Air Date: Week of April 21, 2006

The European Union has banned one of the worlds most widely used pesticides. Atrazine in drinking water has been linked to prostate and breast cancer. Host Steve Curwood talks with Professor Tyrone Hayes of UC Berkeley about his research on the chemical's prevalence in the United States.

Transcript

CURWOOD: From the Jennifer and Ted Stanley studios in Somerville, Massachusetts, this is Living on Earth. I’m Steve Curwood.

The European Union has banned the herbicide Atrazine, effective next year, after finding it contaminated a number of drinking water supplies. The weed killer first came under scrutiny for its effects on frogs, and more recently has been linked to adverse affects on human health.

Some 70 million pounds of Atrazine are used in the U.S. each year, mostly on cornfields. After studying Atrazine, the Environmental Protection Agency decided not to ban it in the U.S., but says its research into the chemical continues.

Joining me now is Tyrone Hayes, a professor at UC Berkeley who’s done pivotal research on Atrazine. And he’s just back from Europe, we caught up with him at the airport. Professor Hayes, welcome to Living on Earth.

HAYES: Good to be here.

CURWOOD: So from your expertise, what’s your analysis of the science behind the EU’s decision to ban Atrazine?

HAYES: Well, there’s a great deal of data showing Atrazine is in fact an endocrine disrupter. In amphibians, Atrazine results in the demasculinization – chemical castration – of male frogs, and subsequent feminization. It produces hermaphroditic frogs, males with ovaries and eggs. And in rodents and humans Atrazine is associated with breast cancer and prostate cancer and low sperm count.

The European Union has a slightly different approach to regulating chemicals than the United States. It operates under the precautionary principle, which says that if there is the potential for a chemical to cause environmental and public health harm, then that chemical is regulated. And in the case of Atrazine, banned, because it’s found in the water.

The United States counts on the industry that produces the chemical to produce data to actually prove that the chemical’s harmful. There are states that have made some movements towards regulating Atrazine. For example, Wisconsin bans Atrazine county by county, depending on when it shows up in the water.

CURWOOD: Now, what about the exposures here in the real world. How much Atrazine has been found in U.S. drinking water? And how does that compare to what’s been found in Europe?

HAYES: I think the levels are about equal between the United States and Europe. The current drinking water standard in the United States is three parts per billion, and, particularly in the Midwest, that three parts per billion can be exceeded. But, in fact, we know now that Atrazine is biologically active as low as .1 parts billion. So that’s 30 times lower than the current drinking water standard in the United States.

CURWOOD: There’s a lot of concern about prostate cancer and breast cancer here. What relationship, if any, is there between Atrazine and those diseases?

HAYES: The relationship between Atrazine and prostate cancer and breast cancer is very significant. Experimental evidence in rodents show that Atrazine is associated with an increased incident of both prostate cancer and breast cancer. And correlational evidence in humans shows that people who are exposed to Atrazine have higher rates of breast cancer and prostate cancer.

In fact, if you feed a female rat Atrazine – her pups that she is suckling, her male pups, can develop prostate disease. So those effects of Atrazine are transferable even from the mother to the suckling pup.

There’s also studies showing that prostate cancer was increased in men who worked in a factory that produced Atrazine. The levels of prostate disease and prostate cancer were 8.4-fold higher than expected, and 8.4-fold higher than men who worked in the factory but were not exposed to Atrazine.

So given that Atrazine is the number one selling pesticide in the world, and given that breast cancer and prostate cancer are the number one cancers in men and women, respectively, then I think this is a big concern.

CURWOOD: How prevalent is the presence of Atrazine in U.S. drinking water supplies? Is this a problem for five percent of the country? Ten? Twenty? Fifty percent?

HAYES: You know, the bigger problems for Atrazine are in the Midwest, where it’s used mostly, so like Nebraska and Iowa, Indiana. The concerns are not just for people who live in areas where Atrazine is used. But people have to also understand that Atrazine travels quite far and can be found in areas that are even considered pristine. Both in Europe and the United States it’s been shown that Atrazine can be found as much as 600 miles from where it has been applied.

CURWOOD: So in your view is there enough evidence out there to ban Atrazine in the United States?

HAYES: Certainly, when you look at the environmental health risks and the public health risks and the prevalence of Atrazine in groundwater and drinking water, there’s cause for concern. When you consider on top of that the evidence in every animal class that’s been examined that Atrazine causes adverse biological effects, then this raises concern. Essentially, in the United States, we’ve put a price on our breasts, on our prostates, on our environmental health, and decided that the economic hit to banning Atrazine, that that concern exceeds our concern for environmental health and public health.

CURWOOD: Tyrone Hayes is a professor at the University of California at Berkeley. Thank you so much for speaking with me.

HAYES: My pleasure.

 

Links

Professor Tyrone Hayes Faculty Profile