5.No. 7: San Diego, CA
The San Diego-Chula Vista-Carlsbad metro area scored an F on this year’s ozone report, with more than 100 days of high readings. The toxic air is bad news for the metro area’s more than 300,000 kids and adults with some form of asthma.
6.No. 6: Sacramento, CA
The Sacramento Valley is shaped like a bowl. In summer, pollutants like exhaust from cars get trapped closer to the ground. The Sacramento-Roseville metro area, home to 2.6 million, earned a spot on the lists for highest ozone days, most unhealthy spikes in particle pollution, and annual particle pollution levels.
