The American Lung Association鈥檚 annual is out, and it slots Greensboro as the 42nd most polluted metro area in the county.  The city received an F-rating.

Laura-Kate Bender, who worked on the report, says the news wasn鈥檛 all bad.

"Despite getting an 鈥楩,' the area actually got its lowest overall number of smog days," she says. "So even though it received a failing grade, it鈥檚 a significant improvement over last year."

Bender also says it鈥檚 important to remember that some air pollution drifts in from other states.

"When it comes to ozone pollution, or smog, that comes from industrial sources like power plants and from automobiles; Soot also comes from automobiles and industrial sources, but also comes from wood burning stoves and fires," she says.

Greensboro has two power plants, and its metro area includes Winston-Salem and High Point.

The looks at data from soot and smog pollution across the country. Charlotte ranked 19th in the most polluted metro areas in the U.S., while Raleigh-Durham was tied for 74th.

The Lung Association is encouraging people to download a so that they can check air quality levels every day.