I'm William Brangham and this is "Horizons."

What do non-stick pans, firefighting foam, and many of our couches, carpets, and cosmetics have in common?

They're all made with PFAS, the so-called "forever chemicals."

They've helped spur innovation, but they're also insidious to human health.

How did we get here and how can we protect ourselves?

Coming up next.

♪ Announcer: Support for "Horizons" has been provided by Steve and Marilyn Kerman.

Additional support is provided by Friends of the NewsHour.

♪ This program was made possible by contributions to your PBS station from viewers like you.

Thank you.

From the David M. Rubenstein Studio at WETA in Washington, here is William Brangham.

Welcome to "Horizons" from PBS News.

You may have heard of PFAS.

These are the so-called "forever chemicals."

They're called that because they're incredibly durable, resilient synthetic chemicals that have helped transform modern industry.

Teflon is a wonderful electrical insulator and resists a lot of moisture too.

Brangham: PFAS have been used in a vast array of products, everything from pots and pans to computers to dental floss.

They've made fabrics and carpets stain-proof.

They've kept us dry from rain and snow, and they've helped send satellites and rockets up into orbit.

But PFAS are also harmful to human health, and they have now spread everywhere on Earth.

So, for a deep dive into these chemicals and what we can do about them, we are joined by investigative journalist Mariah Blake.

Her powerful new book is called "They Poisoned the World," which tells the history of these chemicals and the destructive impact they've had on a few small communities in the U.S.

And by Laurel Schaider.

She's the senior scientist at the Silent Spring Institute in Massachusetts, where she studies the spread of PFAS chemicals in drinking water and what they do to human health.

Thank you both so much and welcome to "Horizons."

Laurel, I'd like to start with you.

One of the difficulties I have in reporting on environmental pollutants is there are so many things that people have to focus on, microplastics, phthalates, uh... you know, BPA, and all of these different things.

So very specifically, we are talking about PFAS.

Can you help us, for a lay audience, what are these chemicals?

Thank you so much for having me, William, as part of this important discussion.

PFAS are a class of highly persistent chemicals.

PFAS stands for per- and polyfluoroalkyl substances.

As you mentioned, they're also called "forever chemicals" because of their extreme persistence.

PFAS are added to a number of consumer products for their non-stick, stain-resistant, waterproof, and grease-proof properties.

They're also used as a class of firefighting foam called AFFF or aqueous film forming foam, which are used at military bases and airports and other places to fight flammable fuel fires.

As you mentioned, these are chemicals that are widely used in many consumer products.

Unfortunately, we also have learned that they're extremely persistent in the environment.

Some of them can also accumulate in our bodies.

Over 99% of the U.S.

population has PFAS in our bodies, and PFAS exposures have been linked to numerous types of health effects.

Brangham: Mariah, let's pick up on what Laurel is saying there.

The idea that we are... now know that these things are not good for us, and they are in all of us, when did we start to know that?

And tell us a little bit more about those health effects.

Well, there are two answers to that question, really, because industry and the U.S.

government were aware that these chemicals were potentially harmful for decades before the public and regulators and scientists became aware of this.

So the main manufacturers of PFAS, DuPont and 3M, have known since the 1960s that they were toxic.

They have known since the 1970s that they persisted in the environment indefinitely, and that they were accumulating in the blood of people all over this country.

They eventually discovered that this was true of people all over the world.

So 3M tested the blood of people all over the world, including places like remote rural China.

The only blood they could find that didn't contain these chemicals was collected from Korean war vets in 1952.

So really before these chemicals went into wide scale production.

Brangham: Wow.

And, you know, these findings prompted some alarm within these two companies, and they began studying their effects on animals and workers, and the results were pretty dramatic.

So, in one case, they tested one of these chemicals on monkeys, which were chosen because they're biologically more similar to humans than lab rats.

All of the monkeys died.

So the study actually had to be aborted early because all of the monkeys died.

Uh... But even more concerning were the results of their studies among workers, so... These are workers in the plants where they're making it.

Workers in the plants where they manufactured PFAS and Teflon, which is a type of PFAS and it's made with PFAS.

So as early as the 1970s and 80s, they began linking these chemicals to certain types of cancer, to hormone disruption, to markers of organ damage, and, you know, a wide variety of conditions, including in one case, DuPont discovered that a link between exposure, women who worked in its factories and birth defects in their children.

So... But none of this was ever reported.

None of this was reported to regulatory agencies.

The public was not made aware of it, and even independent scientists weren't made aware of it until much, much later.

So really, it wasn't until the 2000s uh... that these chemicals registered on the radar of regulators and scientists, and to some degree, the public.

And that was only because, more or less because of happenstance.

Brangham: I see.

Laurel, can you help us understand from a scientific perspective, if someone's watching this and thinking, "Oh my gosh, I have a GORE-TEX coat, "I floss my teeth, I breathe air and drink water," what is the mechanism by which these chemicals get into us?

So we can be exposed to PFAS in many different ways.

Drinking water is a common source of exposure.

It's been estimated that over 200 million Americans have PFAS in our drinking water.

Of course, there are some communities that have had quite high levels of contamination.

So certain communities have particularly high exposures.

Um... Beyond drinking water, we can be exposed to PFAS from food.

So the plants and the animals that we eat can absorb PFAS from their surroundings and certain PFAS can accumulate as you go up the food chain.

So more predator fish can have higher levels of PFAS.

We've also been exposed to PFAS from food packaging.

So for instance, microwave popcorn bags and fast food wrappers have traditionally been treated with PFAS to make them grease resistant.

And then consumer products can expose us to PFAS as well.

And the ways into our body are several-fold.

We can be exposed to PFAS through dermal contact.

So there's some potential for absorption for PFAS through our skin.

When we touch products that contain PFAS, they can get onto our hands.

And if you happen to be a child, put your hands in your mouth, the PFAS can be transferred from products into our bodies through hand-to-mouth contact.

Certain PFAS are also volatile.

So that means that they actually can end up in the air that we breathe in.

And then we don't think of dust as a reservoir for toxic chemicals in our homes, but a number of chemicals including PFAS can accumulate in the dust in our homes as well.

And we all breathe in a bit of dust every day.

And again, for children, they breathe more air, drink more water and eat more food per unit body weight.

So they can have relatively high exposures.

And because PFAS are used in such a wide array of products, we're all exposed every day for many different sources.

And, Mariah, you mentioned before that one of the great public discoveries was how certain communities in the U.S.

were really highly contaminated by PFAS.

Your wonderful book, "They Poisoned the World," details what happened with a couple of communities around Hoosick Falls, New York, where people were drinking contaminated water because of a couple of plants that were using the chemicals locally and they were drinking these for years and people discovered this.

And I want to play a little bit of sound.

We spoke to some of the people who were featured in your book.

This is a little bit of sound from Emily Marpe.

She's a mother and here she's describing her reaction when she found out that her children had shockingly high levels of PFAS in their blood.

Let's listen to what she said.

I don't think people would really get the scope of how it feels to be violated that way.

My children were violated.

Yeah.

Who has the right to do that?

Who?

I mean, you're altering their organs, their DNA, their blood, their health outcomes.

I mean, it's one thing if they decided to pick up a cigarette when they got older, chose to drink.

At least there's somewhat of a choice in that.

There was no choice in this.

What she, and I heard from so many people and it's so detailed in your book, is the sense of betrayal that people thought surely there was some organization, governmental entity looking out to make sure that the water we drank was okay.

Yeah, so, and Emily Marpe, the woman who just spoke, this is a young mother.

She put everything she had into a dream home for her family only to discover that this private well, that the private well was contaminated with these toxic chemicals that industry and government have known for decades were harmful.

And the sense of devastation and betrayal, it's hard to convey.

But, you know, and millions of people around the country are going through a similar kind of realization right now as more and more people learn their drinking water is contaminated.

And it's not always with levels as high as in Hoosick Falls and the neighboring community where Emily lived.

But I think that, yes, people generally have the sense, they implicitly trust that there are systems in place to protect them.

And when they learn those systems don't exist, when that faith is broken, it is incredibly devastating to a lot of people.

I mean, they're dealing with the fallout for their families, the concern about their family's health, um... all the logistical challenges that come with living, you know, living with a contaminated well or contaminated drinking water, but also they lose their faith in the system to protect them.

- Brangham: Right.

- Yeah.

And yeah, I mean, I think that Emily conveys it very well.

It's like, who has the right to do that?

But these companies have done that, you know, to all of us to a degree.

They put these chemicals out in the world knowing that they would wind up in human bodies and, you know, continue to produce them long after they discovered they were in human blood and drinking water all over the world.

One of the places that we know in this country that are particularly contaminated are on military bases because of firefighting foam that was used.

Laurel, we spoke with some people who were at Camp Lejeune, which had apparently widespread contamination from the 50s to the 80s.

And I want to play a little bit from two people we spoke with.

The first person you'll hear from is Denis McClure... Denise McClure.

Her husband, Terry, was a Marine there and he died.

He had Parkinson's.

The second person you'll hear from is Norman Stites.

His son was born on Camp Lejeune and died at age nine of very serious complications.

Norman himself had multiple types of cancer.

Both of these individuals believe it is from the contamination and they are part of a lawsuit against the U.S.

military.

Let's listen to what they had to say.

He one day went to the doctor, had to get a pacemaker immediately.

Um... Next time he had skin cancer.

Then they said it was dementia.

Then they realized that it was Parkinson's.

He went from being my husband, I went from being his wife to he really didn't know I was his wife and I was his caregiver.

One thing that had happened, it's one thing to be betrayed and covering it up to me is betrayal.

And how many millions of people who went through Camp Lejeune.

You poisoned us.

That's it.

Brangham: Laurel, the... A lot of these communities, including the one featured in Mariah's book, came to a settlement with these companies.

And sometimes it provided them with access to better drinking water or cleanup of a certain site.

But medical monitoring, as I know something you have argued, is critical in some of these settlements.

Explain what that is and why it's important.

So the idea behind medical monitoring is that there are a lot of health effects that we know are linked to PFAS exposures.

And in communities that have had these high exposures, they know they can't change the past.

But moving forward, they see opportunities for information about those exposures to improve their healthcare and their clinical outcomes in the future.

And so the idea of medical monitoring for PFAS really came out of the C8 study.

So this was a study that was conducted in West Virginia.

And for anyone who's seen the film "Dark Waters," you'll know that this is a community that was contaminated by a DuPont plant.

And there was a large settlement against DuPont because of the contamination of this area by PFOA, which is also called C8.

And as part of the settlement, the settlement funded a major health study and much of what we learned about PFOA early on came from this large epidemiological study.

70,000 people in this community took part in this health study.

And through that health study, there was a determination of six health outcomes that were linked to PFOA exposure, including kidney and testicular cancer and elevated blood pressure during pregnancy or preeclampsia.

And so for people who had these health conditions, there were... there was support through the settlement.

And the settlement identified the need for medical monitoring for people who'd been exposed to PFOA through the drinking water, with the idea being that there are certain tests for conditions or biomarkers of effects that doctors can undertake to identify people who might've had high exposures and to have an early lookout for the types of health effects that might be related to those past exposures.

And it's really important for clinicians to be aware of the types of health effects linked to PFAS exposures to improve their care.

So the idea of medical monitoring is conducting screenings, not just for PFOA, but for other communities that have had elevated PFAS exposures.

There was a groundbreaking study in 2022 from the National Academies of Sciences, Engineering and Medicine, focused on these questions around clinician education, awareness and steps that clinicians can take.

And one important recommendation from this report was to recommend that people who have had high exposures potentially to PFAS and want to know about their exposures should get their blood tested or have access to blood testing so they can learn about their exposures.

And the report also had a series of recommendations for certain health screenings that they considered to be appropriate for people who'd had elevated exposures, with the idea being to improve clinical care and health outcomes in the longer run.

Brangham: Right.

Blake: I'd just like to note, so the NASEM report that she just mentioned, I think it's not only people with high levels of exposure because they recommend certain types of screening for people with between two and 20 parts per billion.

Now, the average American has more than two parts per billion in their blood.

So certain health effects, things like reduced vaccine response are seen at ordinary population levels of exposure.

And I think just the other thing I'd like to point out in terms of medical monitoring, in West Virginia, this was something that people were able to get through litigation, but the majority of states don't recognize medical monitoring as a cause of action.

So people cannot sue to get medical monitoring in a lot of states.

And there is now a law before Congress that's intended to change that one.

There was at least, I'm not sure the status at the moment, but anyways.

So this is not something that is accessible... - To everyone.

- To everyone.

It's only accessible to people in a very small number of communities.

I want to ask you about the, Mariah, about the government's role here.

I remember from the first Trump administration, they were very eager and said they were going to crack down on PFAS and set limits and things like that.

The Biden administration put some very strict limits on the amount of PFAS that could be in municipal water supplies.

The second version of the Trump administration has dialed a lot of that back.

What is the status?

What is the federal government doing right now to protect us?

Well, so there were two very important things that happened during the Biden administration.

One, as you mentioned, was the setting of drinking water standards and specifically the EPA set standards for six types of PFAS in drinking water.

The Trump administration has rolled back four of those, but it has maintained the standard for the two best known and best studied.

So that's PFOA and PFOS or "PFOS."

Um... The other thing that happened under the Biden administration that was really key, and this is a little more technical, but it's very, very important.

Um... The two best known PFAS were designated hazardous substances.

And that means that under the law, those responsible for the pollution have to map the extent of the contamination and pay for cleanup.

And that is actually... The Trump administration has preserved that.

And it's even going to court to defend it at the moment.

So... Um... But there are other things that have happened under the Trump administration that make it more difficult to address PFAS contamination.

So... Um... And I think maybe the most striking example has to do with the EPA's Office of Research and Development.

So a lot of what we know about these chemicals comes from the EPA's Office of Research and Development, which the Trump administration has shuttered.

Uh... And in fact, the methods that are used to detect these chemicals in drinking water and soil were developed by this office.

And that work is not finished.

So there are a lot of types of PFAS that we don't have the technology to detect.

And I think I mentioned previously, scientists recently discovered that there's one type of molecule, one PFAS molecule in the environment that's more abundant than all others combined, but that really hadn't registered on the radar until a few years ago.

So our sense... We do not have a complete picture yet of the scope of PFAS contamination.

And we, without this agency operating, without the Office of Research and Development operating, that really inhibits our ability to tackle this problem.

Laurel, can I ask you a question for people who might be listening to this and thinking, "Oh my gosh, these chemicals are everywhere.

"They're in everything in my home.

"They're even in the dust particles behind my couch."?

How do you talk to people about risk?

How worried should people be?

Are there steps that people can take to protect themselves?

Sure, and I think it's, you mentioned earlier that people sort of expect that the government is protecting us from toxic chemicals.

And I think a lot of people are concerned and surprised to learn that the government does not do a good job of protecting us from toxic chemicals being in the food that we buy, the water that we drink, the things that we buy for our families.

So when I talk to people who are learning that there are toxic chemicals in our everyday environment, I try to focus on the things that we can do.

And there are some steps that we can take as individuals.

Given that we know that exposures to PFAS can cause all types of health harms, not just at high levels of exposure, but at levels consistent with the general population, I do think it makes sense for people to take steps in their daily lives to reduce exposures where they can.

There are some things that we can do, such as avoiding buying Teflon coated pans, skipping stain resistant or waterproof items where they're not needed.

The formulations of food packaging have changed, but our advice in the past has been to avoid microwave popcorn and other types of greaseproof food packaging, which might contain PFAS.

And to learn about the types of products people are surprised to learn that Glide dental floss is made of Teflon.

There are cosmetics with PFAS.

So there are some steps that we can take to avoid products containing PFAS.

But a huge challenge is that when you go to the store and you look at a product, it usually doesn't say on the label, "This product contains PFAS."

Brangham: Right, it must be quite impenetrable for people to be an educated consumer.

Blake: So there are... - I mean, I study PFAS every day and I still am in the dark as much as anyone else is in terms of which products contain PFAS because of a lack of transparency.

There are certain resources such as the Environmental Working Group's Skin Deep Database that help consumers navigate this, that gives consumers some information about which products contain these chemicals and which don't.

So there are limitations, but they do offer some guidance.

And just in like the last 30 seconds we have left, you can also filter your water as well.

Yeah, and I generally recommend that people filter their water with a system that is certified to remove PFAS.

And a simple under sink system is sufficient for most people.

And that is a very easy way to protect yourself and your family.

Last to you, Laurel, is there anything else you would advise people to do who want to protect themselves and their families?

About 30 seconds we have left.

So there are some steps that we can take, filtering water, doing our research online, trying to find products that are PFAS free, but really this is a systemic problem.

And so we also can take steps as consumers to let retailers know that we want products that don't contain PFAS.

While there's not a lot of progress being made at the federal level, there are a lot of states that are considering legislation that would ban PFAS in products.

So people can get involved with those types of efforts in their state.

Brangham: Great, great.

Laurel Schaider, Mariah Blake, thank you both so much for being here.

Wonderful conversation.

Thank you.

- Schaider: Thank you so much.

- Blake: Thank you.

Before we go, we would like to give you a quick glimpse up into the heavens.

We noted how PFAS chemicals helped usher in the age of space exploration.

Those innovations brought us some remarkable images recently.

From the International Space Station came this, a red and green Aurora glowing above Europe as particles from the sun light up in our atmosphere.

Or this captured by the James Webb Space Telescope, the Red Spider Nebula, which is a massive burst of glowing gas and dust created when a star dies.

Or this reflection nebula captured by the Hubble Space Telescope.

This is up in the Taurus constellation.

Or here we see our own Earth reflected on the solar panels of the Blue Ghost Lunar Lander.

In March, Blue Ghost became the first private spacecraft to successfully land on the moon.

NASA is working with private companies to build out a support system for manned missions to the moon.

The next step towards that goal, the Artemis II, where four astronauts will travel around the moon and back, going further into deep space than any humans have before.

They could launch as early as this month.

That is it for this episode of "Horizons."

Thank you so much for joining us.

You can find our program on YouTube and wherever you get your podcasts.

See you next week.

Announcer: Support for "Horizons" has been provided by Steve and Marilyn Kerman.

Additional support is provided by Friends of the NewsHour.

♪ This program was made possible by contributions to your PBS station from viewers like you.

Thank you.

♪ You're watching PBS.