Most Smog

1. Los Angeles, California

2. Visalia-Porterville, California

3. Bakersfield, California

4. Fresno, California

5. Houston, Texas

6. Merced, California

7. Sacramento, California

8. Hanford, California

9. Knoxville, Tennessee

10. Dallas-Fort Worth, Texas

Most Particle Pollution

1. Los Angeles, California

2. Visalia-Porterville, California

3. Bakersfield, California

4. Fresno, California

5. Pittsburgh, Pennsylvania

6. Detroit, Michigan

7. Atlanta, Georgia

8. Cleveland, Ohio

9. Hanford, California

10. Birmingham, Alabama; and Cincinnati, Ohio.

Source: CNN.com – Lung association ranks most polluted cities