- Hi there.

I'm Frank Graff.

PFAS chemicals made life easier, but we now know they're toxic.

What's next when it comes to PFAS?

And see how pollution is affecting a unique salamander.

It's all coming up on "Sci NC."

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[subtle inquisitive music] [subtle inquisitive music continues] - Hi again and welcome to "Sci NC."

PFAS chemicals are found all around us and that's not surprising.

The United States Environmental Protection Agency lists almost 15,000 manmade chemicals that fall under the title of PFAS.

They have been used in industrial, commercial, and consumer products for almost 70 years.

Producer Rossie Izlar went along with researchers tracking what we know about the toxic compounds.

- [Rossie] This is Greenfield Lake.

It's in the heart of Wilmington, surrounded by neighborhoods and busy city streets.

So it might be surprising to know that Greenfield Lake is home to lots of alligators.

And today, scientists from NC State are reeling them in to see how they're doing.

- This one we can handle pretty easily.

So, Andrew, why don't you come here a second.

We know where the hooks are 'cause those are what's gonna hurt us now at this point.

He is, he's got a lot of these open wounds here.

- [Andrew] Mm-hmm.

A lot of little ones.

- He's skinny.

- He is pretty skinny.

- He's not very healthy.

So if you wanted to come in here, these are some of the phenotypes that we've noticed here with the higher pressure is these infections, alligators usually don't have infections.

- [Rossie] The animals and people living in the Cape Fear River watershed are still haunted by GenX, a pollutant that a chemical manufacturing company released in the water for decades.

GenX is part of the PFAS family, a group of chemicals that scientists are sounding the alarm on.

They're called forever chemicals because they don't break down in the environment and they are in tons of consumer products from Teflon pans to waterproof boots to makeup.

The alligators at Greenfield Lake are downriver from the plant that manufactured and released those chemicals for years, and that's why Scott and his team are checking on them.

- We're looking at levels of PFAS and looking to see if there's any health effects on the alligators.

Alligators are a really great model for us.

They have immune system that's very similar to humans.

They've been in the water now since the beginning of PFAS manufacture and discharge in North Carolina.

And we think that's a really good historical model to look at for potential health effects.

- [Rossie] But before you can examine a gator, you need to catch one.

[alligator chirps] - Essentially, we take a big fish hook and we cast across the animal, usually bring it into shore with the hook kind of catching, you know, not too much further than just its skin.

I have both.

Quickly secure their jaws.

He's got stuff in his mouth.

Good.

We can take a blood sample and then have them released usually within 10 or 15 minutes.

One of the key things that we do is actually minimize the stress.

So we work very quickly.

You could imagine that if an an animal is caught in a trap, that could really increase the stress of being restrained and all of this.

So we try to avoid that.

[alligator growling] Oh, shush.

You're so big.

I know.

[researcher laughs] Help me cut this line.

- [Rossie] Side note, that's me in the blue shirt trying to figure out if I should be worried that the alligator seems to be coming towards me.

It all worked out.

Alligator blood can tell scientists how much PFAS chemicals are in the water and how gators are responding to them.

And so far things don't look great.

- I think one of the scariest things for me was seeing the really young juvenile alligator where he had wounds that can't heal.

And knowing that alligators wounds normally heal very, very quickly, you know that there's something wrong, especially for a young alligator.

- [Rossie] Erin and PhD student MaKayla Foster want to compare the levels of PFAS in the alligators at Greenfield Lake to the Gators at Lake Waccamaw, a more rural lake that isn't directly downstream from the chemical company.

- And so we're seeing much higher levels in the alligators that are near the point source, as we would expect.

- [Dr. Belcher] The animals at our exposed sites are in poorer condition than those that have the actually much lower exposure, the ones at Lake Waccamaw.

- [Rossie] Of course, it's not just alligators that are reacting to PFAS exposure.

These chemicals are ubiquitous in the U.S.

Most of us have it in our bloodstream.

Researchers found that exposure to PFAS can put people at risk for an array of health problems, including: cancer, thyroid diseases, and immune disorders.

- Some people, I think, are still pretty unaware of the presence of PFAS around.

So our goal is just to keep showing what we're finding and make people more aware of what's out there because the more aware they are, the more chances there are for change.

- Ultimately, we're trying to weed out the bad actors, if you will.

There may be some in here that are perfectly safe and useful.

However, this idea of bioaccumulation and persistence is a hard one to get over.

We really don't want chemicals accumulating in the environment, upon accumulating an environment, upon cumulating in the environment, and then there forever.

- [Rossie] And in the meantime, Scott will continue checking on the alligators at Greenfield Lake.

- It is certainly a thrill to be close to these extremely powerful and amazing animals.

Here we go.

- Bye guys.

Thank you.

[water splashes] - [Announcer 2] You can watch more "Sci NC" episodes anytime on our website or through the PBS streaming app.

- Previous research has shown that 95% of Americans have some detectable levels of PFAS in their blood.

After testing hundreds of water systems around the nation, the U.S. Geological Survey reports almost half of the tap water in the nation shows some amount of PFAS.

In April, federal officials established the first nationwide drinking water standards for two types of PFAS compounds.

That's April of 2024.

Producer Evan Howell shows us how utilities are working to meet the standards.

[bright music] - Hey, where'd all the oily lotion go?

- [Evan] Remember how simple life was thanks to your favorite products?

- Fabulous!

- [Evan] And how things were just better thanks to new and improved ways to do basically everything.

- Oh, there's no question about it.

Ted has the softer diaper.

[Ted coos] - [Evan] But if it seems too good to be true, you might wonder how we got here.

[subdued music] Thank the chemists.

For a lot of these products, we can thank the developing of PFAS.

You may not know PFAS, but PFAS knows you and it's everywhere, including inside you.

This is important because we now know that PFAS can create health problems like cancer.

PFAS is short for per- and polyfluoroalkyl substances.

They're called forever chemicals and they've been developed over decades, they go into things like non-stick Teflon pans, fabrics, furniture, and even makeup.

Another big problem is PFAS is in our drinking water.

So how do we get rid of them?

[dour music] We've been purifying water for millennia and it was only up until 1804 when the first municipal water treatment plant was built in Scotland.

There, they use sand.

Some operations still use sand, but there are other methods as well.

But the problem with PFAS is that they're created with some of the strongest bonds in chemistry so they don't break down.

Over the years, PFAS has seeped into the ecosystem, our food supply and our water supply.

And cities and towns are always on the lookout for solutions.

- This is like the world's largest Brita filter.

- [Evan] Brita filters, like you may see in your kitchen, use granular activated carbon, or GAC, and it's a common way used by commercial operations to reduce PFAS levels today.

In fact, the Sweeney Water Treatment Plant in Wilmington installed eight giant GAC beds in 2022.

- What happens is as the water flows over the granular activated carbon, PFAS sticks to the surface.

It has a lot of surface area and that's why one of the reasons it's very good at removing PFAS.

- [Evan] Data from recent studies by several government agencies show that GAC removes PFAS from water, but the findings from the studies differ on how much PFAS is taken out.

- Which we developed at UNC.

- Okay.

Since there are a number of ways to purify water, Sweeney recently invited Professor Frank Leibfarth to test yet another method inside their plant.

- The the real like change in philosophy we took is all resins previously were developed to take all the junk out of water that is typically in water, right?

There's organic matter, there's ions, this is all stuff you don't want to drink, and those were kind of, you know, catchall solutions that would be thrown at every new contaminant.

But PFAS is different because PFAS is dangerous at incredibly small amounts.

- [Evan] The Environmental Protection Agency started investigating PFAS as far back as 1998.

And up until then there had been a patchwork of regulations that emerged as more scientists discovered what was going on.

But by 2024, the EPA set its first-ever limits on PFAS in drinking water to their lowest levels in history.

- This is a drop of water in five Olympic-sized swimming pools.

- [Evan] In 2017, Leibfarth was at a faculty meeting and was asked if he knew a way to get rid of them all.

He was a new father then and knew that something called a hydrogel made diapers work.

- A hydrogel takes water, right, out of out of materials and I actually just had a son recently, so we were using a lot of diapers, right, and diapers are amazingly efficient at absorbing water.

So I said like, what if a fluoro gel could absorb fluorous material in the same way?

And we really wanted to get it right before we started running it 'cause- - [Evan] Who knew diapers could inspire technology to get rid of PFAS?

PFAS are what are called fluorinated molecules, which is when a fluorine atom is bonded with a carbon atom, again, very strong and hard to get rid of.

Leibfarth and his team have come up with what they think is a promising solution.

It's called ion exchange.

The process is where these impurities are exchanged with ions of safer chemicals, usually sodium or potassium.

One of the big differences in their process is that their resins can be cleaned and used again where normally, a lot of GAC is landfilled after one use.

- Tell me what you're doing, Emily.

Ion exchange resins have a greater capacity for PFAS removal compared to granular activated carbon.

Meaning that they can remove more mass of PFAS per mass absorbent compared to granular activated carbon.

- [Evan] But just because it works in the lab, it means very little if you can't make it big enough to handle the water of a treatment plant like Sweeney.

And that's what they're doing here in their lab in Morrisville.

- Scale development.

So we're basically working out the formulation and just seeing which ones are the most effective.

And then we scale it up, so then we figure out what the ideal reaction conditions are and we optimize those conditions.

- Each of these columns contains a different material.

You know- - So back to the pilot.

Water coming into Sweeney is siphoned off through these tubes.

Two tubes hold versions of their resin and the others have water samples cleaned by traditional methods currently used at Sweeney and other water treatment plants.

Leibfarth says to get the best data possible, the pilot will run for about a year.

He says they got to this point by thinking outside the box and is excited about the results so far, but adds, no solution will ever be perfect since there's always more to discover.

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- So there's now a race to figure out, not only how to remove PFAS from the environment, but also how to destroy it.

Various means using other chemicals to make PFAS nontoxic are being tested.

I checked on another method being tested at the EPA's lab in Research Triangle Park.

[subdued music] This is a two-story-tall furnace with a big name.

- So this system here is a down-fired thermal oxidizer.

- [Frank] And that big furnace with the big name has one job: burn up dangerous chemicals.

- It basically simulates an industrial process for destroying hazardous or difficult-to-destroy compounds.

- [Frank] Those dangerous and hard-to-destroy compounds are PFAS, per- and polyfluoroalkyl substances.

They're called forever chemicals because they last forever.

The secret is in the chemistry.

- PFAS have the common attribute of having a carbon-fluorine bond and that bond is the strongest possible bond that carbon can have.

And so to break that bond you have to have tremendous energy and frequently that energy comes in the form of heat.

And that's exactly what we're studying here.

We're applying tremendous energy to the PFAS chemicals in the form of heat to break the bonds.

- That super-strong carbon-fluorine bond is what made PFAS chemicals so useful.

They made life better and that's why they're found everywhere: waterproofing, non-stick surfaces, firefighting foam.

Let's focus on that foam a little more.

- So this here is a small sample of aqueous film-forming foam and it's basically a liquid mixture of concentrated PFAS molecules mixed with water and then sprayed on.

And it foams so much that it actually coats the fire and prevents oxygen from reaching the fire.

So this is an example of a perfluorobutanoic acid and it's one example molecule that would be found in many AFFF or aqueous film-forming foam mixtures.

- [Frank] Trouble is, those really useful chemicals are also toxic.

PFAS chemicals have been linked to multiple health issues including cancer.

And those molecular bonds that made PFAS chemicals so useful are also what keep them from breaking down in the environment.

Remember that forever chemical nickname?

PFAS chemicals have been found in everything from the water supply to us.

It's a chemical conundrum, toxic mixtures found everywhere, not breaking down.

The challenge is how to destroy them and that's where the rainbow furnace comes in.

- [Jonathan] We're trying to understand what conditions result in full destruction of all of the fluorine contained in it.

- [Frank] Temperatures in the furnace range from 1,000 to 2,000 degrees Fahrenheit.

Different color levels, different temperatures.

- Our burner is up top and as you come down from the burner it gets cooler.

And so in these ports in the side we have these high-temperature thermocouples that we use to continuously measure the temperature in each zone.

- [Frank] Researchers are learning what temperatures and conditions are best for destroying PFAS.

- We use this dual-fluid atomizer and basically this gets introduced into a port on the side of the rainbow furnace.

And out of the tip here, we spray a mist of AFFF or other PFAS-containing liquid.

So we can very precisely determine how much of the liquid we're injecting.

In order to know, you know, ascribe a number like 99.9% destruction, you have to know exactly how much entered the system.

[subdued music] So in incineration we like to talk about the three Ts.

It's time, temperature, and turbulence.

You basically have to have enough time for everything to come up to temperature.

You have to have enough turbulence for everything to sufficiently mix and actually reach the temperature.

And then you have to have everything reach whatever the required temperature is to break all the carbon-fluorine bonds.

If any of those three attributes are insufficient, you can end up with products of incomplete destruction, which are essentially fragments of the original PFAS molecule that you started with.

- [Frank] Those PFAS chemicals that aren't destroyed could be as toxic as the original compounds.

- I like to think of it as like a Lego set.

If you build a big Lego set, you know what that is, and then, but if you come along and hit it with a sledgehammer or a bunch of heat, it breaks up into a bunch of pieces.

You might not recognize it as the set that you built, but you're still gonna recognize it as a bunch of Lego bits.

- [Frank] And there's also a concern about the gases that are released during incineration.

That smoke or vapor could also be toxic.

Scientists capture it for testing.

- And those samples would be pulled into these canisters, whatever's in the stack or in the emission source would come out into this can.

Then we'd bring them over to a lab and they can be analyzed with gas chromatography, which separates those gases out according to their, you know, physical and chemical properties.

- [Frank] Researchers hope their work will provide guidance on how to destroy large quantities of PFAS chemicals.

- PFAS are in a lot of different things, in a lot of different materials and can come off of those in a lot of different ways.

So we're trying to answer that question of how do you measure it and, and where is it?

You know, we're doing the research part of it.

You know, we have communities that are interested in knowing whether they're safe or not.

We have states and local agencies that are clamoring to know what they need to do to keep their citizens safe.

And then we have our partners here in the federal agency that are gonna look at what policies need to be set, what guidelines, what rules or regulations, and also our information will feed into all of that.

- [Announcer 2] Check out our weekly science blog to take a deeper dive on current science topics.

- So how do scientists know just how polluted a river is?

Well, one way is to test the water.

The other way is to see what is living in the water.

And that is where the Neuse River water dog comes in.

This unique salamander used to be found all along the Neuse and Tar Rivers.

Development changed that.

But now, scientists are surveying the river to find out just where the water dog is thriving, to figure out how to save it.

[gentle bright music] - They're adorable.

They're now a threatened species, but they're endemic to North Carolina and the Neuse River and it's something that not everyone has gotten to see before.

- There's a lot of excitement when we pull up the trap and there's one in there.

Not just because, "Oh my God, I'm seeing this awesome creature," but because this is a threatened species.

So when we see one, it's just all the more exciting because, "Wow, it's around."

- [Frank] It only lives in sections of the Neuse and Tar Rivers and their tributaries that are in rural, wooded areas.

You won't find it anywhere else in the world.

But when it's found, it's considered... - I think they're really charismatic.

- I think they're charismatic.

- Once you see them, they're very charismatic.

- [Eric] What was the code again?

It's a male going into the breeding season.

So if you translate that to water temp, it's like 18 Celsius.

- [Frank] It is the Neuse River water dog salamander.

Yep, those red gills fluttering in the water, the tiny legs, and what appears to be a smiling face, all make for a charismatic creature.

It's also a threatened species.

- Salamanders, because they have really permeable skin, and they spend a lot of time, or at least portions of their life around the water, they're really affected by things like water quality.

And so if the water quality in a particular area begins to degrade, they're going to be one of the first species to respond to that 'cause they'll take in whatever toxins, whatever pollutants are in the environment and that'll negatively affect their health.

- [Frank] Neuse River water dogs have been studied on and off for the past 50 years.

- [Eric] 38 grams.

- [Frank] Eric Teitsworth is the third generation of scientists to pick up the study.

- [Eric] When we actually catch a water dog, we are taking some basic measurements, things like length, weight, we're also marking them and taking photographs so that if we were to recapture an animal we would know.

And recapturing animals gives us some information towards knowing how healthy the population is, how many individuals are actually out there.

We're also taking tissue samples so that we know how populations are connected to one another within their potential range.

And sort of more broadly, out from just what information are we getting from each salamander, we're also trying to get information on the habitat where we're catching them.

You know, what's different from this place where we've just caught two individuals versus somewhere like the main stem of the Neuse River in Raleigh where we're just not able to catch them anymore.

Is there something that's important about the habitat that's being reflected in where and where these things do and do not occur?

- Looking at this, I'm thinking moving water, pretty sheltered, there's a tree there.

This would probably be pretty decent habitat, I would think.

- Absolutely.

Yeah.

This is great habitat.

This is kind of what you're looking for.

A place with a nice flowing current.

You have lots of structure inside the streams, like I was mentioning before, where you have sticks and logs, some leaf packs over here.

Places where the water dogs can both hide as they're growing.

But then also you have places where they're able to lay their eggs and that's crucially important, we think.

Photos 77 and 78.

[gentle music] - [Frank] The charismatic salamander is not only a threatened species, it's also what scientists call an indicator species.

It is sensitive to changes in the environment and when there's a disruption, it's one of the first species to disappear.

- Even if someone may not care about a salamander, if you think about it, they are very indicative of water quality.

So that's the stuff you're playing in, your kids are playing in, you might be drinking it.

And if they're declining due to something going wrong in the water, what does that say about the water quality around here?

- [Frank] Water dogs spend their entire life in the water.

They can live for 20 years.

- It's sort of this accumulation of stressors, environmental contaminants that can cause damage and sort of affect reproduction, affect all of these things.

We're finding that they're not found in a lot of the locations that they were previously found, where there's now a lot of, again, what we call stressors.

So things that are coming into the water system, runoff, or all of these other things that could influence the water quality.

- [Frank] The project is monitoring 40 traps and while there's more study to be done, [water sloshing] one of their early findings is that heavy water runoff from urban areas poses one of the biggest threats to the Neuse River water dog.

- [Krishna] The flow, the rate at which water is coming down in the stream or river, is really important for water dogs and for a lot of species.

So if we have a whole bunch of trees, a whole bunch of natural environment, the water that's running off from, say from a road or just from rainfall, is kind of trickling into the system, right?

It's not causing some huge push of sedimentation and all these other things.

But once that area gets developed, we get this huge increase and there's all of this water that can come flushing down the system and that can have a really negative effect on species.

- [Frank] That fast-moving water either scours the stream bed or buries it in silt.

- So the U.S.

Fish and Wildlife Service has developed a recovery outline, which we'll then use as a template for recovery planning.

[bright music] And we need to reduce threats.

That's probably the biggest thing that humans can help do besides protecting land, is reducing threats.

And so that means reducing sediment going into the streams, it means reducing the nutrients that go in the streams.

- Environments that have been more disturbed by like development or maybe, you know, excessive runoff going into the stream, that tends to wash out or even bury all of this structure in the stream that water dogs really need to survive.

And when it's just becomes that sort of desolate, sandy environment where there's much fewer places to hide, that seems like what's really the problem here.

- Want more "Sci NC?"

You can find these stories and more on our YouTube channel.

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And that's it for "Sci NC" for this week.

If you want more "Sci NC," be sure to follow us online.

I'm Frank Graff.

Thanks for watching.

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