The Los Angeles-Long Beach metropolitan area had the worst ozone pollution in the nation between 2015 and 2017, and also ranked among the worst in terms of particle pollution, or soot, according to an American Lung Assn. report released today.

Los Angeles-Long Beach has been ranked the worst area in the nation for ozone pollution for 19 of the 20 years the association has produced the annual “State of the Air” report. The region ranked seventh-worst in the nation for unhealthy particle pollution days between 2015-17, and fifth worst for annual particle pollution.

According to the report, the average number of unhealthy ozone days increased in Los Angeles-Long Beach in this year’s report, compared with last year’s. The same was true for 16 other cities listed among those with the worst ozone pollution in the country, including New York, Chicago, San Diego and Denver.

Authors of the report wrote that the document “adds to the evidence that a changing climate is making it harder to protect human health.”


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“The three years covered in this report ranked as the hottest years on record globally,” according to the report. “High ozone days and spikes in particle pollution zoomed, putting millions more people at risk and adding challenges to the work cities are doing across the nation to clean up.”

The report estimated that 43.3% of the American population lives in counties with unhealthy ozone and/or particle pollution levels. It also found that 141.1 million people were exposed to unhealthy air during the study period, up from 133.9 million in last year’s report and 125 million in 2017’s document.

“More must be done to address climate change and to protect communities from the growing risks to public health,” according to the report.


“This year’s report covered the three warmest years in modern history and demonstrates the increased risk of harm from air pollution that comes despite other protective measures being in place.

“The Clean Air Act must remain intact and enforced to enable the nation to continue to protect all Americans from the dangers of air pollution.”