L.A., Bakersfield remain among U.S.'s most polluted cities, report says
Wednesday, April 27, 2011 - 10:30
in Earth & Climate
American Lung Assn. says smog and soot levels dropped significantly in Southern California over the last decade, but the L.A. area remains the worst region in the nation for ozone pollution.Smog and soot levels have dropped significantly in Southern California over the last decade, but the Los Angeles region still has the highest levels of ozone nationwide, violating federal health standards an average of 137 days a year.