Want the Dirt on US Cities With Worst Air Pollution?

(April 29) -- If you're looking for a U.S. city or town with clean air, you might want to avoid Los Angeles, Phoenix and Bakersfield, Calif., a new study concludes.

The findings come from the American Lung Association in the form of its just-released ranking of U.S. cities by air quality. The study data, which was compiled by the Environmental Protection Agency from 2006 to 2008, shows that 58 percent of Americans live with air that is often unsafe to breathe.

The study examined three kinds of air pollution -- ozone, year-round particle pollution and short-term particle pollution -- and ranked American cities and towns by how they rated in each category. While ozone and short-term particulates can spike on any given day, long-term particulates remain a more consistent air hazard over time.

"Overall, we saw a big drop in levels of long-term particulates, which we attribute to tighter power plant controls," Janice Nolen, the ALA's assistant vice president for national policy and advocacy, told AOL News. "We still have a long way to go, however."

Ozone

When it comes to ozone, a pollutant that is especially harmful to children with asthma, California cities and towns were among the worst. One reason is that ozone levels spike in warmer climates, and can be exacerbated by geography like that of Los Angeles, where the eastern mountains tend to trap the city's pollution. The country's worst ozone offenders are:

1. Los Angeles/Long Beach/Riverside, Calif.
2. Bakersfield, Calif.
3. Visalia-Porterville, Calif.
4. Fresno and Madera, Calif.
5. Sacramento/Arden/Arcade/Yuba City, Calif.
6. Hanford/Corcoran, Calif.
7. Houston/Baytown/Huntsville, Texas
8. San Diego/Carlsbad/San Marcos, Calif.
9. San Luis Obispo/Paso Robles, Calif.
10. Charlotte/Salisbury/Gastonia, N.C.

Year-Round Particle Pollution

Living near a freeway or a soot-spewing power plant provides exposure to year-round particle pollution. According to the ALA, this category represents the greatest danger to human health; fortunately, it has also seen the biggest improvement in recent years, thanks to regulatory oversight. Yet it's still a considerable problem in the following areas:

1. Phoenix/Mesa/Scottsdale, Ariz.
2. Bakersfield, Calif.
3. (tie) Los Angeles/Long Beach/Riverside, Calif.
3. Visalia/Porterville, Calif.
5. Pittsburgh/New Castle, Pa.
6. Fresno/Madera, Calif.
7. Birmingham/Hoover-Cullman, Ala.
8. Hanford/Corcoran, Calif.
9. (tie) Cincinnati, Ohio/Middletown, Ky./Wilmington, Ind.
9. St. Louis, Mo./St. Charles, Ill./Farmington, Ill.

Short-Term Particle Pollution

Defined as spikes of particulate matter in the air that can last for hours or days, short-term particle pollution includes such things as toxic spills and one-off fires. As with long-term particle pollution, these bursts of tainted air can prove deadly. The cities with the worst levels of this pollution are:

1. Bakersfield, Calif.
2. Fresno/Madera, Calif.
3. Pittsburgh-New Castle, Pa.
4. Los Angeles/Long Beach/Riverside, Calif.
5. Birmingham/Hoover-Cullman, Ala.
6. Sacramento/Arden/Arcade/Yuba City, Calif.
7. Salt Lake City/Ogden/Clearfield, Utah
8. Visalia/Porterville, Calif.
9. Modesto, Calif.
10. Hanford/Corcoran, Calif.