10 Most Polluted US Cities California is a familiar presence By Newser Editors, Newser Staff Posted Apr 30, 2015 7:07 PM CDT 34 comments Comments The Los Angeles skyline is obscured by a heavy layer of smog in this file photo. (AP Photo/Jerome T. Nakagawa, File) (Newser) – The American Lung Association is out with new rankings of the cities worst hit by air pollution, and Los Angeles sits atop it. The report looks at both particle and ozone pollution, reports Time. The top 10 in the latter camp: Los Angeles-Long Beach, Calif. Visalia-Porterville-Hanford, Calif. Bakersfield, Calif. Fresno-Madera, Calif. Sacramento-Roseville, Calif. Houston-The Woodlands, Texas Dallas-Fort Worth, Texas Modesto-Merced, Calif. Las Vegas-Henderson, Nev.-Ariz. Phoenix-Mesa-Scottsdale, Ariz. The ALA is calling for tougher air-quality rules. Failing that, you might check out these six urban areas, which registered zero days of ozone or particle pollution for an entire year: Bismarck, ND; Cape Coral-Fort Myers-Naples, Fla.; Elmira-Corning, NY; Fargo-Wahpeton, ND-Minn.; Rapid City-Spearfish, SD; and Salinas, Calif. Click to read the full report.