Poor air quality caused by ozone and other sources prompted the warnings across six states on Thursday and Friday.

Smoking, air pollution and several other factors have led to significant disparities in lung health across the U.S.

DENVER — An unusual surge of dust blowing into Colorado this week is irritating eyes and sinuses across the state — even for ...

The dust hurts air quality not only by giving skies a milky haze, but also by aggravating respiratory problems and triggering ...