This is the second article in a three-part series by investigative reporter Liza Gross, exploring the most dangerous toxins found in the average American home. The stories track fertility, pregnancy and early childhood development. The first, on phthalates, can be found here.
Nikki Aldrich can’t talk about what happened in their bucolic riverside village without crying. “She lets me do the talking,” said her mother, Loreen Hackett.
Hackett and her daughter’s family live in Hoosick Falls, New York, where residents learned in 2016 that for years — including while Aldrich was carrying her first two children — they’d been drinking water contaminated with perfluorooctanoic acid, or PFOA, a toxic chemical that a local factory once used to make Teflon products.
When Hackett and her daughter’s family had their PFOA blood levels checked by the state, they were shocked by the results. Blood levels for her grandson, then 6, and granddaughter, who was 4, were both more than 50 times the national average of roughly 2 parts per billion for kids and adults. They now both suffer from illnesses that studies have linked to PFOA or similar chemicals, Hackett said.
PFOA is one of the most widely studied members of a family of more than 4,700 chemicals called per- and polyfluoroalkyl substances, or PFAS. The chemicals are found in hundreds of consumer products, including stain- and water-resistant furniture, outdoor gear, cosmetics, dental floss and disposable food packaging.
Scientists think these widely used industrial chemicals may harm pregnant women and their developing babies by meddling with gene regulators and hormones that control two of the body’s most critical functions: metabolism and immunity.
More disturbing, PFAS can also alter levels of both mothers’ and babies’ thyroid hormones, which oversee brain development, growth and metabolism, and also play a role in immunity. Prenatal PFAS exposures that disrupt metabolism and immunity may cause immediate and lasting effects on both mother and child. Women exposed to PFAS during pregnancy have higher risks of gestational diabetes and pre-eclampsia, a type of high blood pressure. Their babies are more likely to undergo abnormal growth in utero, leading to low birth weight, and later face increased risk of childhood obesity and infections.
A major producer of PFAS in the United States, 3M, dismisses these findings. “PFAS is a broad category, including thousands of substances with diverse physical and chemical properties, uses, and characteristics,” said Sean Lynch, a 3M spokesperson. “While the science behind PFAS is complex, the weight of scientific evidence does not show that PFOS or PFOA, two types of PFAS, cause harm in people at current or past levels.”
Epidemiologists generally can’t pinpoint the cause of a person’s gestational diabetes or obesity, said Philippe Grandjean, M.D., Ph.D., an environmental epidemiologist at the Harvard T.H. Chan School of Public Health. But on average, they can see that PFAS increases the risk of health problems such as metabolic disease and immune deficiency.
Manufacturers treat products from raincoats to pizza boxes with PFAS because they repel water, heat and grease, thanks to the unique properties of their superstrong fluorine-carbon bonds. These bonds make PFAS so resistant to degradation they’re called “forever chemicals” by some scientists.
And their widespread use has left nearly everyone exposed. As the chemicals linger, they concentrate in blood, breast milk and numerous tissues. Scientists are particularly concerned pregnant mothers might pass on the chemicals through the placenta, which manages the baby’s metabolic needs while guarding against infection.
Anecdotal reports from over a century ago showed that toxic substances like morphine and lead cross the placenta but it was long assumed that most chemicals did not. In 1981 DuPont scientists analyzed the umbilical cord blood of workers’ newborns and found that PFAS crossed the placenta, but they did not publish the finding.
Federal law requires companies to inform the Environmental Protection Agency immediately if they learn a chemical poses risks to human health or the environment. The EPA filed a complaint against DuPont in 2004 for failing to report its finding, after receiving internal documents obtained through a separate lawsuit.
“Scientific evidence confirms that the trace amount of PFOA found in this one data point would pose no risk to human health,” a lawyer for the company responded. “In the absence of substantial risk of harm, the information is simply not required to be reported.”
Only in the past few decades have scientists developed the analytical tools to systematically identify and measure these toxic intrusions during pregnancy. They now know that PFAS simply follow the same rules that nutrients do, said Dr. Grandjean. “And with PFAS, we can see they basically all pass through the placenta.”
That means newborns can get a double dose of PFAS, first in the womb and then when they nurse. The few studies that examined children under the age of 2 found PFAS levels increase during the first six months, likely from breastfeeding.
Most of what scientists know about risks associated with PFAS comes from people living in communities like Hoosick Falls or exposed on the job. Yet everyone is contaminated at some level, said Bruce Lanphear, M.D., professor of health sciences at Simon Fraser University in Vancouver.
“And while we understandably focus on highly contaminated communities,” Dr. Lanphear said, “we can predict, based upon all the other evidence, that there’s unlikely to be any safe level.”
Scientists are most worried about how PFAS affect the rapidly developing bodies of children in the womb, and soon after birth. “Minuscule amounts of these exposures can have serious and lifelong consequences,” said Leonardo Trasande, M.D., a children’s environmental health expert at New York University.
Hackett’s grandson has bone problems linked to a very low birth weight. Her granddaughter had two severe staph infections that required massive doses of several different antibiotics to recover. Both conditions have been tied to PFAS exposure.
“There’s rising evidence that kids who are exposed to PFAS get more infections,” said Dr. Trasande. Children exposed to PFAS in the womb and early infancy also show reduced immune responses to vaccinations.
Such associations are merely “leads to explore” rather than evidence of causation, a 3M spokeswoman said in testimony before a U.S. House hearing on PFAS contamination and corporate accountability last year. “There’s no cause and effect for adverse human health effects at the levels that we are exposed to as a general population,” she said.
Not everyone agrees. When Hackett’s youngest grandchild was born, after they stopped drinking the water, she “absolutely forbade” her daughter to breastfeed. The baby was 5 weeks old when she started having seizures — the doctor later attributed the seizures to a thyroid disease that’s also linked to PFAS.
Hackett’s friend Emily Marpe, from nearby Petersburgh, never suspected her children had been exposed to PFAS until an official from the state health department called.
“The first thing he said was, ‘You guys need to stop brushing your teeth right now with tap water,’” Marpe said. Then he told her they found PFOA at 2.1 parts per billion in her water — more than five times the EPA’s voluntary guideline at the time. She fell to her knees and started dry heaving. “My well had just tested higher than the entire village of Hoosick Falls.”
Marpe, who lived near Taconic Plastics, which also made Teflon products, quickly became the town’s unofficial PFOA expert. She read about how a DuPont Teflon factory had contaminated the water around Parkersburg, West Virginia, from the 1950s until the early 2000s, and an independent panel of epidemiologists had found a “probable link” between PFOA and several health problems, including pregnancy-induced hypertension and thyroid disease.
New York listed the Taconic Plastics facility as a state Superfund site in 2016, and the company agreed to cover the costs of removing PFOA from private and public water supplies in Petersburgh.
When Marpe realized she was pregnant, she agonized over the thought of exposing another child to these chemicals. Her blood PFOA level had tested 160 times the national average and she seriously contemplated an abortion. “I still feel guilty for even thinking about it,” she said.
She went through with the pregnancy but every ultrasound appointment sent her into a panic, worrying about birth defects seen in a baby born to a Teflon worker. Eliana was born several pounds lighter than her two older children, but was otherwise healthy.
A review of international studies published in August found “particularly strong” evidence linking pregnant mothers’ PFAS exposures to increased risk of having low-birth-weight babies. The review also found strong evidence linking prenatal PFAS exposures with impaired glucose tolerance, or “pre-diabetes,” and gestational diabetes in mothers, as well as childhood obesity. Scientists think the chemicals’ ability to alter a mother’s glucose metabolism may contribute to these risks.
“PFAS appear to slow your metabolism,” said Dr. Trasande, who led the review. And he wouldn’t be surprised if they contributed to diabetes because they disrupt proteins that regulate sugar and fat metabolism.
Babies born to mothers with gestational diabetes and those born below average weight both face an increased risk of obesity. That gives PFAS two paths to predispose a child to obesity: by upsetting the metabolism of the mother or of the developing baby.
Disrupting a mother’s metabolism may also change the placenta in a way that lets more PFAS through. Last year a study showed women with gestational diabetes may transfer higher PFAS levels to their babies. Youssef Oulhote, an environmental epidemiologist at the University of Massachusetts who led the study, suspects that PFAS may make the placenta more permeable. In other words, PFAS may cause a condition that allows even more of them to get to the baby.
Marpe didn’t have gestational diabetes, but her body passed plenty of PFAS to her baby. When she tested Eliana at 7 weeks old, two years since she’d stopped drinking the contaminated water, her baby’s PFOA blood level was 75.9 parts per billion, higher than most people in Hoosick Falls.
Marpe had breastfed both of her older children, and knew that babies ingest PFAS when they nurse. Her baby’s levels were already high, so she decided against breastfeeding the third. “That was one of the hardest decisions I’ve ever made,” she said.
Regulating for future generations
Rebecca Fuoco, science communications officer for the nonprofit Green Science Policy Institute, took steps to limit her PFAS exposures before she even conceived. When she moved into her Los Angeles house two years ago, she replaced the carpet and did her best to make sure none of her furniture, clothing or other items contained PFAS.
But avoiding food-related exposures while pregnant proved harder. She had a deep knowledge of PFAS from her job and even tapped experts for advice, but she was also tired and nauseous and packaged food was easy. “Sometimes cooking from scratch felt impossible, like juggling on a tightrope,” she said.
Plus the chemicals aren’t typically disclosed on labels. “Even with all the advantages I had, it was impossible for me to completely eliminate my baby’s exposure because PFAS are ubiquitous and invisible.”
Eight chemical manufacturers agreed to stop making the so-called long-chain PFOA and PFOS in the United States by 2015 because of health and environmental concerns. But they’ve switched to short-chain varieties — with shorter carbon backbones — that also accumulate in people’s tissues and may prove just as toxic.
Regulations don’t require companies to determine whether a chemical crosses the placenta or passes through mother’s milk, said Dr. Grandjean. “What’s so frustrating is that we’ve been chasing a train that already left the station. We are decades too late.”
The European Food Safety Authority, in contrast, calculates the lowest PFAS dose that can harm an infant, and figured out how much a mother would have to ingest for her baby to exceed that amount. They arrived at a weekly intake of 0.008 parts per billion in food — a fraction of most women’s levels — though this is not yet enforced by law.
The United States EPA hasn’t implemented an enforceable PFAS water-quality standard, but New York is set to adopt standards seven times lower than the agency’s guidelines. And the state’s legislators passed a bill to ban PFAS from food packaging materials in July.
Loreen Hackett, who’s advocated for PFAS regulation since blood tests revealed her family’s sky-high PFOA levels, testified at every hearing. When she looks at her grandchildren, she can’t help but wonder if they’d still have health problems if they hadn’t grown up drinking Hoosick Falls’ contaminated water. That’s why the food packaging bill was so important to her. “With our levels,” she said, “we can’t afford another ounce of this stuff.”
Liza Gross is a science and health journalist and author of “The Science Writers’ Investigative Reporting Handbook.”