New national standards for PFAS chemicals in drinking water : Short Wave Wednesday the Environmental Protection Agency announced new drinking water standards to limit people's exposure to some PFAS chemicals. For decades, PFAS have been used to waterproof and stain-proof a variety of consumer products. These "forever chemicals" in a host of products — everything from raincoats and the Teflon of nonstick pans to makeup to furniture and firefighting foam. Because PFAS take a very long time to break down, they can accumulate in humans and the environment. Now, a growing body of research is linking them to human health problems like serious illness, some cancers, lower fertility and liver damage. Science correspondent Pien Huang joins the show today to talk through this new EPA rule — what the threshold for safe levels of PFAS in tap water is, why the rule is happening now and how the federal standards will be implemented.

Read more of Pien's reporting on the EPA's first ever rule on PFAS in drinking water.

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What to know about the new EPA rule limiting 'forever chemicals' in tap water

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EMILY KWONG, BYLINE: You're listening to SHORT WAVE from NPR.


Hey, SHORT WAVErs. Regina Barber here with science correspondent Pien Huang, and she's been reporting about a new rule that affects our drinking water.

PIEN HUANG, BYLINE: Hey, Gina. Yeah. So this new final rule from the Environmental Protection Agency announced on Wednesday - it puts a limit on the amount of certain chemicals in our drinking water that are called PFAS.

BARBER: OK. I've heard of these. They're also called forever chemicals. But I have to admit, I really don't know what they are.

HUANG: It's understandable. PFAS stands for perfluoroalkyl and polyfluoroalkyl substances (laughter).

BARBER: OK. Those words are not familiar to me.

HUANG: (Laughter) Yeah, it's a bit of a mouthful. But the thing about these chemicals is that they don't exist in nature. They're human made, and they have a super strong carbon-fluorine bond. That's what they have in common. They're used for making materials that shed water or are resistant to grease, for example.

BARBER: Like my beloved nonstick pans. But if the EPA is limiting these chemicals, there's got to be a downside to them, right?

HUANG: Yeah, there is. So PFAS, as you alluded to, are called forever chemicals because they tend to stick around for a very long time, and they build up in people and animals and in the environment. Like, PFAS started showing up in products in the 1940s, and they don't break down for hundreds, maybe even thousands of years in nature. So...


HUANG: ...The ones that were made then are still around today.

BARBER: Oh, wow.

HUANG: And they were manufactured by a few well-known companies, like DuPont and 3M.

BARBER: I've heard of them.

HUANG: And these chemicals have been linked increasingly to many kinds of health problems - serious illnesses...

BARBER: Like certain cancers.

HUANG: Yep...


HUANG: ...Plus, things like lower fertility, high cholesterol and liver damage. So the EPA is now putting a limit on six PFAS in our drinking water out of the more than 12,000 PFAS chemicals out there.


BARBER: So today on the show, there's something in the water - PFAS. We get into the science behind what they are and how they can affect our health.

HUANG: Plus, more on this new EPA rule. It's a big deal because it's the first time the EPA has imposed enforceable limits on PFAS in our drinking water.

BARBER: You're listening to SHORT WAVE, the science podcast from NPR.


BARBER: OK. Pien, tell me more about PFAS, these forever chemicals that end up in our drinking water. Where do they come from?

HUANG: So they come from a lot of different places, like we were talking about earlier. They started showing up in products that people were buying in the 1940s, things that were waterproof and stainproof. So they were coated with things like Teflon and Scotchgard, and they were found in all kinds of products - floss, nonstick pans...


HUANG: ...Clothing like raincoats, makeup even, furniture. And then industrially, they were also used in firefighting foam and medical devices and semiconductors. And now, after so many years of use, they're found in the bodies of humans and animals.


HUANG: And because they have those strong molecular bonds, as we were mentioning, they're very slow to break down. They can build up in people in the environment. Even babies now are born with this in their blood.


HUANG: But the key for this rule is that they're even in our tap water, so hence why the EPA is now restricting them.

BARBER: OK. So are PFAS in our water because they get washed down our drains and introduced into our water systems?

HUANG: That's part of it. I think a bigger contributor, though, is the manufacturing process. So chemical factories have polluted the air and the groundwater around them. It's also a particular problem near some military bases and other places that have used a lot of firefighting foam where it's leached into the water supply.


HUANG: And once PFAS is in the tap water, people drink it. That exposure has been linked to immune and developmental damage in infants and children.

BARBER: Oof, that's really distressing. And I know that there's been a lot of debate about just, like, how harmful various PFAS chemicals are to humans.

HUANG: There has been, yeah.

BARBER: So is part of the reason this ruling is coming out now just because scientists are finding more definitive answers about how humans are affected by these PFAS chemicals?

HUANG: Yeah, that's definitely a part of it. So it's always hard to draw perfect links between specific individual chemicals and human health because we're all exposed to so many of them, and it's really not ethical to do, like, direct human testing to establish levels of harm. I mean, even as recently as 2016, NPR has reported that the EPA said that PFAS were not a threat at low levels, which - they said at the time, at 70 parts per trillion. But then by October 2021, the EPA released a PFAS strategic roadmap with three goals. And the very first goal of that was just literally research - investing in research, development, innovation, to really sort of understand how PFAS chemicals affect human and environmental health and to understand which interventions would actually be effective. And...


HUANG: ...That research is really needed because, you know, Gina, I know you know this, but just because a chemical is ingested, it doesn't mean that it will be harmful. The thresholds matter, you know?

BARBER: Right.

HUANG: For example, cyanide in apple seeds.

BARBER: (Laughter).

HUANG: They're in all the apple seeds, but it's safe to eat them. So the level of chemical really matters, and the case is different for certain PFAS. You know, the EPA now says that even tiny amounts of two specific types of PFAS called PFOA and PFOS pose health risks.

BARBER: OK. So the EPA just put a limit on six PFAS chemicals. What are current levels? And how will it change under this new rule?

HUANG: So it's not totally clear what the current levels are across the board. Some communities have been super proactive in monitoring, but it's not been required in many places. So that's what these first three years of monitoring will establish. How much PFAS is in the water and whether it exceeds these new thresholds from the EPA. Then those that do exceed those thresholds will have an additional two years to install water treatment technologies to lower the levels of these PFAS under the thresholds. There's a few ways they can do this. They can install filters or chemically treat the water. And these new PFAS thresholds are low. They're set at four parts per trillion to 10 parts per trillion for...


HUANG: ...A few - yeah, really, really low - for a few individual PFAS, depending on the chemical. And there's also now a limit on mixes of two or more of some of the PFAS on the list. The EPA says that they expect that these excess PFAS levels will be found only in about 6 to 10% of our water systems, but that would still affect some a hundred million people in the U.S., which is almost a third of our population.

BARBER: That's a lot of people and only a small number of more than 12,000 different PFAS. Like, what about the other thousands?

HUANG: Well, that is a lot of data and research to collect, and scientists are going to be studying PFAS for many years to understand the full extent of the possible ways they affect human and ecological health. Some people are even saying that it should be regulated in a blanket way as a class of chemicals. But for now, these are the specific chemicals that the EPA has a good amount of data on.

ELIZABETH SOUTHERLAND: The six that they have here have had many, many both animal and human studies in many cases so that they feel confident that they have estimated the safe level of these chemicals.

HUANG: That's Elizabeth Southerland, a former EPA official in the Office of Water. She told me that the new limits are a really bold first step towards addressing the PFAS problem. And while the EPA has only focused on these six chemicals, the treatments that water utilities use to remove them will also be taking other chemicals of concern out of the drinking water.

SOUTHERLAND: All kinds of pesticides, pharmaceuticals, personal care products that are unregulated now under the Safe Drinking Water Act but we know have serious health effects.

BARBER: This is good. And I'm guessing that the side benefit of other chemicals - like, you know, pesticides, pharmaceuticals she mentioned being filtered out - has happened in some states already - right? - because when I was prepping to talk to you, I read that some states already have limits on PFAS levels.

HUANG: Yeah, exactly. So there are a few states, you know, from Massachusetts to New Jersey to Washington, Wisconsin, that have already set standards for how much various PFAS chemicals can be in their drinking water. Those levels do vary by state, and a few others had some regulatory standards pending. This new EPA rule will help standardize those maximum contaminant levels and also establish which chemicals need to be filtered out at the national level.

BARBER: So how much is implementing this new rule going to cost?

HUANG: Yeah. So the EPA estimates that it's going to cost $1.5 billion...


HUANG: ...Each year for water companies to comply. And that's for every year, Gina, as long as they keep finding PFAS in the drinking water.


HUANG: Water utility interests actually claim that it could cost much more than that. But these figures include ongoing monitoring, maintaining equipment, you know, for instance, replacing carbon filters on a regular basis.

BARBER: I mean, it does sound doable, just very expensive.

HUANG: Yeah.

BARBER: So where is this money going to come from?

HUANG: So the EPA is providing $1 billion in grants to help water systems and even private well owners conduct that initial testing and treatment. That's part of this $9 billion funding package specifically for PFAS removal that's in the bipartisan infrastructure law. There's also a different source. Companies that made these chemicals are on the hook for more than $10 billion from a class action lawsuit. That money is supposed to go to public water systems to remove PFAS. But if water systems can't access those funds, if those funds run out, some of those costs may eventually get passed on to consumers, so it might start showing up in people's water rates as well.

BARBER: So the people you talk to, what do they think the long-term impacts of this decision will be?

HUANG: They think it's going to be pretty significant.


HUANG: I mean, the EPA says that even though it costs $1.5 billion a year, the benefits will equal, if not even exceed that cost. You know, there's going to be less cancer, fewer heart attacks, fewer strokes and birth complications in this population of 100 million people. Here's what EPA administrator Michael Regan said.


MICHAEL REGAN: One hundred million people will be healthier and safer because of this action. This action will prevent thousands of deaths and reduce tens of thousands of serious illnesses.

HUANG: And Anna Reade, who's lead scientist on PFAS for the Natural Resources Defense Counsel - they're an advocacy group - she shared a similar thought.

ANNA READE: This will protect communities that know they have PFAS contamination and have not been able to get relief and communities that have never known that they have contamination and will be getting relief anyways. And so that's really good.

HUANG: Now, this regulation is just for water, and if it's in the water, that's probably the main direct way that many people are getting exposed to it. But it doesn't address the other ways people might also be getting exposed to PFAS, like in their home products or in the food supply or from environmental pollution. And again, you know, we just want to say we don't know for sure what the dangerous levels of exposure are through these other routes.

BARBER: OK, so does this mean that these products we've grown accustomed to will start disappearing? I mean, I'm happy to give up my nonstick pans and, like, get better ones, but I'm also not opposed to having, like, you know, the best of both worlds.

HUANG: Yeah, well, right now, that's up to the manufacturers, and it's also a question of whether states are going to choose to put in regulations at the source. That said, there are a few companies that are coming up with alternatives. Nonstick pans can be made out of ceramic.

BARBER: I'm going to get some of those.

HUANG: And there are non-PFAS coatings that can be used for food packaging, rain gear, other products. So there is a growing list of alternatives out there, and places like the Green Science Policy Institute keep those lists.

BARBER: I like that we ended on hope, Pien. Thank you so much for bringing this story to SHORT WAVE.

HUANG: You're welcome, Gina. There's a lot more to come.


BARBER: Before we head out, I want to take a minute to talk about SHORT WAVE Plus. Plus subscribers help make shows like SHORT WAVE possible, and they get to listen to all of our episodes without any sponsor breaks. Find out more at And to everyone who's already subscribed, we see you, we appreciate you, and we thank you so much. This episode was produced by Berly McCoy and edited by our showrunner Rebecca Ramirez and Scott Hensley. Pien, Rebecca and Berly checked the facts. Beth Donovan is our senior director, and Collin Campbell is our senior vice president of podcasting strategy. I'm Regina Barber. Thank you for listening to SHORT WAVE from NPR.


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