The LA area is once again the worst for ozone in the U.S., a pollutant impacting millions more people nationwide, the American Lung Association said.

The most recent State of the Air report by the American Lung Association found that more than 150 million Americans breathe air with unhealthy levels of ozone or particle pollution

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.