"More than 127 million Americans -- about 41 percent of the country -- still suffer from pollution levels that can make breathing dangerous, according to a new report."

"The American Lung Association State of the Air 2012, released Wednesday, shows signs of air-quality improvement, but also indicates struggles in many regions nationwide. The volunteer health organization examined 2008-2010 ozone levels, the main ingredient of smog air pollution, and air-particle pollution at official measuring sites across the U.S.

Out of the 25 cities with the most ozone pollution, 22 saw improvements in air quality over last year's report. Similar advancements were seen among cities with the most year-round particle pollution."

Joanna Zelman reports for the Huffington Post April 14, 2012. [2]