Knox County's air quality has received another failing grade, but the latest study shows the area is making improvements.
The American Lung Association's "State of the Air" report for 2013 came out Wednesday.
It gives Knox County a "D" for high ozone days and a "B" for days with 24-hour particle pollution, but it also notes that we saw fewer high ozone days than the year before.
Health officials say they're encouraged by the progress, and they hope everyone will continue to do what they can to reduce pollution.
"Taking care of your vehicles is probably one of the biggest things. When that check engine light comes on, take it in and get it fixed. Because when that light comes on, you're not operating your vehicle in a very efficient manner. That's one of the biggest things that we tell people. That and energy conservation," said Lynne Liddington, the Knox County Health Department Director of Air Quality Management.
The report also shows improvement in other east Tennessee counties.