More people across the United States – nearly 40% – are living in places with unhealthy levels of polluted air, according to a new report from the American Lung Association.
The number of people living with levels of air pollution that can significantly affect their health climbed from about 119 million in last year’s data to 131 million in the current data, according to the “State of the Air” report released Wednesday.
Extreme heat, drought and wildfires are among the factors that have contributed to a rise in deadly air pollution, especially in the Western part of the country, said Katherine Pruitt, author of the report and senior director of the American Lung Association’s Nationwide Clean Air Policy.
“The air pollution produced by wildfire smoke is getting worse every year,” Pruitt said. “Climate change is contributing to that situation, and those wildfires are a very serious threat to our health.”
In 1970, President Richard Nixon signed the Clean Air Act into law, and since then, emissions of outdoor air pollutants have dropped 78%, according to the US Environmental Protection Agency.
“But there still are way too many people breathing unhealthy air,” Pruitt said, adding that since the American Lung Association launched its annual “State of the Air” report in 2000, she has seen a shift in air pollution becoming a growing problem in the West.
“Our cars are cleaner. Our fuels are cleaner. Most of the dirtiest coal-fired power plants have fortunately been shut down, and industry is cleaner. So that’s cleaned up a lot of the traditional sources of pollution in the East, in the more industrial parts of the Upper Midwest and the Northeast. That same cleanup has been done in Western states as well, but at the same time, the Western states have been growing rapidly,” Pruitt said.
“The amount of oil and gas extraction that happens in the West has increased, which produces a lot of emissions,” she said. “And they are suffering, first, from the impacts of climate change and wildfire. So a lot of that geographic shift you’re seeing, particularly with particle pollution, is related to wildfire smoke.”
‘A real serious concern’
Researchers from the American Lung Association analyzed EPA data on air quality throughout the United States. They examined hourly ozone concentrations on average and the daily average of particle pollution from 2020 to 2022. The researchers used the EPA’s updated national air quality standard for year-round levels of fine particle pollution.
The American Lung Association then gave US counties “grades” for ozone and two measures of particle pollution.
According to the new report, the 10 cities most polluted by year-round particle pollution were:
• Bakersfield, California
• Visalia, California
• Fresno-Madera-Hanford, California
• Eugene-Springfield, Oregon
• San Jose-San Francisco-Oakland, California
• Los Angeles-Long Beach, California
• Sacramento-Roseville, California
• Medford-Grants Pass, Oregon
• Phoenix-Mesa, Arizona
• Fairbanks, Alaska
Often hard to see, particulate matter or particle pollution is a mix of solid and liquid droplets that may come in the form of dirt, dust, soot or smoke. Coal- and natural gas-fired power plants create it, as do cars, agriculture, unpaved roads, construction sites and wildfires. Particle pollution is so tiny – 1/20th of a width of a human hair – that it can travel past your body’s usual defenses. Particle pollution is associated with an increased risk of death from cardiovascular disease, respiratory disease and lung cancer.
Using their analysis, the researchers gave US counties “grades” for their individual levels of air pollution – based on ozone and particle pollution – and found that 65 million people live in the 112 counties that earned an “F” grade for unhealthy spikes in particle pollution, representing an increase of 1.3 million people from last year’s report.
“That’s the sixth straight year of increases, and that’s a real serious concern. Particle pollution is really deadly,” Pruitt said. “We also see not only more people in more places affected, but the level of particle pollution that they’re breathing is worse than it’s ever been.”
Also, more than 100 million people live in counties with F grades for ozone smog, according to the report. Ozone pollution is the main ingredient in smog. It is formed from emissions from many sources, including cars, power plants and refineries. Exposure to ozone can exacerbate asthma symptoms, and people with long-term exposure to higher levels face a higher risk of death from respiratory diseases than those who live with cleaner air.
According to the new report, the 10 cities most polluted by ozone were:
• Los Angeles-Long Beach, California
• Visalia, California
• Bakersfield, California
• Fresno-Madera-Hanford, California
• Phoenix-Mesa, Arizona
• Denver-Aurora, Colorado
• Sacramento-Roseville, California
• San Diego-Chula Vista-Carlsbad, California
• Salt Lake City-Provo-Orem, Utah
• Houston-The Woodlands, Texas
The report notes that many cities in the United States have air that is considered “clean” for one or more of the pollution measures tracked in the data, but only five of those cities ranked “clean” across all measures for particle pollution and ozone: Bangor, Maine; Johnson City-Kingsport-Bristol, Tennessee; Lincoln-Beatrice, Nebraska; urban Honolulu, Hawaii; and Wilmington, North Carolina.
“We have seen impressive progress in cleaning up air pollution over the last 25 years, thanks in large part to the Clean Air Act. However, when we started this report, our team never imagined that 25 years in the future, more than 130 million people would still be breathing unhealthy air,” Harold Wimmer, president and CEO of the American Lung Association, said in a news release.
“Climate change is causing more dangerous air pollution. Every day that there are unhealthy levels of ozone or particle pollution means that someone – a child, grandparent, uncle or mother – struggles to breathe,” he said. “We must do more to ensure everyone has clean air.”
Broad efforts are needed
The new report highlights the critical impact that air pollution has on public health, with an emphasis on ozone, but ranking cities based on air pollution may not be that helpful because it requires broader state, national and global efforts to tackle air pollution, said Tarik Benmarhnia, an air pollution and wildfire researcher at the University of California, San Diego, who did not work on the new report.
“Ozone is extremely difficult to intervene on. Once it’s there, it’s too late. But what we can eventually do of course is reduce the precursors, which at the end of the day would be very beneficial – reducing emission from traffic, for example,” Benmarhnia said, adding that some communities have been more affected by ozone air pollution than others.
“While we are not all equal and some communities may need way more investment in terms of air pollution abatement – because the potential benefits could be substantial as opposed to other communities – I think it would be interesting in the future to try to come up with some metrics that emphasize how proportionate efforts can be implemented to try to reduce inequities that are directly attributable to air pollution,” he said.
The new report highlights how air pollution in the United States disproportionately affects Black and brown communities.
Although people of color make up about 42% of the US population, according to the report, they represent 52% of people living in a county with at least one failing grade for air pollution. In the counties with the worst air quality, 63% of the nearly 44 million residents total are people of color.
The new report shows that the United States still has “a huge air pollution issue” to tackle, says Lina Mu, an epidemiologist and associate professor at the University at Buffalo School of Public Health and Health Professions.
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“Breathing the unhealthy air will cause tremendous health consequences, in particular for vulnerable populations such as pregnant women, fetuses, children, and people with asthma or heart diseases. The impact on the next generation can be very profound,” Mu, who was not involved in the new report, said in an email.
“It will certainly need policies from multiple levels to reduce the emission of pollutants, adopt stronger regulations and standards, and address climate changes to be effective in controlling air pollution levels,” she said. “Certainly, there needs to be more investment from federal and local governments to tackle air pollution issues.”
CNN’s Jen Christensen contributed to this report.
