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A young child frolics in a fountain in Portland, Ore., on July 31, 2015. (AP) A young child frolics in a fountain in Portland, Ore., on July 31, 2015. (AP)

A young child frolics in a fountain in Portland, Ore., on July 31, 2015. (AP)

Grace Abels
By Grace Abels June 28, 2023
Luiz Romero
By Luiz Romero June 28, 2023
Jill Terreri Ramos
By Jill Terreri Ramos June 28, 2023

No evidence atrazine in the water supply is causing more kids to identify as transgender

If Your Time is short

  • Atrazine is a commonly used herbicide in the U.S. The Environmental Protection Agency regulates how much is allowed in drinking water and evaluates potential ecological and human health risks. 

  • No scientific studies in humans have linked atrazine exposure to gender dysphoria. It has been linked, in some studies, to birth defects and other reproductive health problems.

  • Robert F. Kennedy Jr.’s claim appears to be based on a 2010 University of California, Berkeley study that found that when male frogs were exposed to atrazine, some lost fertility and developed ovaries. Differences in human and frog biology mean these findings do not unilaterally extend to humans.

Are herbicides in the water causing children to become transgender? 

That was the theory Democratic presidential challenger Robert F. Kennedy Jr. posed on a June 5 podcast.  

"I think a lot of the problems we see in kids, and particularly boys, it's probably underappreciated how much of that is coming from chemical exposures, including a lot of the sexual dysphoria that we’re seeing," said Kennedy to podcast host and conservative commentator Jordan Peterson. 

The podcast episode was taken down from YouTube for sharing misinformation about vaccines, but clips continue to spread on Twitter and TikTok. 

TikTok identified video from the podcast as part of its efforts to counter inauthentic, misleading or false content. (Read more about PolitiFact’s partnership with TikTok.)

"Sexual dysphoria" is not a medical term, according to experts, and Kennedy’s team did not respond to a request to clarify his meaning of that phrase. Gender dysphoria is the experience of distress that can occur when a person’s gender identity does not match their sex assigned at birth, and is common in transgender people. 

In the podcast, Kennedy referred to a study that found that exposure to the herbicide atrazine in water caused some male frogs to develop female sex organs and become infertile. His description matches the details of a study published in 2010

"If it’s doing that to frogs, there’s a lot of other evidence that it’s doing it to human beings as well," Kennedy said. He offered no examples of that evidence. Kennedy made similar comments on Joe Rogan’s podcast 10 days later.

But, with apologies to Kermit the Frog, there are some important biological differences between humans and frogs, and although atrazine may pose some human health risks, there is no evidence that atrazine exposure is linked to gender dysphoria in humans. 

@politifact There's no evidence for Democratic presidential candidate Robert F. Kennedy Jr.'s claim that the herbicide atrazine in water is contributing to youth experiencing what he called “sexual dysphoria.” We rated his claim False. #atraztine #genderdysphoria #rfkjr #factcheck #fyp #learnontiktok ♬ Astro Beat - Staysee

Kennedy’s team did not respond to requests for comment. 

What is atrazine? 

According to the U.S. Department of Agriculture, atrazine is one of the nation’s most commonly used herbicides. Atrazine, first registered for use in 1958, works by inhibiting photosynthesis on broadleaf plants and grasses. It is used mostly in large-scale agriculture by people who are government-certified in how to apply restricted-use pesticides.

Atrazine enters drinking water through agricultural runoff from row crops, the Environmental Protection Agency said. Row crops are annual food and fiber plants such as corn, soybeans, rice and cotton. 

Under the Safe Drinking Water Act, the EPA regulates atrazine levels in drinking water. The legal limit is 0.003 milligrams/liter, or 3 parts per billion.

The EPA’s 2018 human health risk assessment of atrazine "found no risks of concern when evaluating all dietary exposure sources including drinking water." The agency identifies potential risks for children playing on lawns treated with the chemical, and occupational exposure to the herbicide. 

But not everyone agrees with EPA’s assessment. Use of the chemical is banned in the European Union and many groups that advocate for biological diversity and food safety have opposed its use. The Federal Insecticide, Fungicide and Rodenticide Act requires the EPA to periodically reevaluate pesticides to stay up to date with the most recent science. In 2020, atrazine was re-approved with updated risk mitigation measures. 

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The decision prompted legal action from several organizations who felt the EPA made its decision without "substantial evidence."  The EPA was allowed to reevaluate part of its decision and has proposed new risk mitigation efforts. After public comment, regulations on atrazine are expected to be finalized

Concerns about atrazine center on its potential to disrupt hormones in the body. Atrazine exposure in humans has been linked to reproductive health issues including birth defects, and low birth weight. There is also research that suggests a link to kidney disease, wheezing, and higher body mass index in farmers who use the herbicide. 

Although atrazine may pose health risks, no studies in humans have shown a link between atrazine exposure and gender identity or sexual orientation. 

Atrazine and frogs 

In his podcast discussion with Peterson, Kennedy described the same findings as a 2010 study from the University of California, Berkeley. 

"If you, in a lab, put atrazine in a tank full of frogs, it will chemically castrate and forcibly feminize every frog in there," Kennedy said. "And 10% of the male frogs will turn into fully viable females able to produce viable eggs." 

Kennedy’s description of the study was mostly accurate, and when it was first published, the study garnered quite a lot of attention. Its lead researcher, Tyrone B. Hayes, was profiled in The New Yorker. Reaction to the study also spawned a viral meme of right-wing Infowars podcaster Alex Jones shouting, "I don't like 'em putting chemicals in the water that turn the freaking frogs gay!"

To learn more, PolitiFact talked with Hayes, a professor at University of California, Berkeley’s Department of Integrative Biology.

He said he supports more research into atrazine’s health effects on animals and humans but said of Kennedy’s claim, "There are no data to really make that link. That's speculation." 

He also explained key differences between humans and their amphibian friends. Both amphibians and fish, "have relatively permeable skin," Hayes said. "So, at a lower dose, they might absorb the compound more." Most people are mostly exposed to atrazine through drinking water, Hayes said. Exposure through the skin and lungs is more common in industrial applications. 

When exposed to atrazine, humans are also more easily able to filter it out through urine. Frogs live in the water they urinate in and so are less able to escape long-term exposure.

Hayes also said that amphibians, along with fish and some reptiles, have more sexual fluidity. 

"You can have a genetically male frog and give it estrogen and it'll grow an ovary," Hayes said. The same doesn’t apply to humans.

Hayes pointed to several studies of atrazine in mammals such as rats and mice that raise concerns about lowered testosterone and genital abnormalities. Although low levels of testosterone can cause health problems, like reduced sex drive, fatigue, increased body fat, and depression, it has not been associated with gender dysphoria or being transgender, experts said.

Experts still don’t know why some people are transgender, or why more young people are identifying as transgender or gender-nonconforming. 

"There are no data that trans people prior to treatment have different hormone levels" than people who are not trans, said Dr. Joshua Safer, an endocrinologist and the executive director of the Mount Sinai Center for Transgender Medicine and Surgery.

Our ruling 

Kennedy said the herbicide atrazine in the water supply is contributing to "sexual dysphoria" in children. 

"Sexual dysphoria" is not a medical term and Kennedy’s team did not respond when we asked for clarification of that phrase. Gender dysphoria is the experience of distress that can occur when a person’s gender identity does not match their sex assigned at birth.

Some research suggests atrazine can harm human health, specifically related to reproductive health and hormones. But no scientific studies in humans link atrazine exposure to gender dysphoria. 

A 2010 study in frogs that Kennedy appeared to refer to found evidence that atrazine exposure has a feminizing effect on frogs and can cause genetically male frogs to develop ovaries. But biological differences mean those findings cannot be unilaterally applied to humans. The frog study’s lead researcher said there is currently no data to support Kennedy’s claim. 

We rate this claim False.

Our Sources

Interview with Tyrone B. Hayes, Professor at University of California, Berkeley’s Department of Integrative Biology, June 23, 2023

Email Interview with Dr. Joshua Safer, Executive Director of the Mount Sinai Center for Transgender Medicine and Surgery, June 27, 2023

Email Interview with Mikko Väänänen, Press Officer at the European Chemicals Agency, June 27, 2023

Email Interview with Dr. Alex Keuroghlian, Director of the Massachusetts General Hospital Psychiatry Gender Identity Program, June 27, 2023

Email Interview with Dr. Michelle Forcier, a Folx Clinician and professor of pediatrics at the Alpert School of Medicine at Brown University, June 26, 2023

Jordan B. Peterson Podcast, "Rekindling the Spirit of the Classic Democrat | Robert F. Kennedy Jr.," June 5, 2023

NBC News, "YouTube removes video of Robert F. Kennedy Jr. and Jordan Peterson for vaccine misinformation," June 19, 2023

Tweet, June 18, 2023

PolitiFact, "‘Gender dysphoria’: What it is, what it isn’t and how history has changed its view," May 22, 2023

PNAS, "Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis)," March 9, 2010

U.S. Environmental Protection Agency, "Herbicides," March 2, 2023

National Pesticide Information Center, "Atrazine Fact Sheet," Feb. 14, 2020

U.S. Environmental Protection Agency, "How to Get Certified as a Pesticide Applicator," Feb. 27, 2023

U.S. Environmental Protection Agency, "Safe Drinking Water Act (SDWA)," March 30, 2023

U.S. Environmental Protection Agency, "Drinking Water Regulations," Sept. 20, 2022

U.S. Environmental Protection Agency, "Atrazine. Draft Human Health Risk Assessment for Registration Review," July 26, 2018

U.S. Environmental Protection Agency, "Atrazine," June 20, 2023

The New York Times, "A Pesticide Banned, or Not, Underscores Trans-Atlantic Trade Sensitivities," Feb. 23, 2015
Pesticide Action Network, "Atrazine: Science under siege," accessed June 27, 2023

Center for Biological Diversity, "The Case for Banning Atrazine," accessed June 26, 2023

Center for Food Safety, "Atrazine," accessed June 26, 2023

Center for Food Safety, "Petition for Review," Oct. 30, 2020

Center for Biological Diversity, "Lawsuit Challenges EPA Reapproval of Endocrine-disrupting Pesticide Atrazine," Oct. 30, 2020

Toxics, "Atrazine exposure and reproductive dysfunction through the hypothalamus-pituitary-gonadal (HPG) axis," December 2015

Birth Defects Research Part B: Developmental and Reproductive Toxicology, "Atrazine and pregnancy outcomes: a systematic review of epidemiologic evidence," May 2, 2014

Centers for Disease Control and Prevention, "Atrazine | Public Health Statement | ATSDR," Nov. 28, 2011

Environmental Health Perspectives, "Urinary biomarkers of prenatal atrazine exposure and adverse birth outcomes in the PELAGIE birth cohort," July 2011

American Journal of Medical Genetics, "Case-control study of maternal residential atrazine exposure and male genital malformations," May 2013

International Journal of Environmental Research and Public Health, "Atrazine contamination of drinking water and adverse birth outcomes in community water systems with elevated atrazine in Ohio," August 2018

Occupational and Environmental Medicine, "Pesticide use and risk of end-stage renal disease among licensed pesticide applicators in the Agricultural Health Study," January 2016

Environmental Health Perspectives, "Pesticides are Associated with Allergic and Non-Allergic Wheeze among Male Farmers," April 1, 2017

Journal of Toxicology and Environmental Health, "Pesticide exposures and body mass index (BMI) of pesticide applicators from the agricultural health study," Oct. 19, 2015

National Geographic, "Common weed killer makes male frogs lay eggs," March 2, 2010

Reuters, "Common weedkiller turns male frogs into females," March 1, 2010

Scientific American, "A common herbicide turns some male frogs into females," March 2, 2010

CNN, "Weed killer 'castrates' male frogs, study says," March 1, 2010

The New Yorker, "A Valuable Reputation," Feb. 2, 2014

YouTube, "Gay Frogs (Alex Jones REMIX)," June 22, 2017

HowStuffWorks, "Alex Jones and InfoWars: Fact or Tinfoil Fiction?" June 8, 2018

Healthline, "Is Low Testosterone Dangerous to Your Health?" March 31, 2017

Pew Research Center, "About 5% of young adults in U.S. are transgender or nonbinary," June 7, 2022

Journal of Developmental Origins of Health and Disease," Atrazine induces penis abnormalities including hypospadias in mice," June 2020

Environmental Science and Pollution Research, "Meta-analysis and experimental validation identified atrazine as a toxicant in the male reproductive system," July 2021

The Joe Rogan Experience, "#1999 - Robert Kennedy, Jr." June 15, 2023

 Cleveland Clinic, "Low Testosterone (Low T): Causes, Symptoms & Treatment," Sept. 2, 2022

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No evidence atrazine in the water supply is causing more kids to identify as transgender

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