Thursday, Sep. 29, 2011

2. Fresno, Calif.

Fresno may be known as the "Raisin Capital," but the city is also regularly near the top of air-pollution lists. Traffic congestion and industry contribute to the pollution problems throughout the city. More than 75,000 of the city's 900,000 people suffer from asthma, and another 25,000 suffer from chronic bronchitis.