(CNN)More Americans are breathing air that will make them sick, according to the American Lung Association's annual State of the Air report.
The new report says that 141.1 million Americans -- 4 in 10 -- live in counties that have air with unhealthy levels of particle pollution or ozone. That's an increase of 7.2 million people from last year's report. Wednesday's report, the organization's 20th, looks at data on particle pollution and ozone pollution from 2015 to 2017.
Eight city areas had recorded the highest number of days with unhealthy spikes in particle pollution since the American Lung Association started monitoring pollution this way: Fairbanks, Alaska; Missoula, Montana; Bismarck, North Dakota, Bend-Pineville, Oregon; Yakima and the Spokane-Spokane Valley-Coeur d'Alene area in Washington; and Salinas and Santa Maria-Santa Barbara, California.
An increasing number -- more than 20.5 million people -- lived in counties with year-round particle pollution problems. Topping that list was the Fresno-Madera-Hanford, California, area; followed by Bakersfield, California; Fairbanks, Alaska; Visalia, California; Los Angeles-Long Beach, California; San Jose-San Francisco-Oakland, California; the Pittsburgh-New Castle Weirton, Pennsylvania-Ohio-West Virginia area; El Centro, California; the Cleveland-Akron-Canton, Ohio, area; and Medford-Grants Pass, Oregon.
"California is getting better, but it is still a problem and is still is at the top of our lists," Nolen said.
Wildfires are also a big source of air pollution and are becoming a bigger problem with climate change. Notably, the large wildfires of 2018 aren't included in this data, said Nolen, who has worked on State of the Air every year for the past 20 years.
"We've made great strides cleaning up some of the sources [of pollution]. We have much cleaner vehicles, power plants are doing better, but a lot of this is challenged by the current administration's rollbacks and with climate change, because we have such extreme weather patterns of drought and wildfire and that can add to particle pollution," Nolen said.
"We are seeing the impact of climate change now. Something has to be done," Nolen said.
There are some cities in the report that the American Lung Association thinks are getting it right. Only six qualify as "cleanest," meaning they have no high ozone or high-particle-pollution days and rank among the 25 cities with the lowest year-round particle pollution. They are Bangor, Maine; Burlington-South Burlington, Vermont; Honolulu, Hawaii; Lincoln-Beatrice, Nebraska; Palm Bay-Melbourne-Titusville, Florida; and Wilmington, North Carolina.