A national park battles pollution

The Great Smoky Mountains National Park bordering North Carolina and Tennessee is not only a natural paradise but also is home to 20,000 species of animals and plants. However, that park has some of the highest measured air pollution and the highest level of acid rain of any national park in the country.


Great Smoky Mountains National Park, bordering North Carolina and Tennessee, is not only a natural paradise, but also is home to 20,000 species of animals and plants.

However, the park has some of the highest-measured air pollution and the highest level of acid rain of any national park in the country.

Here's the story.

[ Birds chirping ]

Great Smoky Mountains National Park is a biologic treasure trove.

[ Water flowing ] More than 20,000 species of animals and plants are identified in the park.

And what's important for researchers is the long history of observation that documents all of that life.

The Smokies have a rich history of being studied by people for over 100 years now.

This place had early descriptions from people that explored the area.

We have botanical records of people coming here and describing species for the first time.

We also have great sets of data on weather and water quality that enable us to look at impacts over a long-term data set.

The information is a valuable research tool to understand just how the park is changing.

The trouble is, the data shows one of the greatest threats to the park is from the air.

And all of these things cannot simply be protected by drawing a line around the Smokies and then saying that, once you cross this line, it is now protected from all harm, because so many challenges have now presented themselves that move across that line, some of which is coming through our air.

I mean, you learn about the threats that we have to so many different species from air quality.

In fact, Great Smoky Mountains National Park experiences some of the highest-measured air pollution of any national park in the country.

It also receives the highest level of acid deposition from acid rain and acid fog of any park.

And it's all because of the park's location.

It's downwind of many sources of air pollution, including power plants, factories, and vehicles.

In fact, the emissions from the eastern 2/3s of the nation affect the air over the Great Smokies.

That air pollution contributes to the decline of old-growth forests.

Ground-level ozone harms plants.

The acid rain increases the acid content in the soil, which blocks plant nutrients and releases other toxic chemicals.

The acid rain also changes the chemistry in streams, which affects forest health and kills aquatic vegetation as well as fish.

But what is most visible to park goers is how pollution, combined with fine particles in the air, creates haze.

Scenic vistas that should be seen for almost 113 miles are now only visible for about 25.

But, if the skies seem dark and dirty, the researcher in charge of monitoring the park's air quality does see a bit of blue sky.

The good news is it can recover.


So there's hope.

Jim Renfro is standing in a small forest clearing that's been transformed into a science station.

It's one of seven air-quality monitoring stations in the park.

So, we monitor mercury, part of a national network, just like the acid rain program.

And this is, like, a wet and dry collector.

So, when it does rain, it's only measuring mercury through this chimney.

There's a glass funnel, a little tube into a collection bottle.

And so when it rains, that rain is gonna hit this sensor over here, and I'll just fake like it's raining.

And it should move this arm over and expose the wet side -- the side that we want to collect on.

Right now, this is the dry side.

It's not raining.

It's waiting for rain.

Here comes the rain, and it's going to activate this motor and expose what we call the wet side.

And so the rain gets in there, is collecting.

There's a similar device nearby to measure all the chemicals that fall from the sky, especially those that create acid rain.

So, we're measuring nitrogen and sulfur, and then all the good stuff -- so, we get all the elementals, like calcium and magnesium and potassium.

So, we're measuring the acids, but some of the stuff that's also in the air.

The weather station also collects more common weather data, such as temperature, humidity, wind speeds, and precipitation.

Additional instruments monitor ozone and fine particles in the air -- that stuff that creates haze.

So, when utilities put on controls, we're gonna be able to measure those improvements.

And we are.

So, I'm going to fake like it's drying out now and it's stopped raining.

I'm going to blow the water off of that, and that arm should go back over.

[ Blows ] So, the rain event stopped, and we're going to protect that sample from contamination.

The data from all of that monitoring has helped scientists understand the effects of pollution on the forest.

But the information has also been used in a public-awareness campaign, and that has led to stricter air-pollution controls.

[ Water flowing ]

That has had a huge impact on improving all the things that we just talked about -- visibility, haze, ozone levels, acid rain are all better since the late 1990s.

So, about 15 years of steady improvement and progress.

Researchers report the air in Great Smoky Mountains National Park is getting cleaner.

That means visitors can see a few more miles.

We're improving faster than just about anywhere else in the United States because we're downwind of where a lot of the emissions are -- the Ohio Valley, the Tennessee Valley.

The Southern-tier states that affect us have made significant progress toward reducing emissions that create the pollutants that blow downwind.

For almost 20 years, the park was non-attainment for ozone, meaning we had measured violations -- We had measured hundreds of days where the air was unhealthy to breathe in some place in the park.

Right now, the entire park is designated attainment -- meaning we're meeting the standards, all the air-quality standards -- and now we want to stay there.