Millions More Americans Suffering from Harmful Air, Report Says

More than two million additional Americans were affected by unhealthy particulate matter and ozone pollution than last year, according to the American Lung Association’s new air quality report released Thursday.

The annual State of the Air report said more than 137 million people living in the U.S., or 40%, are exposed to unhealthy levels of ozone and particulate matter pollution, which over time can cause serious illness and death.

• This report—which used EPA data to measure the last three years of air quality in the U.S.—registered more days of “very unhealthy” and “hazardous” air quality than at any time since ...