Atrazine: Science under siege

Drinking water

Atrazine. It's in our lakes, streams and drinking water at levels that make a difference to human health. Scientists link exposure to increased risk of birth defects, infertility and possibly cancer.

Who's responsible? The Syngenta corporation — the world's largest pesticide company. They're working overtime to promote and protect their flagship product in the U.S., despite the fact that it's long been banned in their home county of Switzerland. Syngenta has intimidated scientists, pressured regulators and paid an economist to manufacture faulty studies — all to keep an unnecessary product on the market.

Contaminating U.S. waterways

Atrazine is found more often than any other pesticide in U.S. groundwater. The weed killer is one of the most widely used pesticides in the U.S. — and the world. More than 76 million pounds are used in this country each year, mostly on corn fields. Smaller amounts are used on other crops too, from sugarcane to cauliflower to Christmas trees.

Atrazine is good at killing weeds in part because of its stability; it can stick around for up to 100 days in the soil. This also makes it a pollution problem. Once it leaches into groundwater, it can remain there for decades.

Families in the Midwest who get their drinking water from shallow wells are especially vulnerable

Found in water throughout the Midwest, atrazine shows up in wells in agricultural communities and in pristine lakes and rivers. Drinking water contamination levels typically spike in spring and early summer, as rains flush the freshly applied herbicide. One recent study shows that atrazine also evaporates into the air after application, in a process called volatilization drift. It can then settle back into waterways.

USDA scientists found the herbicide in 94% of the drinking water tested in 2008.

Health effects in the heartland

Atrazine is an endocrine disruptor. This means that micro-doses can have large, irreversible effects that we are just beginning to understand. New studies link low-level exposure to birth defects, delayed puberty and infertility — all of which are on the rise. Higher cancer risk and environmental toxicity are also of concern.

  • Birth Defects: Infants concieved during atrazine spray season are more likely to be born with birth defects. Research shows that even low levels of exposure during pregnancy may be problematic; the third trimester appears to be most critical.
  • Cancer: Atrazine may increase risk of breast and prostate cancer. Though some studies have not found a link, the recent President's Cancer Panel Report calls atrazine a possible carcinogen.

Scientists report that for atrazine, timing of exposure may be more important than exposure levels, and interaction with other pesticides may make health harms more severe.

Evidence of environmental effects is also strong and growing. Recent studies show that atrazine causes genetically male frogs to become anatomically female through a "chemical castration" effect.

 

Chart atrazine and birth defects

Science under siege

During EPA's 2003 review of atrazine, Syngenta representatives held more than 50 closed-door meetings with regulators. In 2011 the company planned a PR campaign to undermine the court that is hearing a case against it in Illinois.

Syngenta has intimidated scientists & pressured policymakers

Syngenta has actively attempted to suppress science related to atrazine’s environmental and health problems. Scientists Tyrone Hayes and Paul Wotzka have faced retaliation for speaking publicly about their findings on atrazine.

In October 2009, EPA officially reopened its examination of health and environmental risks of atrazine, in response to new emerging science. PAN and Midwest farmer groups are closely tracking the review to demand a transparent, science-based process this time around. The review will conclude in late 2011.

Farming without atrazine

On-the-ground evidence proves there are many ways to produce corn without relying on Syngenta’s controversial herbicide.

Farmers in states like Minnesota are using innovative production systems to prove that a good corn crop can be raised atrazine-free.

Farmers like me are on the front line when it comes to the health risks of a chemical like atrazine. - Paul Sobocinski, Minnesota farmer

Corn yields and acreage have actually gone up in Germany and Italy since those countries banned atrazine in 1991. According to recent analyses, dropping atrazine completely from U.S. corn fields would result in yield losses of approximately 0 to 1%, much lower than industry estimates.

Practical, farmer-oriented information is increasingly available for producers seeking alternatives.

Related Publications

publications-syngenta-atrazine.jpg
The Syngenta corporation invented the herbicide atrazine and is its primary manufacturer. The corporation is certainly one of atrazine’s most ardent defenders and promoters. One of the most commonly detected pesticides in U.S. ground and surface water, many scientists are increasingly concerned about the human health and ecosystem impacts of atrazine. Atrazine is a known “endocrine disruptor” that is linked to reproductive harm and cancers. This report offers a review of the... Read more

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Research

Agrichemicals in surface water & birth defects, Winchester et al, 2009.  Acta Paediatrics

Atrazine & feminization of male African frogs
, Hayes TB, et al, 2010. National Academy of Sciences

Herbicide exposure in Indiana & preterm delivery, Ochoa-Acuña et al, 2009. Env'tl Health Perspectives

Economics of atrazine, Frank Ackerman, 2007. Int'l Journal of Occupational & Env'tl Health 

Prenatal atrazine exposure & adverse birth outcomes, Chevrier et al, 2011. Env'tl Health Perspectives

PAN Analysis

GroundTruth blogs on atrazine

GroundTruth blogs on Syngenta

Health Effects of Atrazine, PAN fact sheet

PAN’s Atrazine resource page

The Syngenta Corporation & Atrazine: The Cost to the Land, People & Democracy, 2010

WhatsOnMyFood? data on atrazine in drinking water

Resources

Atrazine: Alternatives to a Controversial Herbicide, Land Stewardship Project

Atrazine fact sheet, Beyond Pesticides

Atrazine updates, US Environmental Protection Agency webpage

Into the Mouths of Babes: Health Effects of Atrazine, Environmental Working Group

Still Poisoning the Well, Natural Resources Defense Council

Toxics on Tap: Pesticides in California Drinking Water Sources, CalPIRG