protection Agency this summer considers placing tougher restrictions on atrazine, Syngenta has submitted its own study, one that contradicts Hayes' test findings.

Syngenta said three separate studies by university scientists, commissioned by an outside company for Syngenta, have been unable to duplicate the results of the Hayes study. At levels of atrazine used by Hayes, the studies could not duplicate the same abnormalities found in the Hayes study, Syngenta said. The new studies are part of an intensive and ongoing research effort by a panel of eight scientists to examine the response of fish, amphibians and reptiles to atrazine, Syngenta said.

The studies have not yet been published in a scientific journal, but at least one currently is under peer review by other scientists, the company said.

EPA spokesman Dave Deegan said the agency may hand the issue to an expert science panel for a recommendation.

And though he disputes Syngenta's new study, Hayes also worries that pressure from the chemical industry may cause the EPA to back off. He said he hopes that doesn't happen, because atrazine contamination is serious.

"It doesn't take a rocket scientist to figure out what's happening," he said. "We're dealing with a chemical that can force a male frog's testes to make female eggs instead of sperm," Hayes said.

"Frogs are a good indicator of problems in the environment. They're a guardian in front of our house. They tell us what is happening,"' he said.

"DNA is the same in frogs, in reptiles, mice, rats, cats, dogs and humans."

Five years ago, Hayes studied atrazine under commission from Novartis, which after a merger became Syngenta. But he soon realized that examining the effect of high doses of atrazine on frogs was useless. "At high levels of atrazine, a frog's body just shuts down," Hayes said.

Because the company wasn't interested in a low-dosage study, Hayes said he and his lab workers decided to go it alone.

Since then, Hayes and his researchers - many are students who work without pay - have persevered without major funding. The World Wildlife Fund pays for their supplies and lab space; the National Geographic Society covers their field trips.

Hayes has submitted grant applications to the National Institutes of Health, the National Science Foundation and the EPA.

Though humans aren't as exposed to atrazine as frogs are, the toxic weed-killer is widely used in agriculture and on fancy lawns and golf courses. People can even buy weed-killers with atrazine as the active ingredient at garden stores.

The pesticide is heavily used in the Midwest, where it has been found at high levels in well water. The EPA now prohibits human use of water with atrazine levels higher than 3 parts per billion.

Atrazine studies:

Hayes' first study, published in April, used laboratory frogs. He's now about to publish a wider study, based on frogs gathered from around the country, which apparently confirms findings of the earlier study.

Atrazine has been closely studied by a number of scientists and has been regulated in an increasingly strict fashion since the 1980s. It is the most commonly detected pesticide in ground and surface water in the United States.

It has been linked at high dosages to breast and other cancers. Problems with frogs have been widely researched and new reports come in constantly. However, the Hayes study is the first to examine the effect of atrazine at extremely low levels, much as it is found in ground water in some areas.

"When I give a talk on this,'' Hayes said. "I hold out a dish with five grains of salt and explain that the amount of atrazine we give the frogs that causes problems is 5,000 times less - 0.1 microgram."

A microgram is one-millionth of a kilo, far less than the 3 parts per billion the EPA currently allows in human water supplies.

In Gainesville, Fla., University of Florida zoologist Louis Guillette agrees with Hayes' conclusions.

A Guillette study, published in 1997, reported male alligators found in a lake near Orlando had testosterone levels as low as a typical female alligator. The lake had been heavily inundated with pesticides, including atrazine, from farm runoff and a chemical spill.

"All these studies are a red flag," Guillette said. "Something needs to be done, and I don't believe the chemical industry will regulate itself."

Distinguished teacher:

Hayes is up to the challenge of taking on the chemical industry, with the help of researchers in the battlefield that is his laboratory. The University of California, Berkeley this year named him a distinguished teacher, an honor accorded only a handful of faculty members.
It was richly deserved, says integrative biology professor Robert Full, whose lab is down the hall.

"Besides being one of the best scientists in his field, he's able to draw in undergraduates into his research lab and let them help him make cutting-edge science discoveries," Full said.

"He's amazing," Full added. "We taught a course together for years. I never met anyone more engaging and more excited about his subject. He does it by relating biology to his life and his family."

Full recalled how Hayes connected a lecture on the way kidneys work to a question his youngest child once asked. His daughter Kassina, now 6, wondered why she didn't urinate very much in the desert.

The answer: You dehydrate in the heat, your blood becomes saltier and your body starts conserving water.

By the end of that lecture, every student understood precisely how the kidneys function, Full said. "Now, that's teaching."

All this from a kid who grew up in Columbia, S.C., fascinated by the frogs he found in the nearby Congaree swamp. The kid with a love of frogs went on to Harvard and became a biologist.

But it wasn't exactly an easy transition, Hayes admitted.

His father didn't finish high school, his grandfather never made it to high school, and Harvard for him was pure serendipity.

"I got high test scores, but I only applied to one college: Harvard,"

Hayes said. "It wasn't arrogance. It was ignorance.

"I used to watch this sitcom called Green Acres. That's how I'd heard of Harvard." That's the school Douglas in Green Acres went to, the one Hayes thought was so prestigious.

Much later, when he had graduated from Harvard and received his Ph.D in integrative biology from UC Berkeley, Hayes' parents told friends he was a medical doctor. They wanted people to understand he was doing something prestigious, he said. To them, the only prestigious doctor was an MD.

It's no wonder the idea of an African American being a scientist is foreign, he said. "When kids draw a picture of a scientist, they don't use a brown crayon.''

At UC Berkeley, fewer than 1 percent of scientists are African American. Across the United States, only 2.69 percent of scientists, physicians and engineers on university faculties are African American, according to the National Science Foundation.

Hayes said he once spoke at a Pan-African conference in Africa and was the only black scientist on the panel.

When Hayes finally began to receive nationwide publicity, family members understood at last that there are other "docs" as prestigious as MDs.

Attending Harvard as an African-American kid from a public school in South Carolina was difficult.

"I was one of those students who screwed up and I was on the verge of getting kicked out. I ended up living with three other black men, which in some ways was more difficult.

"They were all from educated families; they all had gone to private schools"' Hayes said, noting his background and experience was totally different.

He said even those guys didn't really fit in at Harvard in the mid- 1980s."So their reasoning was, if we don't fit in, we're gonna' make sure everybody knows our situation. There was a lot of drinking and partying, and my grades suffered," he said.

What saved him was a work-study job in a biology lab and a professor who took an interest in his fate. He moved onto campus, forged himself a study space in the lab and began to realize he might be a scientist someday.

He came to Berkeley for graduate study, because an African-American science major he had met at Harvard, Scott Edwards, was there.

Hayes said his experiences have given him perspective. Now, he likes to pluck kids from every ethnic background who are floundering academically from despair.

"Half my students are straight-A students and half are or were on the verge of being kicked off campus," he said. "My students have gone everywhere, to Harvard, Stanford, Johns Hopkins, to law school, and now you can't tell which ones were the screw-ups."

He said he works hard to encourage African American and other students of color to succeed. Four of the co-authors on the Atrazine paper are African American. That's pretty much a first in American science, he said.

"Ten percent of the kids I teach in my classes are African American,'' he said. "One of my students told me it makes a big difference to be sitting with other students who are black. He said it gave him some legitimacy."
Hayes said some suffer from subtle forms of self-doubt. "One of my black female students came to me and said she was worried because she just wasn't a good student," Hayes said. "Hands down, she actually was my top student."

He said the student felt that way because she had never been asked to join a good study group and thus didn't feel legitimate. ``Problems can be that complex and they can be fixed."

Hayes serves on a number of scholarship committees for that reason. "What happens is that when kids get into difficulty, the first thing that happens is that their scholarship is threatened. That's their support; they need it," he said.

Hayes said he tries to find out what's wrong. Some kids have incredible things happen to them, then freak out and let their studies slide.

Hayes said he also takes great pride in the diversity of his lab workers. "We have a white blond from North Carolina who just converted to Islam. We have a refugee from Vietnam.

"We celebrate the holidays of everyone. We have four or five independence days - some from countries I'd never even heard of.

"Our big joke is there are no majorities. We've never had more than two or three of any ethnicity."

But liking frogs is a plus.

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