Atrazine has been on our radar for years. This lab-made herbicide is one of the most widely used in the United States. Many people have pushed against it over the last several decades—a good thing, given how studies have shown that atrazine poses numerous threats to our health. When a substance holds even a remote chance of a risk to our well-being, we feel it's critical to flag it. Especially one of which more than 70 million pounds are applied to American crops yearly.

But there's even more to atrazine's story: proof of how far behemoth pesticide manufacturers will go to gaslight the public and the scientists looking out for our best interest.

Atrazine: an Herbicide Takes Flight

Swiss scientists introduced atrazine into the marketplace in the late 1950s. Created in a laboratory via a series of chemical reactions between cyanuric chloride, isopropylamine, and others, atrazine quickly gained the love of farmers, industrial planners, and people in the lawn care industry. They all began using the chemical to kill broadleaf weeds and small grasses that tend to interfere with crops, domestic gardens, city mediums, and green spaces. (On a biochemical level, the atrazine inhibits the targeted plants' photosynthesis capabilities.) Atrazine also has the power to kill bacteria in swimming pools, which is why it was used as a main ingredient in chlorinating swimming pools.

The Switzerland-based pesticide company Syngenta is the leading manufacturer of atrazine and, of course, a massive promoter of its alleged pro-agricultural properties. Like many lab-made chemicals, manufacturers and scientists initially deemed atrazine "safe." It has no scent or color, and scientists back then didn't detect that it caused any harm to people or animals. (We must wonder, though: Did they even study its potential for harm back then?) Of course, Syngenta marketed the heck out of it to farmers seeking to grow their crop yields and yearly capital gain.

But as its use widened worldwide, mainly to increase the yields of corn, sugarcane, and sorghum, so did its presence in tap water, it leached into waterways, ponds, and other natural areas. As concentrations in water bodies grew, so did concerns—and fiery debates.

Heads Start Turning

Scientists, environmentalists, and activists began taking note of atrazine's consistent presence as it was washing into local ponds and water supplies. The chemical quickly became among the most common contaminants in drinking water sources, particularly in the US and various European countries.

The widespread presence of atrazine led to concern and curiosity, which thankfully resulted in testing, although this took more than a decade after atrazine's emergence. Findings about atrazine's potential harm to animal health began to catch people's attention. Researchers at the University of Sassari in Italy found atrazine to be potentially toxic to the nervous system. Another study found atrazine to disrupt normal immune system function in frogs. Meanwhile, other researchers deemed atrazine an "endocrine disruptor that demasculinizes and feminizes the gonads of male vertebrates."

The growing research findings caused people to take note and speak out. In 1994, the Environmental Protection Agency began expressing concerns about atrazine's effects and thus announced there would be scientific reviews of the chemical. Around the same time, the European Union dug deep and found its contaminated waterways to be a serious threat to the lives of humans, and thus officially banned the use of atrazine in 2003. The United States continued to take notice and implement exposure limits for the chemical, but atrazine remained both legal and in use.

An Iconoclast Proves the Harm

The proof that atrazine is downright bad for health is upsetting enough. But there's one story that adds to the impact: that of biologist Tyronne Hayes.

As more studies on atrazine’s potential harm were revealed, Syngenta, the leading manufacturer of atrazine, began fielding pressure to look closer at its product. To appear to be doing its due diligence, Syngenta hired Hayes to research the chemical and its impact on animal and human health. Hayes rolled up his sleeves and got to work, and he soon discovered something disturbing: atrazine appeared to be interfering with the sexual development of frogs. He researched this again. And again. His lines of evidence continued to show that atrazine disrupts the reproductive development of the frogs—and that it poses potential great risk to people. He brought this to Syngenta's and others in the field's attention—but Syngenta refused to acknowledge Hayes’s finding. In November of 2000, Hayes and Syngenta went their separate ways.

Here’s where it gets really weird. Later reports revealed that the behemoth company went to great lengths to harass Hayes, discredit his science, and tarnish his reputation as a lauded researcher. In a 2014 investigative article for The New Yorker, journalist Rachel Aviv outlines many of the attempts made by Syngenta, including how it claimed Hayes's studies could not be replicated, his work lacked statistical details, and his works weren't a clear relationship between the concentration of atrazine and the effect on the frog." Hayes also went on record to say that Syngenta followed him. A feature story in Mother Jones stated that the company paid for Google ads to divert any search results of Dr. Tyrone Hayes to "AgSense, an agribusiness coalition that leads its critique of Hayes by quoting his 'propriety and professionalism' outburst."

Through this wild, weird, and rather scary feud, Hayes stood by his research on the harms of atrazine, and many other scientists continue to today.

Atrazine Today

There is no denying that atrazine is scary and harmful. More than 40 countries see this and have officially banned its use. So why is it still allowed in the US? Regulators and those on the side of Syngenta argue that companies are allowed to only use the chemical under specific concentrations, which they posit are "safe." However, these concentrations still lead to runoff in the waterways. Plus, growing research continues to show that it's not only harmful to animals but to humans. Vanderbilt University Medical Center linked atrazine to a birth defect called gastroschisis. (In fact, a group of women in Kent, England, who all had children born with the same birth defect, believed atrazine to be the culprit.)

Thankfully, copious people are fighting back. In 2012, Syngenta settled for $105 million a lawsuit filed by more than 1,000 water providers in the Midwest who argued about the cost of removing atrazine from drinking water. Advocates in Hawaii have pushed to get the herbicide banned at the state level and have made promising strides. Companies continue to perfect filtering capabilities, including reverse osmosis and activated carbon, that rid the chemical from drinking water.

But still, atrazine is everywhere— in public water reserves, ponds, lakes, and more. It's critical to get informed on your city's levels. Contact your local municipal office to request a water report, stay educated, and take measures to filter your water and protect your health.