Pittsburgh tops polluted city list
Pittsburgh achieved a historic first as it surged ahead of Los Angeles in the category of "short-term particle pollution" or soot. This was the first instance of a city outside California winning the sootiest city title in an annual report by the American Lung Association.
LA is still the winner of the all-around pollution title.
Los Angeles, the country's longtime soot and smog leader, has enacted aggressive measures to tackle sources of pollution, resulting in a substantial drop in particle pollution levels, said Janice Nolen, the association's assistant vice president of national policy and advocacy.
"It's not that Pittsburgh has gotten worse; it's that Los Angeles has gotten better," Nolen said. "If the trend continues, Pittsburgh will top two lists, and LA will only be leading the nation in ozone."
Still, Los Angeles held its own in two other categories measuring year-round soot levels and smog. And statewide, 26 of California's 52 counties with air quality monitoring stations got failing grades for having either high ozone days or particle pollution days.
The following eight made it to the rather inglorious list of most polluted US cities.
The eight metropolitan areas considered to be the nation's most polluted by every measure were Los Angeles, Bakersfield, Fresno, Visalia-Porterfield and Hanford-Corcoran, all in California; Washington-Baltimore; St. Louis; and Birmingham, Ala.