Meet the Managers: Air Quality Monitoring

A clear view from Cove Mountain.

A clear view from Cove Mountain.

NPS photo.

There are seven main Resource Management programs in Great Smoky Mountains National Park: Air Quality, Cultural Resources, Fire, Fisheries, Inventory and Monitoring, Vegetation, and Wildlife.

When you gaze off of a summit at Great Smoky Mountains National Park, what do you see? On a clear day, you may see rolling hills unfurled like blue and purple ribbons reaching all the way to the horizon. Or, on the same cloudless day, you may see a whitish haze that blurs far away mountains. Air pollution—the source of haze—not only obscures views, but can cause public health problems and makes the Smokies’ streams and soil acidic, as well. We need a long-term air quality program to understand what causes pollution, what pollution does to ecosystems (and visitors), and what we can do to reduce it.
Look Rock air quality monitoring tower.

Russell Paulk hoists a sensor high in the air after changing its filters at the Look Rock station.

NPS photo.

What is air quality monitoring? All around the park, from mountaintop to valley, are air quality monitoring stations that take continuous readings of air temperature, humidity, visibility, ozone, and acid rain. With the help of water quality monitoring research that measures high elevation sulfate and nitrogen deposition, air quality monitors can describe the current air conditions and long-term trends in air quality. This is invaluable information for managers, scientists, and local, state, and federal governments that use the data to regulate air pollution.

Who monitors the park’s air quality? Atmospheric scientists, meteorologists, climatologists, ecologists, biologists, and engineers monitor the amount of pollution in the air (and soil and water), as well as the impact of pollution on living systems in the park, including plant leaves, soil organisms, and stream life. To read more about air quality monitoring in the park, go to the NPS Profile: Air above & beyond the Smokies.

Excellent visibility at 150 miles.

On an excellent visibility day in the Smokies, you can see over 150 miles.

NPS photo.

Understanding Air Pollution

The problem of air pollution is worldwide. It results from humans burning fossil fuels and sources of carbon, including coal, oil, gasoline, shale, and wood. In the Smokies, most of our air pollution comes from human activities outside the park.

Read more about pollution, including ozone and the sulfur, nitrogen, carbon, and mercury that come from burning fossil fuels, then use the back arrow on your browser to return to this page.

Our air quality program grew throughout the 1980s to become the full-fledged monitoring program that it is today. In the late 1970s and early 1980s, national parks were just starting to take part in the new National Acid Deposition Program (NADP). All along the Appalachian range—from the southern end in the Smokies to its northern reaches in New York’s Adirondack mountains, people could see the problems of acid rain killing fish in remote lakes and eating away stone structures and statues.

Average summer visibility is 17 miles.

We rarely see the views shown above; on an average summer day, poor air quality restricts the view to 17 miles.

NPS photo.

To understand just what was happening in protected areas, the Smokies began monitoring how much air pollution is coming into the park at high and low elevations, and what impacts the air pollution had on plants, soil, and streams, and animals.

With the beginning of these programs, the Smokies became an example for other national parks. Soon many had their own air quality monitoring programs. Now, parks across the country monitor not only acid deposition (nitrogen and sulfur deposited in wet and dry form) but also weather conditions, visibility, ozone, fine particles, and mercury.

From their long-term monitoring, scientists could tell that the Great Smoky Mountains were receiving very high levels of acids and other pollutants. Their next step was to figure out how to make air clean again. That turns out to be a very big job.

State of Tennessee Clean Air TN banner.

The Tennessee Department of Environment and Conservation works for clean air.

TDEC photo.

Collaborating with Researchers

The problem of air pollution isn’t limited to the skies over Class I areas such as Great Smoky Mountains National Park, and neither is solving it. Many governmental, non-profit, and educational groups are involved with the park's efforts to monitor air quality. These include the Environmental Protection Agency, the National Oceanic and Atmospheric Association, the Tennessee Valley Authority, state governments of North Carolina and Tennessee, and local air programs such as Knox County Air Pollution Control and environmental groups.

A USGS project collects falling leaves, which will be tested for mercury.

A USGS project collects falling leaves in the park. Researchers will test the leaves for mercury, which the leaves can absorb from polluted air.

NPS photo.

Academic researchers, including PhD students and their professors, are vital collaborators. They conduct research on air pollution and air quality, including these past and ongoing permitted research projects:

  • Acid deposition impacts on streams, aquatic life, bird productivity, and Frasier fir and red spruce trees
  • Hiker health, air quality, traffic congestion, and emissions
  • IMPROVE visibility modeling to measure how particles of pollution scatter light
  • Inventory and Assessment of Night Sky Quality: how dark is it?
  • Lichen inventory and monitoring
  • Look Rock Supersite—monitoring of many air quality measures at high elevations
  • Mercury in precipitation, and its impacts on the park's biota
  • Modeling acid deposition levels across the mountainous park
  • Nitrogen studies: how levels vary and how it impacts spruce-fir forests
  • Ozone damage on cutleaf coneflowers, tall milkweed, wildflowers, and eastern hardwood forests
Jim Renfro inside the Look Rock monitoring station.

Jim Renfro, who began work at the Smokies in the 1980s, at the Look Rock monitoring station.

NPS photo.

Applying Air Quality Results for Better Air

The Air Quality Act of 1967 was only the first of many legal steps to protect clean air. In the decades that have followed, many federal and state laws, as well as the knowledge gained from park monitoring and research, have led to cleaner air:


  • Clean Air Act, and an amendment giving large parks “Class 1” special protection
  • High blood lead levels in 88% of U.S. children
  • Phase-out of leaded gasoline


  • Smokies Air Quality program begins
  • Look Rock & Elkmont air monitoring stations installed
  • IMPROVE program begins to monitor disappearing views due to haze in 156 national parks
  • Cove Mountain air quality monitoring station built, followed by Clingmans Dome & Noland Divide
  • Integrated Forest Study to link air pollution and vegetation damage
  • IMPROVE sites established in 20 national parks
One of four IMPROVE air filters at Look Rock.

One of four IMPROVE air filters at Look Rock.

NPS photo.


  • Large-scale study of ground level ozone injuries to plants conducted by NPS & Environmental Protection Agency (EPA)


  • Amendments to Clean Air Act focus on sulfur & nitrogen pollution: goals include reducing acid rain & reducing future emissions
  • Southern Appalachian Mountains Initiative: regional plan to improve air quality
  • Percent of U.S. children with high blood lead levels drops to 4%
  • Regional Haze Rule announced to improve visibility on haziest days & ensure no additional hazy days occur in Class 1 areas (including large national parks)
  • Reduced carbon monoxide, sulfur dioxide, lead, & particulate matter in air
  • Clean Smokestacks Act signed in North Carolina to cut power plant emissions
  • CAIR: Clean Air Interstate Rule caps sulfur dioxide (SO2) and nitrogen oxides (NOX) in eastern U.S.
  • State of North Carolina sues EPA for not enough protection/enforcement in CAIR
  • EPA begins drafting new rule while leaving CAIR in place for the time being


  • EPA's Clean Power Plan to lower greenhouse gas emissions
  • Tighter ozone pollution standard issued by EPA to protect public health and welfare

Although pollution has decreased, the total amount of acid deposition continues to exceed levels that are healthy for plants and animals. For a healthy park, we hope to see continued reductions in pollution.

Temperature and wind sensors at Cove Mountain.

Temperature and wind sensors at Cove Mountain.

NPS photo.

Did You Know?