Syngenta Terrorized Scientist for 15 Years to Quell Concerns About Atrazine

Story at-a-glance

  • Atrazine is the second most commonly used herbicide in the U.S. Europe banned it in 2005 due to suspected environmental damage and health concerns
  • Tyrone Hayes, a UC Berkeley professor, was hired by Syngenta to investigate the effects of atrazine on amphibians, but the company blocked the publication of his work when they didn’t like the results
  • Research shows atrazine triggers overproduction of estrogen and underproduction of testosterone, and it has been linked to deformities of the reproductive organs, several types of cancer and birth defects


This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.

By Dr. Mercola

With the advent of the "green revolution" starting in the 1930s, chemicals were widely embraced as the way to eradicate hunger and ensure abundant harvests. Pesticides and synthetic fertilizers were hailed as scientific marvels that afforded the Western world the highest standard of living the world had ever known.

In this chemistry-based model, every problem has a chemical solution: pesticides to kill pests, herbicides to address weeds, insecticides to get rid of specific insects, fungicides against mushrooms and fungi and synthetic fertilizers to promote growth.

All seemed well and good, but as the decades wore on, problems and drawbacks became apparent. Today, the hazards associated with pesticides have become quite obvious to anyone willing to look.

However, that doesn’t mean appropriate action is being taken to protect human and environmental health. On the contrary, the chemical industry has fought long and hard, often employing questionable methods, to hide the truth about many of these harmful chemicals; putting profit ahead of safety.

Atrazine — The Forgotten Toxin

Glyphosate, the active ingredient in Monsanto's Roundup herbicide, is the most used agricultural chemical in history. It finally got some serious media attention after the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) determined it is a probable human carcinogen.

Less notorious, but certainly no less harmful, is atrazine, the second most commonly used herbicide in the U.S. It’s widely used to combat weeds on golf courses, residential lawns and Christmas tree farms. It’s also used on half of all corn grown in the U.S.

Atrazine was approved for use in 1958, but has been banned in Europe since 2005 due to suspected health concerns and environmental damage, including the high risk of water contamination.

In the featured video, Tyrone Hayes, Ph.D., a UC Berkeley professor of integrative biology, explains how Novartis (which later became Syngenta) hired him to investigate the effects of atrazine on amphibians, and then blocked the publication of his work when they didn’t like the results.

The research showed that atrazine causes hermaphroditism in frogs (turning males into egg-laying females) by inducing an enzyme called aromatase, which causes overproduction of estrogen.

The voice box in male frogs also did not develop properly, indicating that testosterone was not being produced at appropriate levels for development. On the whole, the research raised serious questions about human health effects.

According to Hayes, atrazine may be involved in the development of breast cancer, for example, since many breast cancers are triggered by the overproduction of estrogen.

Hayes claims Syngenta initially tried to convince him to manipulate and misrepresent the data. Hayes refused, ultimately resigning from his contractor position with Syngenta after they refused to allow him to publish his results. He also was not allowed to discuss the data outside a closed panel of Syngenta employees.

Atrazine Is a Potent Endocrine Disruptor and the Most Common Water Contaminant

After resigning in November 2000, he obtained independent funding to repeat the research, which was subsequently published. Since then, he's built an educational web site dedicated to informing the public about atrazine.1 According to Hayes:

"Atrazine is the most common chemical contaminant of ground and surface water in the United States. It is a potent endocrine disruptor with ill effects in wildlife, laboratory animals and humans.

Atrazine chemically castrates and feminizes wildlife and reduces immune function in both wildlife and laboratory rodents. Atrazine induces breast and prostate cancer, retards mammary development and induces abortion in laboratory rodents.

Studies in human populations and cell and tissue studies suggest that atrazine poses similar threats to humans. The peer-reviewed scientific studies to support these statements are summarized and can be viewed as you navigate this website.”2

Hayes notes that despite all of these risks, atrazine use continues unabated, in large part due to powerful lobbying efforts by Syngenta to keep atrazine on the market. In 2005, Syngenta spent $250,000 on lobbying in Minnesota alone, to keep atrazine sales going.

As Hayes continued his research into atrazine, he became convinced Syngenta was trying to destroy his research and reputation. He claims they offered to purchase his research, and when he declined to sell it, Syngenta hired other scientists to refute his studies.

Syngenta Threatens to Have Hayes’ Family Raped

Just how serious Syngenta was in trying to thwart Hayes came out during legal proceedings over atrazine contamination. As reported by The New Yorker in 2014:3

"Syngenta's public-relations team had drafted a list of four goals. The first was to implement the standard corporate approach to bad PR, 'discredit Hayes.'

In a spiral-bound notebook, Syngenta's communications manager, Sherry Ford, who referred to Hayes by his initials, wrote that the company could 'prevent citing of TH data by revealing him as noncredible ...'

Syngenta looked for ways to 'exploit Hayes' faults/problems.' 'If TH involved in scandal, enviros will drop him,' Ford wrote.'"

According to Hayes, Syngenta employees even hacked into his email, and on a number of occasions issued verbal threats of sexual violence against him, his wife and his young daughter, if he didn’t stop talking about atrazine.

Syngenta Sued Over Atrazine Contamination

A class action lawsuit against Syngenta,4 which was settled in 2012, turned out a treasure trove of information about Syngenta’s activities, including how the company “sought to prevent the Environmental Protection Agency (EPA) from banning the profitable chemical,” Democracy Now says.

The lawsuit was brought by 20 water utility companies, which accused Syngenta of contaminating local water supplies. The lawsuit noted atrazine poses health risks to pregnant women and the environment, forcing the water companies to spend more money to filter out the chemical.

In the end, Syngenta agreed to pay $105 million to cover the costs of atrazine removal from affected water supplies. As part of the settlement agreement, Syngenta was allowed to plea "no liability." Since then, 1,085 other compensation claims over atrazine contamination have been filed against Syngenta.5

Atrazine Exposure Linked to Reproductive Problems in Mammals and Infants

Attorneys have also begun investigating cases involving birth defects thought to be the result of atrazine exposure. According to Hayes, more recent research published by an international team of scientists, including himself, shows atrazine causes sexual reproductive problems in a wide range of animals, including mammals, birds and fish, not just amphibians, which was the focus of his earlier research.

One study also linked atrazine exposure in utero to impaired sexual development in young boys, causing genital deformations, including microphallus (micropenis). The evidence6,7 also suggests atrazine exposure may contribute to a number of different cancers, specifically ovarian cancer, non-Hodgkin's lymphoma, hairy-cell leukemia and thyroid cancer.

Elevated concentrations of atrazine in drinking water have been associated with birth defects, including abdominal defects, gastroschisis (in which the baby's intestines stick outside of the baby's body) and others.

EPA Reassesses Atrazine

Syngenta and other atrazine proponents insist that atrazine is safe for the simple fact that it’s been used for over 50 years and even the Environmental Protection Agency (EPA) has supported its safety. However, that may soon change. On June 6, 2016, the EPA released a new risk assessment for atrazine,8 and it presents a far harsher view of the chemical.

It is currently up for public comment and is not expected to be finalized until 2017, but it may well lead to tighter regulatory limits and possibly even an eventual ban, based on the level of concern found. An EPA "level of concern" describes the threshold above which a chemical may be expected to cause harm.

The risk assessment concluded the chemical may cause reproductive harm to mammals, fish and birds, with the level of concern surpassed nearly 200-fold using real-world scenarios for mammals. For fish and birds, atrazine exceeded the level of concern by 62- and 22-fold, respectively. And this time, the EPA specifically cited Hayes’ research. Not surprisingly, the pesticide and agriculture industries are up in arms over the assessment. As reported by Reuters:9

“Syngenta, which is set to be acquired by Chinese state-owned ChemChina, said atrazine is safe and that the EPA report ‘contains numerous data and methodological errors and needs to be corrected.’ If the EPA's report is finalized as written, it could cause label restrictions so severe that they would ‘effectively ban the product from most uses,’ the Iowa Corn Growers Association said.”

Curious Conflict of Interest

Like Monsanto, Syngenta produces patented genetically engineered (GE) seeds, designed to tolerate the pesticides they sell. This is a clear conflict of interest, as their seed business is little more than a means to sell more pesticides.

Another particularly curious conflict of interest raised by Hayes relates to the fact that, up until the year 2000, Syngenta not only produced atrazine, which induces aromatase that causes overproduction of estrogen — an effect that could raise your risk of breast cancer — but the company also produced another chemical, letrozol, which has the converse effect.

It’s an aromatase inhibitor that blocks estrogen production, and letrozol was, and still is, a commonly used as treatment for breast cancer.

“[T]he company was simultaneously, in 2000, making a chemical that induced estrogen and promoted breast cancer, and making a chemical that blocked estrogen production and was used to treat breast cancer. So there’s a clear conflict of interest there.”

How to Protect Yourself From Atrazine and Other Pesticide Exposures

According to data from the U.S. Centers for Disease Control and Prevention (CDC), more than 75 percent of the U.S. population has detectable levels of pesticides in their urine, and unless you're a farmer, your diet is one of the most likely routes of exposure, along with your drinking water.10

Eating organic is one of the best ways to lower your overall pesticide burden. The largest study11 of its kind found that people who "often or always" ate organic food had 65 percent lower levels of pesticide residues compared to those who ate the least amount of organic produce. Organic produce also had, on average, 180 times lower pesticide content than conventional produce.12

That being said, not everyone has access to a wide variety of organic produce, and it can sometimes be costlier than buying conventional. Remember that eating vegetables, even if they're not organic, is better than not eating vegetables at all.

If you need to prioritize, refer to the Dirty Dozen list and buy organic as much as possible when you’re choosing foods that are listed as the most-contaminated. If you shop at farmers markets, which I strongly recommend, you can also ask the farmer directly about pesticide usage.

It's possible to find produce that is not certified organic that may still have a lower pesticide burden than typical conventional produce depending on the farmer. So if you can't find organic produce, look for a local farmer who has eliminated pesticide use (or uses a minimal amount of such chemicals).

Filtering Your Tap Water Is Important to Reduce Atrazine Exposure

Atrazine is the most commonly detected pesticide in U.S. water supplies, so I recommend filtering your tap water — both for drinking and bathing. To remove atrazine, make sure the filter is certified to remove it. Fortunately, since it is a relatively large organic molecule it is easily filtered by a quality carbon filter.

As noted by the (NRDC):13 "Consumers should make sure that the filter they choose is certified by NSF International to meet American National Standards Institute (ANSI) Standard 53 for VOC (volatile organic compounds) reduction and therefore capable of significantly reducing many health-related contaminants, including atrazine and other pesticides."

Finally, if you know you have been exposed to pesticides, eat fermented foods like kimchi. The lactic acid bacteria formed during the fermentation of kimchi may actually help your body break down pesticides. In addition, there is some evidence that the antioxidant lycopene, found in watermelon, tomatoes, red bell peppers and more, may protect against some of atrazine's toxic effects.14


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