Applying air quality results for cleaner air

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.

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

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.

To read about some of the impacts of air pollution on Smokies streams, go to Dispatches Issue 3: Stream Acidification and Partner Profile: Taking the pulse of Smoky Mountain streams.

Return to Dispatches from the Field: Issue 5 main page.

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