You may not have heard of atrazine, but chances are it has been used as an herbicide—weed-killer—to help grow the food you eat. Atrazine is currently the second largest selling pesticide in the world.1 It is used primarily on corn in the United States, but it is also used to help grow sorghum, sugar cane, and Christmas trees. The United States Geological Survey estimates that 80 million pounds of atrazine are applied in the U.S., primarily in the corn-growing states of Nebraska, Iowa, Kansas, Illinois, Indiana, and Ohio.2 It is unfortunate that atrazine has been so popular with industrial-scale corn growers over the last 49 years given all of the negative affects associated with the weed killer.3 As an endocrine disruptor, scientists have published many studies indicating that it causes a range of reproductive problems, even at extremely low doses.4
Atrazine and the Environment
Among wildlife, fish and amphibians are the most vulnerable, as they spend their lives living in atrazine-laced waters. Tyrone Hayes, Professor at the University of California Berkeley has conducted research that indicates that exposing frogs to as little as 0.1 ppb (30 times less than the 3 ppb the EPA allows in our drinking water) can have detrimental health effects.5 Frogs reared in atrazine-laced water have growth and immunity problems, and in about a third of cases, these frogs suffer from malformed reproductive organs. About 10% of male frogs with this level of atrazine exposure are “chemically castrated,” and develop female sex characteristics. Not surprisingly, Hayes has become a big critic of Atrazine and Syngenta—the agribusiness company that manufactures the herbicide.6 His public e-mails7 and raps8 have created quite a stir in a field known more for strict peer review and conservative confidence intervals than politically charged controversy.
Professor Hayes with one of his frog “subjects.”9
Atrazine and Human Health
Given the way in which atrazine disrupts hormones, it is not surprising that a number of epidemiological studies indicate that there is a connection between exposure to the herbicide and reproductive effects in humans including increased risk of miscarriage,10 reduced male fertility,11 and increased chance of any birth defect.12 The evidence for the carcinogenic potential is also growing—exposure has been linked to elevated risk of breast and prostate cancer.13 Scientists are just starting to explore the potential for atrazine to act synergistically with other pesticides to increase their toxic effects, a frightening possibility, which would substantially increase the negative health potential of the herbicide.
Persistence in the Environment
Given the amount sprayed on crops every year in the U.S., it is not surprising that atrazine is now the most common pesticide contaminant found in ground and surface water in the country.14 From 2007 to 2010, the National Resources Defense Council analyzed water samples from surface and ground water in the Midwest and Southern United States. The analysis found that 80% of the water samples taken from 158 different public drinking water systems had levels of atrazine surpassing the EPA limit for drinking water contamination, and 80% of the watersheds sampled had high enough levels of atrazine in them to harm plants and wildlife. These results confirm an earlier study by the U.S. Geological Survey where scientists found that 75% of stream water and 40% of ground water in agricultural areas of the country had traces of atrazine.15 All in all, the U.S. Department of Agriculture estimates that atrazine makes its way into public drinking water more often than any other pesticide. An estimated seven million people were exposed to atrazine in their drinking water in the five years between 1998 and 2003.16
A U.S. Geological Survey map displaying the areas of the U.S. where atrazine levels in the groundwater are likely to exceed 3 micrograms / liter (the Maximum Contaminant Level established by the EPA). 17
It is also worth noting that atrazine is highly mobile and persistent in the environment. Studies have shown that atrazine can travel up to 600 miles in rainwater. Once applied to a field of corn in Nebraska, atrazine can make it all the way to the pristine reaches of rural Montana!18 Further, given the way that atrazine stays in the environment, it is likely that the herbicide could remain in places like Montana for generations to come. In France, atrazine can be found in groundwater, even though it has not been applied there in over 15 years!19
Why the Delay, EPA?
Atrazine was banned in the European Union in 2003 due to concerns about the herbicide’s tendency to taint water. That was 2003—nine years ago! Atrazine was even banned in Switzerland, the home of Syngenta.20
In the United States, the Environmental Protection Agency (EPA) reviewed atrazine in 2005 and found it safe to use. Since the 2005 reviews many independent lobbyists have demanded a re-review. The Natural Resources Defense Council obtained documents revealing that agency officials met privately with Syngenta more than 40 times while evaluating atrazine’s toxicity. And the Huffington Post Investigative Fund reported that fewer than 20 percent of the papers the EPA relied upon in its past decision-making were peer-reviewed, while at least half were conducted by scientists with a financial stake in the product.21 In 2009, the EPA formally announcing that it would revisit the decision to allow use of the toxic chemical. The review was initially slated to take a year, but nothing has been decided yet, here in early 2012.22
Despite the environmental and public health risks, atrazine is still used in the U.S. The reason for this may have more to do with economics than it does common sense. The corn lobby is strong in the United States. While atrazine may only increase corn yield by as little as 1.2%, corn farmers like atrazine because it increases yields and lets them cut back on plowing.23 Syngenta is not willing to give in easily either. The agri-giant spent $250,000 lobbying in Minnesota alone in 2005 to keep atrazine on the market there. Ultimately, whether or not atrazine is banned will likely depend on whether the public makes demands that are loud enough to out roar big Ag.
