| Most polluted US cities (By short-term particle pollution) 1. Pittsburgh, Pennsylvania 2. Fresno, California 3. Bakersfield, California 4. Los Angeles, California. 5. Birmingham, Alabama 6. Salt Lake City, Utah 7. Sacramento, California 8. Logan, Utah 9. Chicago, Illinois 9. Detroit, Michigan | Most polluted US cities (By ozone pollution) 1. Los Angeles, California 2. Bakersfield, California 3. Visalia, California 4. Fresno, California 5. Houston, Texas 6. Sacramento, California. 7. Dallas-Fort Worth, Texas 8. Charlotte, North Carolina 9. Phoenix, Arizona 10. El Centro, California | Most polluted US cities (By year-round particle pollution) 1. Bakersfield, California 2. Pittsburgh, Pennsylvania 3. Los Angeles, California 4. Visalia, California 5. Birmingham, Alabama 6. Hanford, California 7. Fresno, California 8. Cincinnati, Ohio 9. Detroit, Michigan 10. Cleveland, Ohio |