Pittsburgh surpasses Los Angeles as nation's sootiest city

In this July 2, 2003 file photo, the skyline of Pittsburgh is seen through the morning haze from across the Allegeheny River. A city outside California has for the first time been named the sootiest in the nation, one of the categories the American Lung Association uses to determine the most polluted cities in the country. Pittsburgh overtook Los Angeles in the category that measures short-term particle pollution or soot. Los Angeles still took the all-around pollution title. (AP Photo/Keith Srakocic)