New report rankes the cleanest and most polluted U.S. cities

U.S. Nearly half of U.S. kids are breathing unhealthy air, report says. These are the cleanest and most polluted cities. By Emily Mae Czachor Emily Mae Czachor News Editor Emily Mae Czachor is a reporter and news editor at CBSNews.com. She typically covers breaking news, extreme weather and issues involving social justice. Emily Mae previously wrote for outlets like the Los Angeles Times, BuzzFeed and Newsweek. Read Full Bio Emily Mae Czachor Updated on: April 22, 2026 / 2:00 PM EDT / CBS News Add CBS News on Google For 152 million Americans, including nearly half of the nation's children and teens, just breathing air in the places they live can be harmful. According to the American Lung Association's latest State of the Air report, 44% of the U.S. population reside in areas with unhealthy levels of pollution, including 33 million who are younger than 18.Experts have warned for years that kids are particularly susceptible to the consequences of pollution exposure. Young people are deemed more vulnerable because they have developing lungs, relatively large air consumption needs compared with adults and spend more time outdoors."We recognize that there's a connection between air pollution and exposure in children and chronic diseases," said Kevin Stewart, the director of environmental health at the American Lung Association and one of the report's co-authors. "The problems aren't necessarily immediate, in terms of just sending a child with asthma to the hospital. It also can affect the induction of asthma in children who ordinarily wouldn't have gotten it, or reduce lung function over their lifetime because they've been exposed as children."The new report evaluated air quality in different parts of the country by measuring the presence of ozone and particle pollution in the atmosphere, over short-term and longer periods of time. Ozone pollution is also known as smog; particle pollution is known as soot.Counties were graded based on how much smog and soot the rese...