In 2010, Tyrone Hayes published a study in the Proceedings of the National Academy of Sciences that should have ended the career of the world’s most popular herbicide. Hayes, a biologist at UC Berkeley, had exposed genetically male African clawed frogs to atrazine at 2.5 parts per billion, a concentration well below the EPA’s legal limit for drinking water. The title of his paper was as blunt as a brick: “Atrazine induces complete feminization and chemical castration in male African clawed frogs.”
Complete feminization. Chemical castration. In a peer-reviewed paper published by the National Academy of Sciences.
The exposed males weren’t just demasculinized. Some of them became functional females. Genetically male frogs producing viable eggs, mating with unexposed males, producing offspring. The other exposed males showed severely reduced fertility, demasculinized larynges, and suppressed testosterone. About 10% appeared resistant to the effects. The rest were biologically wrecked by a chemical present in the drinking water of tens of millions of Americans.
Part 1 of this series established the data: sperm counts down 59.3% since 1973, testosterone declining ~1% per year, the trend accelerating after 2000. This article is about the chemicals doing it. Not in the abstract. Not as a category. The specific molecules, the specific mechanisms, and the specific companies that knew about the damage and fought to keep selling the products anyway.
The Plasticizer in Your Shampoo
Phthalates have been used since the 1930s in what the Natural Resources Defense Council describes as “an astonishing array of consumer products”: shower curtains, cosmetics, food containers, vinyl flooring, adhesives, medical devices, cleaning products, and fragrances. They make hard plastic flexible. They also make soft plastic cheaper. That’s why they’re in everything.
You can’t see them, smell them, or taste them. But they’re in your shampoo, your body lotion, your food packaging, your children’s toys, your vinyl flooring, and your IV tubes. They’ve been found in dairy products, meats, seafood, fruits, vegetables, and fast food. They leach from packaging during processing and delivery. And here’s the part that should make you angry: cosmetic companies aren’t legally required to disclose them. The FDA exempts manufacturers from listing individual fragrance or flavor components, letting phthalates hide on ingredient labels behind the single word “fragrance.”
What phthalates do inside the body is well understood. They’re anti-androgenic, meaning they suppress the hormones responsible for male development. The mechanism, documented across multiple peer-reviewed studies, works like this: phthalates are metabolized into monoesters, which suppress the genes that regulate steroidogenesis (testosterone production) in fetal Leydig cells. Less testosterone during the critical window of fetal development means altered male reproductive development. The results: reduced anogenital distance, smaller penis size, undescended testes, and lower sperm counts.
This isn’t speculation. Shanna Swan, the reproductive epidemiologist whose sperm count research we covered in Part 1, spent 20 years studying exactly this link. Her landmark 2005 study in Environmental Health Perspectives found that male infants born to mothers with higher phthalate exposure during pregnancy had shorter anogenital distance (AGD), a physical marker that directly tracks with testosterone levels during fetal development. Shorter AGD in adulthood is associated with smaller penis size and lower sperm count.
Animal studies had already established the pattern: mother rats given phthalates produced male offspring with smaller penises and scrotums, lower sperm counts, and shorter AGD. Swan proved the same “phthalate syndrome” exists in humans. As the New York Times summarized her findings: “For men, phthalates, found in many products, from plastics to shampoos, are the worst offenders, tanking testosterone levels and sperm counts.”
And the effects don’t stop with the exposed individual. The Endocrine Society, the world’s largest professional organization of hormone researchers, states: “Phthalate exposures are not only associated with reduced fertility but can affect fertility across multiple generations.”
Multiple generations. You are being exposed to a chemical that could damage your grandchildren’s reproductive systems before your children are even born.
The “BPA-Free” Lie
You’ve probably seen “BPA-free” labels on water bottles, food containers, and baby products. You may have assumed that meant the product was safe. That’s exactly what the manufacturers wanted you to assume. They were lying.
Bisphenol A (BPA) is the starting material for polycarbonate plastics and is used in the epoxy resins lining food and beverage cans. It mimics estrogen, binding to estrogen receptors and disrupting the body’s hormonal signaling. After decades of mounting evidence, the FDA finally banned BPA from baby bottles in 2012 and from infant formula packaging in 2013.
The replacement? Bisphenol S (BPS). Manufacturers claimed it was more resistant to leaching. If less of the chemical got out of the plastic, it would cause less harm. That was the sales pitch.
The reality: nearly 81% of Americans have detectable levels of BPS in their urine. It’s getting out. And once it enters the body, it behaves just like BPA.
In 2013, Cheryl Watson at the University of Texas Medical Branch at Galveston found that even picomolar concentrations of BPS (less than one part per trillion) can disrupt normal cell functioning, potentially leading to metabolic disorders, diabetes, obesity, asthma, birth defects, or cancer. Her assessment of the BPA-free label: “[Manufacturers] put ‘BPA-free’ on the label, which is true. The thing they neglected to tell you is that what they’ve substituted for BPA has not been tested for the same kinds of problems that BPA has been shown to cause. That’s a little bit sneaky.”
“A little bit sneaky,” is one way to describe a multibillion-dollar marketing campaign that charges you a premium for a product that’s equally toxic. There are more direct ways.
The evidence got worse. Deborah Kurrasch at the University of Calgary tested BPS on zebrafish embryos, because zebrafish brain development closely parallels human brain development. When exposed to BPS at concentrations found in nearby rivers, neuronal growth exploded: 170% increase for BPA, 240% increase for BPS. BPS was worse than the chemical it replaced. The fish became hyperactive. And Kurrasch found these effects at a dose 1,000 times lower than the daily recommended amount for humans.
At the University of Cincinnati, Hong-Sheng Wang found that both BPA and BPS cause heart arrhythmia in rats at concentrations matching those found in human blood.
In 2011, a study in Environmental Health Perspectives tested 455 commercially available plastic products and found that almost all of them leached estrogenic chemicals, including products marketed as BPA-free. George Bittner, a neurobiology professor at UT Austin who conducted the research, specifically tested Eastman Chemical Company’s product Tritan, which was marketed as completely free of estrogenic activity. His tests found it leached estrogens. Eastman Chemical’s response was not to reformulate. It was to sue him. A federal jury sided with Eastman, ruling that Bittner’s in vitro testing methods were inadequate.
That’s the system working as designed. A company sells a product labeled “safe.” An independent scientist proves it isn’t. The company sues the scientist. A jury full of people who don’t understand cell biology sides with the company. The product stays on the shelf.
And here’s the fact that ties the whole scam together: no federal agency tests the toxicity of new materials before they reach the market. Not the FDA. Not the EPA. Nobody. You are the test subject.
The Chemicals in Your Blood (That Will Outlive You)
Pick a random American. Draw their blood. There’s a 98% chance you’ll find PFAS in it.
Per- and polyfluoroalkyl substances, known as “forever chemicals,” are a class of roughly 12,000 synthetic compounds that have been manufactured since the 1940s. You know them from nonstick cookware (Teflon), waterproof clothing, stain-resistant carpets, food packaging, and firefighting foam. The carbon-fluorine bond that gives them their useful properties is one of the strongest in organic chemistry. That’s why they don’t break down. Not in the environment. Not in your body. Not ever, on any timescale that matters to humans.
PFOA (the compound used to make Teflon) has a half-life in the human body of 2 to 5 years. PFOS (used in Scotchgard and firefighting foam) has a half-life of 3 to 6 years. PFHxS, another common variant, 4.5 to 7 years. Those are half-lives, meaning you still have half the original amount after that period. And you’re being continuously re-exposed through food, water, and contact with treated products. The math is simple: intake exceeds elimination. The concentration in your blood keeps climbing.
A seven-year, 69,000-person health study called the C8 Science Panel, established as part of a legal settlement with DuPont, found a “probable link” between PFOA exposure and six diseases: kidney cancer, testicular cancer, ulcerative colitis, thyroid disease, pregnancy-induced hypertension, and high cholesterol. This wasn’t funded by environmental activists. DuPont agreed to fund the study as part of a class-action settlement after contaminating drinking water for roughly 70,000 people near its Washington Works plant in Parkersburg, West Virginia. They presumably expected the science panel to exonerate them. It didn’t.
But here’s what should make your blood boil (along with the PFAS already in it): the companies knew.
A 2023 analysis by UCSF researchers, published in the Annals of Global Health, examined internal industry documents and concluded that PFAS manufacturers had evidence of the chemicals’ toxicity and deliberately concealed it. Robert Bilott, the attorney whose decades-long battle against DuPont was dramatized in the film Dark Waters, uncovered internal company documents showing DuPont knew PFOA was harmful to health and continued production anyway.
3M, the other major PFAS manufacturer, ran the same playbook. Internal documents showed awareness of health risks going back decades. In 2022, after years of mounting lawsuits, 3M announced it would stop manufacturing PFAS by the end of 2025. Noble-sounding, until you remember they’d been making and selling these chemicals for over 70 years while sitting on evidence of harm.
3M settled with US public water suppliers for up to $12.5 billion. DuPont, Chemours, and Corteva added another $1.19 billion. That’s potentially $13.7 billion in total settlements. For chemicals that 3M and DuPont knew were dangerous. In your blood right now.
The Frog Guy They Tried to Destroy
Let’s go back to Tyrone Hayes and those frogs.
Hayes didn’t start as a crusader. He started as a contractor. In the late 1990s, Syngenta (then Novartis) hired him to study the effects of atrazine on amphibians. Atrazine is applied to more than half the corn grown in the United States. It’s one of the most widely used herbicides on the planet, and Syngenta, which sells over $14 billion per year in seeds and pesticides, needed studies showing it was safe.
Hayes found the opposite. His initial data showed atrazine impeding sexual development in frogs. In November 2000, he ended his relationship with Syngenta and continued the research independently. His 2002 PNAS paper showed hermaphroditic, demasculinized frogs at concentrations as low as 0.1 ppb, which is 30 times below the EPA’s legal limit for drinking water (3 ppb). His 2010 follow-up showed complete feminization and chemical castration at 2.5 ppb.
As Rachel Aviv detailed in a 2014 New Yorker investigation, Syngenta’s response was not to pull the product. It was to destroy Hayes.
Internal company documents, unsealed as part of a class-action lawsuit brought by 23 Midwestern cities, revealed that Syngenta’s PR team compiled a database of more than 130 “supportive third party stakeholders”, including 25 professors who could defend atrazine or act as “spokespeople on Hayes,” often for compensation. The company’s communications manager, Sherry Ford, wrote that Syngenta could “prevent citing of TH data by revealing him as noncredible.” Her notes characterized Hayes as someone who “grew up in a world (S.C.) that wouldn’t accept him,” “needs adulation,” “doesn’t sleep,” and was “scarred for life.”
The company’s PR team proposed purchasing “Tyrone Hayes” as a search term on the internet, “so that any time someone searches for Tyrone’s material, the first thing they see is our material.” The campaign was expanded to include “amphibian hayes,” “atrazine frogs,” and “frog feminization.” For years, Googling Tyrone Hayes’s name brought up a paid advertisement that read: “Tyrone Hayes Not Credible.”
A billion-dollar corporation buying a scientist’s name as a search keyword so they could personally discredit him in Google results. While continuing to sell the chemical that was feminizing amphibians at concentrations 30 times below legal limits.
And the EPA? It found “no risks of concern” from atrazine. The EU, working with the same data, banned it in 2004.
The Poison Is the Dose (They Got It Backwards)
There’s a phrase toxicologists have used since the 16th century: “the dose makes the poison.” The idea is intuitive. More of a substance causes more harm. Less causes less harm. Below some threshold, the amount is too small to matter.
For endocrine disruptors, this model is wrong. Not partially wrong. Fundamentally, structurally wrong.
In 2012, Laura Vandenberg and a team of researchers published a landmark review in Endocrine Reviews evaluating more than 800 scientific papers on the effects of hormones and endocrine-disrupting chemicals. Their conclusions were direct: “most if not all [EDCs] are likely to have low-dose effects” and “when nonmonotonic dose-response curves occur, the effects of low doses cannot be predicted by the effects observed at high doses.”
A nonmonotonic dose-response curve means the relationship between dose and effect isn’t a straight line. It’s a U-shape, or an inverted U. At very low doses, you get a strong effect. At moderate doses, the effect diminishes. At high doses, it returns. The pattern makes no sense under the “dose makes the poison” framework. It makes perfect sense once you understand how hormones work.
Your endocrine system operates on concentrations measured in parts per trillion. Estrogen in a woman’s blood fluctuates from about 30 picograms per milliliter to 800 during ovulation. The difference between “normal” and “ovulating” is measured in billionths of a gram. The system is designed to respond to vanishingly small signals. Endocrine disruptors exploit this same machinery. They don’t need industrial-accident concentrations to cause effects. They need exactly the kind of concentrations you’d find in drinking water, food packaging, and thermal receipt paper.
As Deborah Kurrasch explained after finding that BPS damaged zebrafish brain development at concentrations 1,000 times below the recommended daily amount: “Part of the problem with endocrine disruptors is they usually have a U-shaped dose response profile. At very low doses they have activity and then as you increase the dose it drops in activity. Then at higher doses it has activity again.”
This isn’t an academic distinction. It’s the reason the entire US regulatory framework for chemical safety is broken at the foundation. The EPA sets “safe” exposure limits by testing chemicals at high doses, identifying the dose that causes harm, and then dividing by a safety factor to establish a threshold. If the dose-response curve is linear, this approach works. If the curve is U-shaped, the “safe” level might fall exactly in the range where the chemical is most biologically active.
Hayes found atrazine feminizing frogs at 0.1 ppb. The EPA says 3 ppb is safe. Watson found BPS disrupting cells at less than one part per trillion. The regulatory system didn’t account for any of this, because the regulatory system was built on a 500-year-old assumption that doesn’t apply to the chemicals it’s supposed to be regulating.
The System Isn’t Broken. It Was Built This Way.
If you’re wondering how chemicals that feminize frogs, suppress testosterone, cause cancer, and persist in human blood for years are still legal, the answer isn’t that regulators missed the science. The answer is that the system was designed by the people selling the chemicals.
Under the Toxic Substances Control Act (TSCA), the foundational US chemical safety law passed in 1976, approximately 62,000 existing chemicals were grandfathered in without requiring any safety testing. In the 40 years before TSCA was reformed in 2016, the EPA successfully restricted exactly five chemicals using its Section 6 authority: PCBs, chlorofluorocarbons, dioxin, asbestos, and hexavalent chromium. Five. Out of tens of thousands. And courts partially overturned even the asbestos ban after manufacturers argued it would hurt the economy.
The European Union operates differently. Under REACH and the EU Cosmetics Regulation, manufacturers must prove their chemicals are safe before selling them. The result: the EU has banned or restricted over 1,300 chemicals from cosmetics. The FDA has banned 11. Some counts put the EU number above 1,600. The US number wouldn’t fill a Post-it note.
The EU banned atrazine in 2004. It’s still sprayed on half the corn in America. The EU restricts phthalates in consumer products. The US lets them hide behind the word “fragrance.” The EU set drinking water limits for PFAS at 0.1 micrograms per liter. For decades, the US had no enforceable federal limit at all.
The gap between US and EU chemical regulation isn’t an accident or a difference in scientific interpretation. It’s the difference between a system designed around the precautionary principle (prove it’s safe before you sell it) and a system designed around industry convenience (sell it until someone proves it’s dangerous, then make them fight you in court for 30 years). The American chemical industry spent decades and hundreds of millions of dollars building the second system. It works beautifully. For them.
But don’t mistake Europe for a solution. The EU’s chemical bans look impressive on paper. In practice, European store shelves are still dominated by fragranced products, and finding genuinely clean alternatives can be harder than in the US, where consumer demand has built an entire clean-product market that barely exists in Europe. Regulatory capture operates on both continents. It just wears different clothes. The EU’s precautionary principle didn’t stop member states from approving glyphosate repeatedly. It didn’t stop PFAS from contaminating European water supplies.
And the bureaucratic cost of REACH compliance crushes small manufacturers while barely inconveniencing the chemical giants who can afford the paperwork.
The real lesson isn’t “we need better regulators.” It’s that waiting for any government to protect you is the slowest and least reliable path to safety. The companies that poisoned your water spent more on lobbying than your local EPA office spends on everything. The families who actually reduced their chemical exposure did it themselves: reading labels, switching products, voting with their wallets. The market for clean products exists because consumers built it, not because a regulator mandated it.
The Playbook
If the chemical industry’s tactics sound familiar, they should. They’re the same ones the tobacco industry used for 50 years.
Fund competing studies to manufacture doubt. Syngenta maintained a database of 130 third-party stakeholders who could publicly defend atrazine. Twenty-five were professors. The company funds research at approximately 400 academic institutions. When you fund the research, you influence what gets studied, what gets published, and what gets buried.
Attack the researchers, not the research. Syngenta didn’t publish a study disproving Hayes’s findings. They bought his name as a Google keyword and ran ads calling him not credible. They compiled dossiers on his personality. They explored ways to “exploit his faults/problems.” They considered having third-party scientists file complaints against him at his university. They basically operate like the mob.
Sue scientists who publish inconvenient findings. Eastman Chemical didn’t reformulate when George Bittner found their “BPA-free” plastic leached estrogens. They took him to court.
Conceal internal evidence of harm. 3M and DuPont both had internal documents showing PFAS were toxic. They concealed the evidence for decades. The cost, when they finally got caught: $11.5 billion in settlements. For companies with annual revenues in the tens of billions, that’s just the cost of doing business.
When forced to change, switch to a slightly different chemical and start over. BPA gets banned from baby bottles. BPS takes its place. BPS turns out to be equally harmful (or worse). Nobody tests the replacement before it goes to market. 3M stops making a few PFAS compounds. Roughly 12,000 others remain in use. The cycle continues.
This is not a failure of the system. This is the system. Tobacco companies spent decades selling a product they knew caused cancer while funding fake science to create doubt. Chemical companies are doing the same thing with products that suppress testosterone, mimic estrogen, and persist in your blood for years. The difference is that cigarettes were optional. Phthalates are in your shampoo. BPS is in your receipt paper. PFAS is in your blood. Atrazine is in your water. You didn’t choose any of this. You were never asked.
What You Can Do Now
The situation is bad. But it’s not hopeless. Chemical exposure is largely a function of choices, and many of the most impactful changes are straightforward.
Purge plastic from your kitchen. Replace plastic food storage with glass or stainless steel. This is the single highest-leverage swap. Never microwave food in plastic. Never store hot food in plastic. Heat accelerates leaching. If you do one thing after reading this article, stop eating food that touched hot plastic.
Filter your water. A quality activated carbon filter removes atrazine, and many filters now specify PFAS removal. Reverse osmosis removes essentially everything. Your tap water is a daily exposure vector for multiple endocrine disruptors, and a filter costs less than a month of takeout.
Ditch nonstick cookware. Teflon is a PFAS product. Switch to cast iron, stainless steel, or ceramic. Cast iron is cheaper than nonstick and lasts generations. It’s what we’ve been using for years.
Read labels like your fertility depends on it (because it does). The word “fragrance” on a personal care product is a legal hiding place for phthalates. Choose products labeled “phthalate-free” or “fragrance-free” (not “unscented,” which can still contain masking fragrances). The Environmental Working Group maintains databases rating thousands of products by chemical content. Use them.
Avoid thermal receipt paper. Those store receipts are coated in BPA or BPS. Research shows up to 25% dermal absorption over 24 hours. Decline paper receipts when possible. If you handle them regularly for work, consider gloves.
Skip fast food and heavily packaged food. People who eat more fast food have higher phthalate exposure. The packaging is the problem. Food that comes in cardboard, plastic wrap, and paper containers has been marinating in endocrine disruptors.
Buy organic where it matters. Atrazine is used on conventionally grown corn. Organic certification prohibits it. The “Dirty Dozen” list identifies the produce with the highest pesticide residue. Start there.
Cook from whole ingredients. Every step of industrial food processing adds contact with plastic equipment, packaging, and chemical treatments. The fewer intermediaries between the food and your mouth, the less chemical exposure.
Think about your children’s exposure starting before conception. Swan’s research shows that phthalate exposure during pregnancy affects fetal development. The Endocrine Society warns of multigenerational effects. If you’re planning to start a family, reducing chemical exposure isn’t just about your health. It’s about your future children’s reproductive capacity.
These changes aren’t exotic. They’re what your grandparents did by default: cook real food, store it in glass, drink clean water, avoid unnecessary chemicals. The difference is that your grandparents didn’t need to actively opt out of a chemical environment that didn’t exist yet. You do. That’s the cost of living in a civilization that let chemical companies write their own safety regulations for 50 years.
The next article in this series, “The Biosludge Problem,” covers another vector you probably haven’t considered: treated sewage being spread on farmland as “biosolids,” carrying pharmaceuticals, heavy metals, and microplastics directly into the food chain. With the EPA’s blessing.
Sources
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Great work. Informative and motivating. A fear of mine is that as we become more aware of the need to opt out of this default (chemicals, screens, etc), those that wish to be be parents near term have a growing barrier of axiety around raising a child in a world where our default condition is inherently anti-life.