In Pictures: America's 10 Dirtiest Cities

Half of America’s 10 dirtiest cities, listed by particle pollution as measured by the American Lung Association in its 2005 report, are located in California. If measured by smog, all but two are located in that state. Los Angeles
The area of Long Beach and Riverside takes the top prize for the most polluted zone in the U.S.–an area of frightful traffic and heavy industrial emissions that has the bad luck of air inversions that hold the bad particles right where they hurt. Visalia-Porterville, Calif. The strip cities of Visalia-Porterville can thank a good deal of their particle problem on Route 99, with being located in a valley with hot, motionless air doesn’t help either. Bakersfield, Calif.
In addition to Route 99, which it shares with Visalia, Bakersfield has Interstate 5 to compound the particle problem: lots of traffic, valley heat and air inversion. Fresno, Calif.
It may be north of Bakersfield and Visalia, but Fresno is almost in a league with them in particle count and ozone. It has an organization called 1,000 Friends of Fresno, who are working to improve their city’s air quality. Pittsburgh
The cities of Pittsburgh and Newcastle count on the winds from Ohio and West Virginia to bear the majority of their fine particles away, but the city’s industries, as well as the major highways like Route 79, still contribute to poor air quality.

Interesting shit. Reason number 18790830 Cali sucks. Detroit
Detroit not only has a bad count in short-term particles but an undistinguished record in water pollution and other health hazards. The good news is that particle count appears to be improving. However, Motor City is built around cars and not public transportation, and the improvement doesn’t look like it’s moving very fast. Atlanta
All too many roads lead to Georgia, as General Sherman knew. The traffic density and emissions are aggravated by sulfur-spewing plants like Bowen. The burning of Atlanta goes on. Cleveland
Cleveland’s pollution problem is very much a regional issue, as it is close to many industrial pollution sources. It also has a serious smog problem that is to some extent a highway (Route 90 for instance) as opposed to a smoke stack problem. Hanford, Calif.
Hanford-Corcoran is close to Visalia and shares its fine particle pollution from some of the same factors (highways, valley and heat). It is also faced with big problems in smog production. Birmingham, Ala.
Birmingham sits at the confluence of many Interstates and that, along with emissions from industry and utilities, has made particles a challenge for the city. They are doing better in the ozone department.