Despite improvements in air quality in past decades, 156 million Americans still breathe in too much soot or ozone, says the ...

Several U.S. cities are experiencing heightened air pollution levels on Wednesday, including parts of Chicago.

A new report on air quality across the U.S. offers a cloudy prognosis on the long-term health of about 156 million residents ...

Almost half of everyone who lives in the United States breathes unhealthy levels of air pollution, according to the American Lung Association’s annual State of the Air report.