Air pollution tied to lung cancer in non-smokers

Air pollution tied to lung cancer in non-smokers
http://www.nlm.nih.gov/medlineplus/news/fullstory_118102.html

"People who have never smoked, but who live in areas with higher air pollution levels, are roughly 20 percent more likely to die from lung cancer than people who live with cleaner air, researchers conclude in a new study."