The west branch of the Nishnabotna River runs within four miles of Ron Rosmann's farm and pastureland, so he was dismayed when he saw it on a list of dozens of watersheds in the United States that have been contaminated with a weed-killer called atrazine. Dismayed, but not surprised. He knows neighboring farms spray atrazine, and in April the rain washes it from the fields into the river. Perhaps fortunately, his own land is tucked within a bordering watershed not mentioned in NRDC's report Atrazine: Poisoning the Well.

Rosmann has read of animal studies linking atrazine to developmental disorders and other defects. Scientists suspect it is also linked to cancer and reduced fertility in people, though the product's manufacturer disputes the claim. It is banned in the European Union but remains the second most widely used weed-killer in the United States. “I find it all extremely alarming that this has been going for so many years. There have been attempts to regulate atrazine, but to no avail,” Rosmann says. Atrazine and other chemicals are “part of this complex modern, so-called better system of agriculture,” he continues. “And this industrial type of farming has largely destroyed communities, according to sociological studies.” Rosmann and his father used atrazine no more than three or four times before becoming alarmed enough about the effects of pesticides to stop spraying them in 1973. In 1983 Rosmann took up organic farming practices, and he was certified in 1994.

Unacceptable Levels
Atrazine has been leaching into rivers, lakes, reservoirs and even tap water for decades. It is most prevalent in the waterways and faucets of the American South and Midwest, where it runs off cattle pastures and fields of corn, sorghum and other crops. But it is also applied to roadsides, lawns and golf courses around the country. The government set limits on acceptable levels in our drinking water and in the environment, but NRDC's report suggests that our exposures are higher than previously assumed.

Invoking the Freedom of Information Act, NRDC obtained records compiled by the Environmental Protection Agency (EPA) on atrazine in tap water and in watersheds. For drinking water, the EPA has set a legal limit of 3 parts per billion (ppb) calculated as an annual average, and its quarterly sampling has shown that water around the country is within that limit. Mae Wu, one of the NRDC study's authors and a lawyer for the organization, found that the EPA does not take seasonal atrazine spikes into consideration and is “ignoring the fact that we see really high levels of atrazine in our drinking water and watersheds.” During peak seasons when rain runs off fields, the concentration of atrazine in a watershed can rise to hundreds of ppb. Even drinking water contamination can far exceed 3 ppb for a few days or weeks but still not exceed the annual average legal limit.

The EPA has heard these charges. “The Obama EPA will take a hard look at atrazine and other substances,” says Steve Owens of the EPA's Office of Prevention, Pesticides and Toxic Substances. “If the science demonstrates risks of concern, we stand ready to quickly implement the necessary restrictions to protect people and the environment.” A review has already begun, according to a spokesperson for the EPA.

Hormonal Effects
Animal studies have shown that atrazine affects the endocrine system, inducing the production of female sex hormones and restricting the production of male sex hormones. Aquatic animals that live in atrazine-contaminated water show severe abnormal development of reproductive organs, including males with eggs in their testes and hermaphrodites. Jennifer Sass, a senior scientist with NRDC, details atrazine studies in a Switchboard blog post.

Though atrazine's effects on the human hormone system have not been as well studied, we know that its hormonal effects are not restricted to amphibians, according to Tyrone Hayes, a professor of integrative biology at the University of California at Berkeley, who led studies of the weed-killer. “It's universal,” he says, “shown in everything from alligators to turtles, fish, frogs, rats, human cell lines—you name it, atrazine induces estrogen production.” Increased estrogen, in turn, is linked to reduced sperm quality and breast cancer in women, but there have been few studies of atrazine's effect on human cancer rates. “If we're seeing high enough levels in rainwater and runoff to cause problems in animals, then we should be concerned,” Hayes adds. Young children, human fetuses and those with estrogen-sensitive breast cancers may be the most vulnerable, according to Hayes and Sass.

For its part, Syngenta, one of several atrazine manufacturers, has been working to educate farmers in the responsible use of the chemical. In part because of its efforts, atrazine levels in surface water are falling, says Steven Goldsmith, a communications manager for the company. Referring to a study that Syngenta carried out at the request of the EPA, published last year in the journal Toxicological Sciences, Goldsmith notes, “We've learned that atrazine, even at the slightest levels sometimes found in water, has no effect on the normal development of frogs.”

Community Options
The most exposed are those who handle pesticides professionally: farmers, lawn-care professionals and workers in pesticide-manufacturing plants. To replace pesticides, Rosmann rotates and diversifies his crops and livestock and plows his fields sparingly (once every six years) using a method called ridge till. He cultivates the same crops as his neighbors—corn and soybeans—and the same livestock—cattle and swine—organically, enjoying comparable yields, spending less money and earning more on his sales. “I always go with the adage that the more you spray the more you have to spray," he says, "because it's pretty much non-selective. They kill the good along with the bad,” he adds, referring to the elimination of helpful insects and soil microbes that keep pest levels down naturally. 

City utilities have also responded to concerns about atrazine. A water district in Iberville parish, Louisiana, outfitted its filters with activated carbon to remove the high levels of the chemical during the rainy season, according to utilities department manager Brian Berthelot. His district was named in NRDC's report as one of those with high levels of atrazine in both surface and treated drinking water during March 2004, a peak month for atrazine runoff. Officials were likely alerted to the high atrazine level after the test, Berthelot said, and responded by installing the activated carbon. “I don't really know the effects of [atrazine], but I'm sure it's something you don't want in your drinking water,” he says.

What You Can Do
Contact your health department for information about atrazine levels in your water, then submit what you learn to NRDC to help make your drinking water safer.

If your water does have high levels of atrazine, you may filter it out using activated charcoal, which removes certain chemicals, heavy metals and some bacteria. Always be sure to select filters certified by the National Sanitation Foundation; NRDC's water filter recommendations may be found at Fresh From Your Faucet

Although there is no indication that it includes atrazine, bottled water is not as well regulated for contaminants as tap water and may not even be filtered, Mae Wu says. So the best solution for consumers is to use a filter.

Photo credit: / CC BY-NC-ND 2.0


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