Pittsburgh has the worst short-term particle pollution in the nation, surpassing Los Angeles in that category in the “State of the Air: 2008” report released in May by the New York-based American Lung Association (ALA). However, Los Angeles still has the highest level of year-round particle pollution and ozone pollution.

The report found that Los Angeles, Houston and other cities have made progress in reducing ozone levels, but others have fallen behind or stalled in their efforts. Four out of five Americans — 42 percent — live in counties with unhealthy levels of ozone or particle pollution, according to the report. ALA says stricter ozone standards recently adopted by the U.S. Environmental Protection Agency will help lower levels of the pollutant. The entire report is available at www.stateoftheair.org.

5 dirtiest cities for short-term particle pollution

  1. Pittsburgh
  2. Los Angeles
  3. Fresno, Calif.
  4. Bakersfield, Calif.
  5. Birmingham, Ala.

5 cleanest cities for short-term particle pollution

  1. Alexandria, La.
  2. Amarillo, Texas
  3. Bismarck, N.D.
  4. Brownsville, Texas
  5. Cheyenne, Wyo.