“We’re all exposed, we all have these chemicals in our bodies, and they’re around us everywhere.”
They’re in our water, our soil, our dental floss, mascara, hidden in our pizza boxes, our raincoats, our paint, in our tampons, our vegetables, our sneakers. (And the list goes on and on…) Perfluorinated and polyfluorinated alkyl substances, better known as PFAS, are everywhere — and there’s a growing body of evidence they may be harmful to our health.
These chemicals were developed in the 1930s and found to be highly effective at repelling water and oil, and protecting against high heat, making them ideal for use in food wrappers, nonstick cookware, and fire suppressants. Over time, they’ve found their way into many other common household products, too. Because of their ubiquity, they’re accumulating in the environment, and even inside our bodies. That’s because these substances have bonds so strong, scientists aren’t even sure how long it will take them to degrade. They could last for hundreds or even thousands of years, which is why they’re commonly called “forever chemicals.”
Recently, they’ve been linked to a dizzying array of conditions, from high cholesterol to diabetes and cancer. What parts of our bodies aren’t affected by PFAS? “Frankly, I’m not sure I can think of a tissue or an organ system,” says Linda Birnbaum, former director of the National Institute of Environmental Health Sciences and the National Toxicology Program. “I think we should all be worried about how we are being exposed and why we’re being exposed,” she says. We turned to Birnbaum for an in-depth look at how these toxins affect the body, where they’re hiding within our cells, what’s being done to get them out of our water, and how you can protect yourself.
Katie Couric Media: When did we first recognize that PFAS could pose health risks, and that this contamination was an environmental problem?
I think the wake-up call was around 1998 or 2000 when 3M, which was the sole manufacturer of one of the first PFAS that had been extensively used, announced that they would no longer be producing it, because it had been found in the blood of the general population. Until that point, there wasn’t a lot of concern. I think people didn’t realize it had gotten out, and I think we thought that it was contained — that the only place it might be an issue was with workers handling the substances. We now know that’s not the case.
What do we know about how exposure affects the body?
There are many, many health effects associated with PFAS. A large study was done in the Ohio River Valley, because of the contamination that was caused by DuPont, where Teflon and other chemicals were made. What was shown was that there were liver effects, high cholesterol, cancer — both of the testes and the kidneys — effects on the immune system, on hypertension during pregnancy, on endocrine disruption, and on thyroid systems. There was also evidence [linking them to] preterm birth and low birth weight.
There are many other effects that are now being reported, such as heart disease. Frankly, I’m not sure I can think of a tissue or an organ system in our bodies which hasn’t been reported to be affected by PFAS.
And in almost all cases, what’s been seen in human observational studies, we’ve also seen in experimental animal studies. I’m not just talking rats and mice, but in monkeys and birds and fish. We know that, for example, in the Ohio River Valley it definitely affected the cows and sheep in the area.
When did officials start to think about preventing dangerous levels of this stuff from getting into our products or water?
I’m gonna tell you the bad news, which is that these chemicals in our country are barely regulated. Back around 2000 or 2002 after 3M’s announcement, EPA enacted a significant new use rule — called a SNUR for short — which basically said, “You can’t start using this one particular chemical again unless we approve it.” There have been a couple other SNURs that have come out for other specific PFAS, and there’s a big push now to regulate them in consumer products.
They haven’t been regulated in drinking or groundwater at the federal level. But in March of this year, EPA actually proposed maximum contaminant levels, which would be the first time at the federal level that we’d have regulations. None of these things have come about yet, but I know EPA is hoping to finalize the regulations by the end of this year.
I should say that when EPA releases these standards, they’re based upon what’s considered doable, not what’s risk-free. In fact, EPA said the maximum contaminant level goal for PFOA and PFOS is zero, because they’re both human carcinogens.
In your view, how strong are these regulations? Do we need to be going further?
I think it’s very important that EPA has come out with these levels. They’re proposing four parts per trillion, which is a very small limit, and I applaud them for proposing that. Would I like to see it be more stringent? Of course. But I’m a pragmatist. I think [that limit] will have a huge impact and I think it’s a good start.
I personally — and I’m not the only one to feel this — think we need to look at PFAS as a class, instead of regulating individual chemicals. It has taken more than 20 years to generate enough data for EPA to propose rules for a total of six of more than 10,000 PFAS. We’ll never finish this in any of our lifetimes if we continue to go one chemical at a time. We can continue to test, but at the same time, the levels of these chemicals in the environment and in us would increase. At this point, we really don’t have a good way to get rid of these chemicals. We’ve been using them for the past 60 years — they’re in almost all our water supplies, soil, and sediment. The fish swimming in that water and many of the vegetables being grown in it have been contaminated too, as well as domestic animals, like cows, sheep, or pigs.
Is there a push to ban PFAS?
I think stopping the production of PFAS is extremely important. We’ve really got to turn off the “tap,” certainly for uses that aren’t essential, like stain repellents. There are some medical products where the chemical is needed that we can continue to use.
I should say that 3M, which was a major producer, along with DuPont and a couple other smaller companies in the U.S., announced that by the end of 2025 they’ll no longer make or use any PFAS.
Do you have guidance for how we can protect our water?
When these maximum contaminant levels go into effect, you’ll be notified if your water system exceeds the regulation. In that case, your municipal system will be working to install filtration. But we also need to remember that there are tens of millions of people in our country who are on well water, which is never regulated. So if you are drinking from a well, and if you’re anywhere near a fire-training facility, a defense facility, or places where there’s been a major fire, you may want to get your well water tested.
You can filter these chemicals out of your drinking water. We don’t know how to get them out of an entire contaminated river system or groundwater, but for your individual use, you can use filters to remove PFAS from your drinking water. There are GAC or granular activated charcoal filters, which is what’s in most refrigerator filters. But it’s important that you change them, because otherwise they can become saturated with these substances and you can become exposed that way. There are more expensive methods you can use, like the filter systems that go under your sink, which use reverse osmosis and iron exchange. Reverse osmosis is probably the most effective, but from my understanding, requires more upkeep than the GAC.
Should the average person be worried about their PFAS exposure?
I think there’s no use worrying about everything. We’re all exposed, we all have these chemicals in our bodies, and they’re around us everywhere. I can’t spend all my time worrying about what I can’t control, but I can try to control certain things. I can avoid known sources of PFAS, I can try not to buy things that are completely water-repellent or completely stain-resistant, and I can try to be sure that my drinking water isn’t contaminated.
This interview has been edited for length and clarity.
