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Scientists are studying the health effects of a group of chemicals used in clothing and furniture and cookware - a lot of products. And the initial research is suggesting that some of these chemicals are toxic. Here's more from NPR's Rebecca Hersher.
REBECCA HERSHER, BYLINE: PFAS, per- and polyfluoroalkyl substances, are manmade chemicals. They're super useful because they're resistant to water and oil and heat. PFAS help make clothing waterproof. They keep food packaging from sticking to food. They're used in non-stick pans and stain-resistant upholstery and special foam for fighting hard-to-put-out fires. Their usefulness has led the chemicals to end up everywhere.
LINDA BIRNBAUM: We're finding them contaminating many rivers, many lakes, many drinking water supplies. And we're finding them not only in the environment, but we're finding them in people.
HERSHER: Linda Birnbaum is with the National Institutes of Health. She says PFAS use has increased over the last 20 years or so. And at this point...
BIRNBAUM: Essentially, everyone has these compounds in our blood.
HERSHER: It's everywhere, and that sounded the alarm among scientists. The federal government is pumping extra money into research about how PFAS chemicals affect our health, but it's slow going. For one thing, there are at least 5,000 different PFAS chemicals. The handful of PFAS varieties that have been studied seem to be associated with some not-great health effects.
One big study looked at people in West Virginia and Ohio who were exposed to high levels of two PFAS varieties. It found elevated incidences of thyroid problems and certain cancers. Smaller studies have suggested some PFAS chemicals might hurt our immune systems. Birnbaum says...
BIRNBAUM: I think we have growing information that at least some members of this class can be problematic.
HERSHER: That's led some states - among them, Michigan, Colorado, New Jersey, and Washington state - to regulate some PFAS chemicals. In North Carolina, where an entire river basin is known to be contaminated, the state is surveying residents about their health.
At the federal level, the EPA has said it doesn't have enough information yet to set a nationwide safety limit on PFAS in drinking water. And politicians are talking about PFAS too. It's in the presidential race. Here's Senator Kirsten Gillibrand in New Hampshire last month.
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KIRSTEN GILLIBRAND: The worst thing about it for me, as a mother, is the fact that parents are so worried. They're bathing their children in this water. They're cooking with this water. They don't know what the impact's actually going to be.
HERSHER: And that last part, the uncertainty, is the crux of what's going on with PFAS right now because a lot of people have questions that scientists just don't have answers for yet.
ALISSA CORDNER: There's so much uncertainty around what the scale and the consequences of contamination are.
HERSHER: Alissa Cordner is a sociologist who studies PFAS. She says there's a growing demand for basic info about the chemicals, info like, how do I know if there are PFAS chemicals in my water? She and her colleagues have started a public list to keep track of which drinking water supplies have been tested for which chemicals.
CORDNER: There is a lot of ongoing water testing in some states, but it's not happening universally around the country. And in terms of individuals wanting to know, what's in my drinking water, the testing is still prohibitively expensive.
HERSHER: That's because PFAS are difficult to test for. And if you find out your water is contaminated, most in-home water filters can't remove the chemicals effectively. With not a lot of solutions or information to go around, the pressure is on scientists.
The National Institutes of Health is funding dozens of PFAS studies, including research that can look at about a hundred PFAS chemicals at once. The goal is to break the thousands of PFAS varieties into a handful of subgroups, make it easier to find out if some PFAS varieties are more toxic than others. It will take about two years to get there. In the meantime, Birnbaum says...
BIRNBAUM: A question that we all need to be asking is, what's essential? Do we really need it? Are there some places where we have to have this class of chemicals to be safe? But if that's the case, we would like them used in closed systems, so they don't escape and end up contaminating the whole world.
HERSHER: Rebecca Hersher, NPR News.
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