MARYVILLE, Tenn. (AP) — Data from a monitoring station in the Great Smoky Mountain National Park is part of an investigation into changing air quality.
The study is called the Southern Oxidant and Aerosol Study and it is funded by the Environmental Protection Agency. Scientists will examine how organic compounds and man-made emissions affect air quality by examining their atmospheric transformations and interactions.
Data from the Look Rock observation station is included.
Tennessee Valley Authority spokesman Duncan Mansfield said the station has been documenting significant reductions in haze and smog that parallel lower emissions from TVA's coal-fired power plants.
TVA environmental monitoring senior manager Dennis Yankee said since the 1970s, the utility has reduced sulfur levels by 94 percent and nitrogen levels by 90 percent in emissions from its power plants.
The Daily Times reported Jim Renfro, air quality specialist to the national park, said reduction of pollutants is widely beneficial.
"Emissions and climate go together, so that's going to define the air quality you have," Renfro said.
The Chattanooga Times Free Press quoted Renfro as saying the natural blue haze the Smokies were named for is more visible and the whitish pollutants aren't as evident.
"It's getting back to its natural state. It used to be, this time of year, the mountains would be gone in the haze. Now that's the exception," Renfro said.
The mountain air isn't crystal clear, however. Suspended particulates remain a problem.
The EPA defines particulates as a complex mixture of extremely small particles and liquid droplets made up of a number of components, including acids, organic chemicals, metals, and soil or dust particles.
TVA atmospheric scientist Steve Mueller said the particulates can affect people's health as well as dim the view from the mountains.
"We are trying to understand where they come from and how they are formed," Mueller said.
TVA continues to cut back on sources of pollution. An agreement the utility signed with EPA in 2011 requires it to close at least 18 of the 59 coal-fired generating units by 2018. The first two, at the John Sevier Fossil Plant, were retired in December and replaced by a cleaner natural gas plant.