In 2008 , the American Lung Association ranked the Pittsburgh area as the nation 's third most polluted metropolitan area , behind Los Angeles and Bakersfield , CA .
Pittsburgh has been ranked third in the country for most polluted cities by the American Lung Association .
Pittsburgh has been ranked third in the country for most polluted cities by the American Lung Association .
文章を簡単にしましょう: In 2008 , the American Lung Association ranked the Pittsburgh area as the nation 's third most polluted metropolitan area , behind Los Angeles and Bakersfield , CA . 出力: