KNOXVILLE, Tenn. (WVLT) -- Knox Co. has earned a failing grade in year-round particle pollution, according to the American Lung Association's (ALA) latest "State of the Air" report.
Despite not passing, east Tennessee's most populous county still showed modest gains in ozone pollution levels and short-term particle pollution, each increasing a letter grade to a "D" and a "B," respectively.
"The air across Tennessee is certainly cleaner than when we started the 'State of the Air' report 14 years ago," noted Ellen Kershaw, the American Lung Association's Advocacy Director. "Even though unhealthy days of high ozone are still a problem, the air quality is still better than compared to a decade ago."
Blount and McMinn were among the nine counties that made the list of cleanest counties for short-term pollution, along with Davidson, Lawrence, Madison, Maury, Montgomery, Putnam, and Sumner.
The ALA described short-term pollution as particle pollution that can spike to dangerous levels for hours to weeks on end, while the long-term level is based on a daily average. It cited Ozone as the most widespread air pollutant. When inhaled, Ozone wil irritate the lungs and can cause wheezing, coughing, asthma, attacks, and premature death.
Nationwide, the ALA said more than 131.8 million people, or 42%, live in counties with unhealthy levels of Ozone or particle pollution.
Those numbers were still an improvement over the previous report, especially in the eastern United States, according to the ALA. It credited the gains, in part, to emissions reductions from coal-powered plants and cleaner diesel fuels and engines.
"The evidence is clear that the Clean Air Act delivers significant health benefits," said Kershaw. "Congress needs to continue to ensure that the provisions under the Clean Air Act are protected and are enforced. EPA and every state must have adequate funding to monitor and protect our citizens from air pollution."
The "State of the Air 2013" is the 14th annual report card produced by the ALA.