It’s not all bad news for America, though. The cleanest cities weren't ranked, as many received the same score. But the Southeast came out the big winner, with Charleston, SC, a significant number of Florida cities, and Savannah, GA all feeling like a breath of fresh air. In the category of lowest year-round particle pollution, Prescott, AZ came in first. The sun may scorch Prescott's earth, but the air breathes clean. See the whole list of clean cities here.
Take a deep breath, relax, and thank all those people on bicycles for reducing pollution. And if you live in California -- well, try not to breathe too deep.
Here’s how the 10 most polluted cities stack up:
Highest Ozone Pollution
10. Phoenix-Mesa-Scottsdale, AZ
9. Las Vegas-Henderson, NV-AZ
8. Modesto-Merced, CA
7. Dallas-Fort Worth, TX-OK
6. Houston-The Woodlands, TX
5. Sacramento-Roseville, CA
4. Fresno-Madera, CA
3. Bakersfield, CA
2. Visalia-Porterville-Hanford, CA
1. Los Angeles-Long Beach, CA