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.

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.

A new report on air quality across the U.S. offers a cloudy prognosis on the long-term health of about 156 million residents who live in areas that received an "F" in smog and soot pollution.