- [Narrator] 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.

[upbeat music] - [Scott] This one we can handle pretty easily.

So Andrew, why don't you c'mere 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.

- [Scott] And he's skinny.

- [Andrew] He is pretty skinny.

- [Scott] 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 a higher pressure is these infections.

Alligators usually don't have infections.

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

Gen X 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 the PFAS manufacturing discharge in North Carolina.

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

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

[bird whooping] - [Scott] 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, not too much further than just its skin.

- [Man] I've both.

[water splashing] - [Scott] Quickly secure their jaws.

[tape rips] - [Man] Good.

- [Scott] 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.

Could imagine that if 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 growls] - [Man] Shh, shh.

You're so big, I know.

[woman laughing] - [Man in Background] Help me cut this line.

[soft instrumental music] - [Narrator] 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 hadn't healed and knowing that alligator's wounds normally heal very, very quickly, you know that there's something wrong, especially for a young alligator.

- [Narrator] Erin and PhD student MaKayla Foster want to compare the levels of PFAS in 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.

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

- [Narrator] 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 cumulating in the environment, upon cumulating in the environment, and then there forever.

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

- [Scott] Is certainly a thrill to be close to these extremely powerful and amazing animals.

- Here we go.

- [Woman] Bye, bud!

Miss you!

[water splashes]