Silencing the Scientist: The Story of Dr. Tyrone Hayes and the Atrazine Cover-Up

When Corporate Power Attacks Science

In 1997, Dr. Tyrone Hayes, a promising young endocrinologist at UC Berkeley, was hired by Syngenta (then Novartis) to study the effects of atrazine – one of the most widely used herbicides in America. What Hayes discovered would trigger a 20-year campaign of intimidation, discreditation, and corporate suppression. This is what happens when a scientist discovers something a billion-dollar corporation doesn’t want the world to know.

Hayes found that atrazine, applied to more than half the corn crops in the United States, causes sexual abnormalities in frogs at ecologically relevant doses. Male frogs exposed to atrazine develop female reproductive organs. Some become complete females. Others become hermaphrodites with both testes and ovaries. When Syngenta saw these results, they didn’t celebrate the discovery. They tried to bury it.

The Discovery

Hayes’ initial findings were stunning. Genetic male frogs exposed to atrazine showed:

• Reduced larynx development (indicating low testosterone)
• Decreased fertility
• Development of ovaries and eggs in genetically male frogs
• Complete sex reversal in some cases
• Homosexual behavior in exposed males

The doses that caused these effects were not extreme laboratory levels. They were ecologically relevant—the kinds of concentrations found in real-world environments and drinking water.

When Hayes first shared these findings with Syngenta, the company’s response was telling. They didn’t engage in scientific debate. They didn’t ask for more research. They asked him to manipulate the data.

The Corporate Campaign Against Science

What happened next is documented in court records from a class-action lawsuit against Syngenta. Internal company memos—written notes that executives never expected to see the light of day—reveal a deliberate, systematic campaign to destroy Dr. Hayes’ credibility and suppress his research.

Syngenta’s goals, as stated in their own documents:

• Discredit Hayes – Make him appear non-credible and unreliable
• Exploit his vulnerabilities – Investigate his personal life, his family, his background
• Control the narrative – Hire scientists to produce contradictory studies
• Silence him – Threaten him, follow him, intimidate him

According to court documents, Syngenta executives discussed:

• Investigating Hayes’ wife
• Exploiting his father’s health problems
• Setting traps to entice him to sue (making him look litigious)
• Hiring a detective agency to follow him
• Having company representatives attend his lectures to intimidate him
• Making threats of violence

One executive wrote that if Hayes “were involved in a scandal the enviros will drop him.”

Hayes received threats that crossed every line. Company officials whispered to him that they could have him “lynched.” They threatened his wife and daughter with violence. They told him they had access to his email and knew where he was at all times.

The EPA Becomes Complicit

Perhaps most troubling is what happened at the Environmental Protection Agency. The EPA was supposed to be the independent arbiter of atrazine’s safety. Instead, documents show the EPA collaborated with Syngenta to design studies in ways that would exclude Hayes’ research.

Here’s what the EPA did:

• Created impossible standards – The EPA and Syngenta together designed “Good Laboratory Practice” protocols so expensive and complex that no independent academic laboratory could afford to replicate them.
• Discarded independent research – Every study in the open scientific literature that didn’t follow these protocols was declared “qualitative” and thrown out. That’s 36 studies—gone.
• Accepted only industry studies – By 2007, only one study remained that met the EPA’s criteria for a regulatory decision. That study? Funded by Syngenta.
• Reached a predetermined conclusion – Based on this single industry-funded study, the EPA concluded that atrazine poses no risk to frogs. No additional testing needed.

The EPA’s scientific advisory panel disagreed. They recommended multiple species be tested. They recommended a weight-of-evidence approach. The EPA ignored them.

Read about SAVE THE FROGS! Dr. Kerry Kriger’s 2011 visit to the EPA headquarters here.

Watch SAVE THE FROGS! Dr. Kerry Kriger’s 2012 speech at the EPA headquarters here.

The Broader Picture: Corporate Power Over Science

The story of Dr. Tyrone Hayes is not unique. It’s a template. This is how the product defense industry works:

• A scientist publishes research showing a product is harmful
• The manufacturer manufactures doubt by funding contradictory studies
• The manufacturer hires PR firms and paid scientists to create the appearance of controversy
• Regulatory agencies, captured by industry influence, use that manufactured doubt as justification for inaction
• The public remains confused. The product stays on the market. People are harmed.

We’ve seen this with tobacco, asbestos, lead, atrazine and countless other chemicals.

What We Know About Atrazine

Despite Syngenta’s efforts, the scientific evidence is overwhelming:

In Frogs:

• Multiple independent studies show atrazine causes feminization and hermaphroditism
• Effects occur at environmentally relevant doses (0.1 parts per billion)
• The phenomenon has been observed across multiple frog species worldwide

In Other Animals:

• Atrazine causes sexual abnormalities in fish, birds, reptiles, and mammals
• Effects persist across multiple generations
• The impact on reproduction and development is consistent across species

In Humans:

• Atrazine is associated with increased prostate cancer in men exposed occupationally (8.4-fold increase)
• Studies show correlation with breast cancer
• Multiple studies link atrazine exposure to birth defects
• Atrazine is associated with low sperm count and reduced testosterone

In the Environment:

• 33 million Americans have been exposed to atrazine through drinking water
• It was banned in the European Union in 2003
• It remains on the market in the United States

Watch Dr. Tyrone Hayes’ Presentation to SAVE THE FROGS! Academy Students

SAVE THE FROGS! Founder Dr. Kerry Kriger and UC Berkeley Professor Dr. Tyrone Hayes give presentations on the harmful pesticide Atrazine and discuss ways that you can help get it banned. Recorded August 18th, 2013.

Why This Matters for SAVE THE FROGS!

The story of Dr. Tyrone Hayes is the story of what happens when democracy fails to protect the environment. It’s what happens when corporate power overwhelms public interest. It’s what happens when regulatory agencies are captured by industry.

This is exactly why SAVE THE FROGS! connects environmental protection with democracy protection. You cannot have strong environmental protections without:

• Independent scientists who can speak freely
• Regulatory agencies that aren’t captured by industry
• Democratic institutions that prioritize public health over corporate profit
• Legal systems that hold corporations accountable for suppressing scientific evidence

Frogs are disappearing. But they’re not disappearing because scientists don’t know why. They’re disappearing despite what scientists have discovered. And unfortunately, certain corporations are trying to silence the scientists working to protect human and environmental health.

Watch the Story

To learn more about Dr. Tyrone Hayes and his fight for scientific integrity, watch these three documentaries:

Silencing the Scientist: Tyrone Hayes on Being Targeted By Herbicide Firm Syngenta

This is Democracy Now’s coverage of Dr. Hayes’ story, featuring an interview with Hayes himself discussing how Syngenta targeted him, threatened him, and tried to suppress his work.

Interview with Scientist Dr. Tyrone Hayes

A deeper dive into Hayes’ research and methodology, where he explains exactly what his studies showed and how he conducted his science with rigorous objectivity despite the pressure from Syngenta.

Gay Frogs: A Deep Dive

A comprehensive examination of the atrazine story, tracing how Syngenta manipulated the EPA’s regulatory process, how they paid third-party scientists to discredit Hayes, and how corporate power corrupted what should have been an independent scientific and regulatory process, all inspired by Alex Jones’ famous rant about “Gay Frogs”.

What You Can Do

Support Independent Science

• Donate to organizations like SAVE THE FROGS! that work to support and protect science, scientists and the environment.

Demand Democratic Accountability

• Support efforts to reform regulatory agencies so they can’t be captured by industry
• Vote for candidates who prioritize environmental protection and scientific integrity
• Contact your representatives and demand stronger environmental protections

Speak Up

• Share this story. Tell people about Dr. Tyrone Hayes. Tell them about atrazine.
• Challenge the narrative that there’s “controversy” around atrazine. There isn’t. Scientists agree.
• Recognize that when you hear manufactured doubt, it may be because a corporation is trying to protecting its profits.

Defend Science

• Support scientists who are willing to speak truth to power
• Recognize that scientific integrity is under attack—and that’s a threat to all of us
• Understand that defending science is critical in the 21st century.

The Bottom Line

Dr. Tyrone Hayes discovered something important. He did rigorous science. He published in top journals. He spoke the truth. And for that, a billion-dollar corporation tried to destroy him.

We understand something fundamental: you cannot have a healthy environment without a healthy democracy, and you cannot have a healthy democracy without protecting science.

Frogs are disappearing. We know why. We know what’s killing them. The question is: will we do anything about it?

Or will we let corporate power keep silencing the scientists trying to save them?

Let’s defend democracy and the environment together, because they’re inseparable…learn about the Million Frog March here and take action.

Learn More

• Read the New Yorker article: “A Valuable Reputation”
• Learn more about atrazine from SAVE THE FROGS!

Together, we will not be silenced—and neither will the frogs. 🐸