Nearly half of all Americans are breathing dirty air. That, according to a report from the American Lung Association.
As Rockford continues to grow so does the level of pollutants in the air. Last year Rockford was under an ozone alert during the summer heat. The county did receive a "B” grade but critics say that’s not as good as it seems.
The cities with the dirtiest air include Los Angeles, Fresno while Bellingham, Washington is the cleanest.