Air pollution levels keep getting worse for more people in the US, according to a new report, and experts say the Trump administration’s proposed deregulation plans will make it even harder for people to get clean air.

Despite improvements in air quality in past decades, 156 million Americans still breathe in too much soot or ozone, says the annual State of the Air report from the American Lung Association.

Denver's ozone pollution ranks among the worst in the U.S., according to a report out Wednesday from the American Lung Association. Why it matters: Air pollution threatens everyone's health — especially children,