Across the US, these 30 places have the worst air pollution

Air quality in the US has worsened the last three years. 24/7 Tempo used data from the Environmental Protection Agency to find the 30 metro areas with the highest air pollution levels.

30. New York-Newark-Jersey City, NY-NJ-PA
• Days with high PM2.5 pollution a year: 191
• Days with unhealthy levels of air pollution a year: 2
• High ozone days per year: 130
• Population: 20,192,042

26. Detroit-Warren-Dearborn, MI
• Days with high PM2.5 pollution a year: 191
• Days with unhealthy levels of air pollution a year: 2
• High ozone days per year: 79
• Population: 4,304,613

23. Stockton-Lodi, CA
• Days with high PM2.5 pollution a year: 204
• Days with unhealthy levels of air pollution a year: 10
• High ozone days per year: 154
• Population: 724,153

25. Modesto, CA
• Days with high PM2.5 pollution a year: 151
• Days with unhealthy levels of air pollution a year: 14
• High ozone days per year: 203
• Population: 535,684

24. St. Louis, MO-IL
• Days with high PM2.5 pollution a year: 210
• Days with unhealthy levels of air pollution a year: 2
• High ozone days per year: 129
• Population: 2,804,998

22. Yuba City, CA
• Days with high PM2.5 pollution a year: 198
• Days with unhealthy levels of air pollution a year: 7
• High ozone days per year: 166
• Population: 170,227

9. Hanford-Corcoran, CA
• Days with high PM2.5 pollution a year: 123
• Days with unhealthy levels of air pollution a year: 9
• High ozone days per year: 186
• Population: 150,183

21. El Paso, TX
• Days with high PM2.5 pollution a year: 147
• Days with unhealthy levels of air pollution a year: 2
• High ozone days per year: 190
• Population: 838,527

20. Philadelphia-Camden-Wilmington, PA-NJ-DE-MD
• Days with high PM2.5 pollution a year: 259
• Days with unhealthy levels of air pollution a year: 3
• High ozone days per year: 103
• Population: 6,065,644

19. Pittsburgh, PA
• Days with high PM2.5 pollution a year: 242
• Days with unhealthy levels of air pollution a year: 1
• High ozone days per year: 98
• Population: 2,348,143

Chicago-Naperville-Elgin, IL-IN-WI
• Days with high PM2.5 pollution a year: 205
• Days with unhealthy levels of air pollution a year: 6
• High ozone days per year: 112
• Population: 9,549,229

Las Cruces, NM
• Days with high PM2.5 pollution a year: 50
• Days with unhealthy levels of air pollution a year: 4
• High ozone days per year: 258
• Population: 213,849

Las Vegas-Henderson-Paradise, NV
• Days with high PM2.5 pollution a year: 76
• Days with unhealthy levels of air pollution a year: 1
• High ozone days per year: 226
• Population: 2,112,436

Sacramento–Roseville–Arden-Arcade, CA
• Days with high PM2.5 pollution a year: 117
• Days with unhealthy levels of air pollution a year: 16
• High ozone days per year: 246
• Population: 2,268,005

Madera, CA
• Days with high PM2.5 pollution a year: 120
• Days with unhealthy levels of air pollution a year: 5
• High ozone days per year: 210
• Population: 154,440

El Centro, CA
• Days with high PM2.5 pollution a year: 100
• Days with unhealthy levels of air pollution a year: 7
• High ozone days per year: 129
• Population: 179,957

Denver-Aurora-Lakewood, CO
• Days with high PM2.5 pollution a year: 56
• Days with unhealthy levels of air pollution a year: 8
• High ozone days per year: 232
• Population: 2,798,684

San Diego-Carlsbad, CA
• Days with high PM2.5 pollution a year: 162
• Days with unhealthy levels of air pollution a year: 0
• High ozone days per year: 202
• Population: 3,283,665

Payson, AZ
• Days with high PM2.5 pollution a year: 0
• Days with unhealthy levels of air pollution a year: 8
• High ozone days per year: 161
• Population: 53,145

Fresno, CA
• Days with high PM2.5 pollution a year: 121
• Days with unhealthy levels of air pollution a year: 19
• High ozone days per year: 231
• Population: 971,616

Los Angeles-Long Beach-Anaheim, CA
• Days with high PM2.5 pollution a year: 153
• Days with unhealthy levels of air pollution a year: 19
• High ozone days per year: 178
• Population: 13,261,538

Visalia-Porterville, CA
• Days with high PM2.5 pollution a year: 124
• Days with unhealthy levels of air pollution a year: 26
• High ozone days per year: 233
• Population: 458,809

Bakersfield, CA
• Days with high PM2.5 pollution a year: 106
• Days with unhealthy levels of air pollution a year: 27
• High ozone days per year: 246
• Population: 878,744

Riverside-San Bernardino-Ontario, CA
• Days with high PM2.5 pollution a year: 108
• Days with unhealthy levels of air pollution a year: 52
• High ozone days per year: 210
• Population: 4,476,222

San Francisco-Oakland-Hayward, CA
• Days with high PM2.5 pollution a year: 290
• Days with unhealthy levels of air pollution a year: 9
• High ozone days per year: 61
• Population: 4,641,820