For decades, it was the secret behind the magic show of homemaking across America. Applied to a pan, it could keep a fried egg from sticking to the surface. Soaked into a carpet, it could shrug off spills of red wine. Sprayed onto shoes and coats, it could keep the kids dry on a rainy day.

But the most clandestine maneuver of perfluorooctanoic acid, or PFOA, was much less endearing: seeping into the blood and organs of hundreds of millions of people exposed to the chemical.

Most people who’ve heard of the chemical likely know about it because it was found to be toxic and removed from consumer goods in 2015 after decades of use, leading to modern boasts of “PFOA-free” on product packaging. In recent years, PFOA — one of a broader swath of “forever chemicals” typically referred to as PFAS — has also become the target of widespread regulatory action, news media attention and even a Hollywood movie as contaminated drinking water was discovered in hundreds of communities across the United States.

While most concerns about the chemical’s health risks have centered on communities where research has linked PFOA to cancer and other serious illnesses, public health researchers say it serves as a klaxon of something more insidious.

PFOA is just one of dozens of modern chemicals found in the bodies of the majority of Americans, regardless of where they live. Research has also shown that more Americans are facing a growing number of ailments and disorders, from autoimmune disease to developmental disorders such as autism and some cancers. Scientists are increasingly concerned these two truths are linked, and some believe that the American public and lawmakers alike are dangerously unaware of the perils lurking in their veins. 

“It’s very hard for people to understand exposure and effects when they can’t see a smoking gun,” said Linda Birnbaum, a former director of the National Institute for Environmental Health Sciences.

Sorting out the causes of troubling public health trends is difficult. For example, how much is due to aging demographics, personal behaviors, diagnostic changes or environmental exposures? But in recent years, scientists have accumulated enough data to conclude with confidence that humans face significant health risks from exposure to common commercial chemicals, and that regulations designed to protect them are failing.

“I do think this area has been badly overridden by industry,” said Wendy Wagner, an attorney and professor at the University of Texas at Austin School of Law who has written about chemical contaminants. “People don’t realize that we actually encourage and even subsidize the production of tens of thousands of chemicals, while imposing essentially no requirements on manufacturers to test their safety. Nor do we ask whether we need the chemical, whether it’s useful, whether there are safer substitutes – or what it’s doing to the environment.”

When to declare a chemical safe or unsafe is critical. Experts say that due to flaws in federal regulation, the U.S. Environmental Protection Agency (EPA) is perennially playing catch up. The majority of the 86,000 consumer chemicals registered with the agency have never received rigorous toxicity testing. 

The EPA doesn't dispute that potentially dangerous chemicals have entered the market, but told The Examination that “far fewer” than 86,000 chemicals are still used today. The agency further stated that it believes it has made “significant progress” in addressing the risks of chemicals over the past four decades and in recent years has worked to draft a bevy of new rules and actions to address remaining high-priority risks.

“Where we identify unreasonable risks from a chemical, we must take action to address [them],” the agency wrote in email. “These proposed rules are great examples of protective actions that have prompted strong engagement from industry and environmental [nonprofit] stakeholders, but we made them by following the law and the science to protect human health.”

The American Chemistry Council (ACC), a trade group for the chemical industry, also pushed back on the notion that commercial chemicals are under-tested.

“It’s a common misperception that chemicals in commerce are lacking relevant or important toxicology data. Most major commercial chemistries have extensive physical/chemical and toxicological information available," the ACC said in response to a request for comment from The Examination, adding that, "Chemicals in commerce are subject to stringent government oversight.”

But PFOA is an example of how a chemical can slip through the cracks and cause damage even when its dangers are eventually identified.

A phaseout of that chemical in consumer products began in the early 2000s and concluded in 2015, but it remains in the bodies of more than 9 in 10 Americans today, its impacts still unfolding.

Tracey Woodruff, director of the Program on Reproductive Health and the Environment at the University of California, San Francisco, said the dangers of PFOA exposure are real, if difficult to appreciate. A study she helped lead, published in 2014 in the journal Environmental Health Perspectives, calculated a relationship between decreased birth weight and PFOA.

Woodruff’s team estimated the average woman in the U.S. had enough PFOA in her body to account for roughly an ounce decrease in the birth weight of her offspring. While that may not sound like much, additional calculations showed that if the most highly exposed women could reduce their PFOA levels closer to the mean, as many as 40,000 low-weight births could be avoided each year.

“What we have learned is that even small amounts of these chemicals have an impact on fetal development, including increasing risk of infant death and other public health implications,” said Woodruff, who is on the advisory council of The Examination.

But the dangers of chemical exposure go far beyond PFOA. 

Preemies in intensive care units appear to have higher amounts of plastics chemicals called phthalates in their bodies, likely from exposure to breathing equipment, according to a 2020 paper authored by Chris Gennings, director of the Division of Biostatistics at the Icahn School of Medicine at Mt. Sinai in New York, and colleagues. Phthalate mixtures, the report noted, can impact “neurobehavioral development,” with other studies finding links to aggression, inattention and rule-breaking behavior in boys from prenatal exposure. Gennings adds that even healthy children face similar risks from plastics chemicals still commonly found in baby bottles.

And studies show even the most cautious parents may not be able to escape the sins of the past.

Over the past 10 years, new research in the field of epigenetics, which studies how behavior and environmental exposures can affect how genes work, has found increasing evidence that harms from chemical exposures may become inherited. The chemicals change how the body operates, passing the changes down through two or three generations, and maybe even more. While the effect is well-established in animal studies, researchers are now going about the much more difficult task of studying people and sorting correlation from causation, according to Carrie Breton, an environmental epidemiologist at the University of Southern California who published a review of recent research on epigenetics in 2021.

But for Breton, the data linking some chemicals to toxic effects is already strong enough to warrant action, even if the exact mechanism– epigenetic or otherwise– is not yet fully understood.

“Should we understand how it’s happening? Can that help inform interventions? Yes,” Breton said. “But from a policy point of view… If we have evidence of that harm, we should be able to start regulating and doing something about it now.”

Why chemicals in consumer products aren’t better regulated

Sixty-one years ago,marine biologist Rachel Carson wrote “Silent Spring,” a book often hailed as revolutionary for its compelling communication of the risks of pesticides and other substances. The book is credited with helping propel a popular movement that led to the creation of the EPA, as well as the federal Clean Water and Clean Air Acts, which have dramatically reduced environmental pollution over the past half century.

But, experts say, health threats from commercial chemicals remain fundamentally the same. So what went wrong?

Sarah Vogel, senior vice president for healthy communities at the nonprofit Environmental Defense Fund, says U.S. environmental standards have improved in some ways since the publication of “Silent Spring,” especially in the first few decades after the book was published. Urban waterways like Ohio’s Cuyahoga River aren’t catching on fire anymore. Neighborhoods are no longer being sprayed with DDT, which has been linked to breast cancer, hypertension and obesity in the daughters of women exposed to the bug killer. Vogel’s organization and others successfully pushed for a widespread ban of the pesticide in the U.S. in 1972.

Progress on chemicals in consumer products, however, has lagged behind, Vogel said.

“On the chemicals piece – chemicals that are going into everything from paints and carpeting, cars and planes and all the rest of it – just think about what’s happened in the marketplace,” Vogel said. “Think of the complexities of plastics that we use now. There have been a lot of new chemicals we’ve produced.”

In conversations with policy experts like Vogel and researchers like Gennings, the Toxic Substances Control Act (TSCA) of 1976 inevitably becomes a centerpiece. One of the last major pieces of federal legislation from the environmental era of the 1960s and ‘70s, the law is also one of the weakest, experts say.

Ostensibly designed to enable the EPA to collect information on chemicals from the companies that created them and ban the ones found to be unacceptably toxic, experts say the law had major flaws from the start. Perhaps none loom larger than the law’s “grandfathering” of tens of thousands of chemicals already in the marketplace, removing most from scrutiny. Vogel says the law was further diminished by rollbacks and budget cuts.

“TSCA effectively became a dead letter law,” Vogel said, meaning its original intentions were gutted. 

In one of the most significant moments in the law’s history, in the 1980s EPA moved to ban asbestos, a well-known carcinogen. But a 1991 U.S. Court of Appeals decision tossed out most of the rule, weakening the power of TSCA, and the administration of President George H.W. Bush declined to appeal. Contrary to popular belief, asbestos remains legal for various uses today. 

“That really kneecapped the EPA,” said Melanie Benesh, legislative attorney for the nonprofit Environmental Working Group. “It made it much more difficult for them to do much for existing chemicals.”

In 2016, the U.S. Congress passed the Lautenberg Act, which overhauled the 40-year-old Toxic Substances Control Act and gave the EPA new authority, leading to the creation of two separate programs at the agency to review old and new chemicals. The agency announced a plan last year to fully ban asbestos.

But policy specialists like Vogel are withholding judgment on the significance of the reform as the Biden administration makes its mark, introducing new regulations on PFOA and similar chemicals in drinking water and evoking TSCA to potentially regulate 10 more toxic substances, including those used in rubber, plastics and fuels.

Although the EPA told The Examination it agrees TSCA “largely failed to serve its purpose” over its first four decades, it said the 2016 update allows the agency to “effectively protect human health and the environment” through a slew of new mandates and regulatory authorities.

“Despite facing a massive increase in responsibilities and statutory deadlines from the most significant piece of environmental legislation enacted in a generation, the [Trump] Administration never asked for any additional resources to implement TSCA,” the agency said. “Still, we’ve taken the resources we have and managed to make significant progress.” 

For its part, the American Chemistry Council says it has "consistently called attention to challenges with TSCA" and supports the law.

“We are fully committed to advancing progress and continuous improvement in the TSCA program and will continue to work with EPA and other federal agencies to strengthen our regulatory system,” it said.

But others say the numbers tell the story. Kyla Bennett, a former EPA employee and current director of science policy at the nonprofit Public Employees for Environmental Responsibility, told The Examination that at recent rates of review, it would take thousands of years to assess all 86,000 chemicals currently approved for use.

EPA staff interviewed by The Examination say the agency’s chemical programs remain understaffed, overwhelmed and burdened by still-ineffective regulations and a persistent culture that enables the chemical industry instead of counterbalancing it. 

Martin Phillips, an EPA chemist, was reassigned from the agency’s new chemicals program in 2020 after filing a whistleblower complaint. In an interview, Phillips noted that the EPA is currently assessing risks associated with asbestos, phthalates and ethylene dibromide — a fuel additive considered highly toxic and likely carcinogenic — nearly 40 years after Bill Drayton, a former EPA assistant administrator, warned in a report that the agency was moving too slow to regulate them.

“The agency felt it had enough information back then to regulate the chemicals, but that regulation hasn’t happened in 39 years,” Phillips said.

Cancer isn’t the only health risk from modern chemicals

Cancer is perhaps the first ailment that comes to mind when most people imagine the risks of chemical exposure. And with good reason: The disease is the number two killer in the U.S. and remains a persistent threat from many modern chemicals, researchers say.

But a focus on cancer can obscure other risks, including heart disease, which kills 90,000 more people annually.

Philip Landrigan, a world-renowned epidemiologist and director of Boston College’s Global Public Health Program and Global Observatory on Planetary Health, has been at the forefront of efforts to restrict toxic substances like lead and asbestos for decades. While asbestos is a potent carcinogen, lead impacts many parts of the body, including the brain and bones. Perhaps deadliest is its damage to the kidneys, which Landrigan says likely increases blood pressure and hypertension, raising the risk for heart disease and stroke.

“Cancer is a frightening disease,” Landrigan said. “But actually a larger number of pollution-related deaths are due to heart disease and stroke.”

Vogel says that over the past several decades, advancements in the understanding of the human genome, microbiome and other bodily systems have allowed researchers to begin developing a better picture of these types of non-cancer risks from exposure to even very small amounts of chemicals. 

One of the most alarming varieties is “endocrine disruptors,” a moniker given to any substance that interferes with the body’s transmission of hormones – or even mimics them. This causes cascading effects in the body that may be difficult to predict or understand, impacting metabolism, energy levels, reproduction, development and mood. Scientists believe that many “forever chemicals,” including PFOA, operate this way by accumulating in the body and tinkering with its organs and systems.

Birnbaum, the former director of National Institute for Environmental Health Sciences, compares the effect to medicines such as birth control pills. Like medicines, commercial chemicals also alter the body’s processes. 

“You’re changing the hormonal environment, which has an impact,” Birnbaum said. “The difference between drugs and chemicals that we get exposed to via consumer products is that drugs have to be tested before they go on the market. Chemicals that are in commerce don’t.”

Endocrine disruptors can compound the risks of exposure to other toxic substances. Landrigan points to Bisphenol A, a plastics chemical American parents are perhaps most acquainted with because of the packaging of baby products marked “BPA-free.” Landrigan says research shows BPA, like lead, contributes to heart disease, likely by modifying cholesterol levels and increasing atherosclerosis. 

But it’s endocrine disruption during pregnancy and early childhood– what Landrigan calls “the first 1,000 days of life”– that most keeps researchers up at night.

“That’s when the organ systems in a child’s body are being formed,” Landrigan said. “The development of the brain, lungs, the immune system, the reproductive organs… It doesn’t take much to derail them.” 

Studies show phthalates and polychlorinated biphenyls, or PCBs, both endocrine disruptors, can cause brain injuries in children, showing up as reduced IQ later in life, Landrigan says. Phthalates and BPA can also cause anatomical defects in the genitals, difficult to detect at birth but which present years later as reduced fertility.

The health effects of endocrine disruption can be impossible for an individual to link to chemical exposure because they’re hidden among a sea of other variables, such as parenting, education, and chance. While developing a rare cancer can raise suspicions, it’s harder to comprehend how a chemical alters a child’s behavior or silently kills an adult by adding a few points of cholesterol. 

For some, the chemical effect will pale in comparison to other factors. But for an unknown percentage, it will be just enough to harm or kill.

“And multiply that by millions of people,” Landrigan said.

Changing how chemicals are regulated

Chemicals are everywhere in modern society. 

The phthalates that Genning’s research shows enter the bodies of babies in neonatal units likely come from the breathing apparatus they could otherwise die without. A slew of PFAS chemicals are integral in the manufacturing of microchips, the little squares of silicon and circuitry that constitute the essential, electronic flesh of the modern world. 

Gennings says the idea that people must choose between enjoying all the benefits of modern technology, or maintaining autonomy over their own bodies, is a false dichotomy. For example, she said, if certain types of breathing apparatus expose babies to fewer phthalates, simple awareness and selection of the better equipment could drive down exposures while still providing life-saving technology.

Ultimately, Gennings believes everyday Americans should be a part of the decision making process about what chemicals and products are worth the risk. But that also requires they have the necessary facts.

“People need to know about the chemicals they are exposed to. How can you make an informed consumer decision without knowing how to balance risks and benefits?” Gennings said.

Wagner, the University of Texas at Austin School of Law professor, doesn’t trust industry to be forthcoming. In 2008 she co-authored a book titled “Bending Science: How Special Interests Corrupt Public Health Research.”

Wagner has laid out a series of steps she believes the EPA could take to better regulate chemicals and the companies that produce them. The proposals include requiring chemical companies to do more robust toxicity research and provide easy-to-understand analysis of a chemical’s risks and benefits to the EPA and the public. That would offload much of that work from the EPA and allow the agency to focus instead on enforcement. 

But many experts also say that the EPA must update its thinking about chemicals and human exposure. Right now, hazards are primarily assessed chemical-by-chemical, with little attention paid to the effects of cumulative exposure or the substitutes that pop up to replace dangerous ones. Instead, they say, the EPA should ban entire classes of chemicals and create new regulations that consider cumulative risks from chemicals known to target the same organs.

The EPA told The Examination it’s already thinking along these lines. For example, the agency said that earlier this year it released a “proposed approach” to assess the cumulative risk of phthalate chemicals, and is also working to break hundreds of PFAS chemicals into subclasses based on shared characteristics.

“The agency is focused on improving its ability to address multiple chemicals at once, thereby accelerating the effectiveness of regulations, enforcement actions, and the tools and technologies needed to remove PFAS from air, land and water,” the EPA said. 

Landrigan, the 81-year-old Boston College epidemiologist, takes the long view. Over his decades-long career, he’s worked with scientists and lawmakers to slowly but surely diminish the seemingly intractable global health threats of lead and asbestos. He’s optimistic it can be done again.

“There’s that old parable: ‘When’s the best time to plant a shade tree?’” Landrigan said. “The answer is 20 years ago. But the second best time is now.”

Editor’s note: Tracey Woodruff, director of the Program on Reproductive Health and the Environment at the University of California, San Francisco, is a member of The Examination’s advisory council.