Feb. 1, 2007 -- A new study shows that air pollution can increase the chance of heart disease in women.

Below is the American Lung Association's 2006 list of the ten U.S. metropolitan areas most polluted by year-round particle pollution, or soot. Ties are listed with the same number.

1. Los Angeles-Long Beach-Riverside, Calif.
2. Bakersfield, Calif.
3. Pittsburgh-New Castle, Pa.
4. Visalia-Porterville, Calif.
5. Fresno-Madera, Calif.
6. Detroit-Warren-Flint, Mich.
7. Hanford-Corcoran, Calif.
8. Cleveland-Akron-Elyria, Ohio
9. Birmingham-Hoover-Cullman, Ala.
9. Atlanta-Sandy Springs-Gainesville, Ga.-Ala.