The new report evaluated air quality in different parts of the country by measuring the presence of ozone and particle pollution in the atmosphere.

Air in the U.S. has gotten cleaner for decades, adding years to people's lives and preventing millions of asthma attacks, but nearly half of Americans still live with unhealthy air pollution, a new ...

Smog from wildfires sweeping the nation has left tens of millions more Americans to breathe toxic air even as man-made forms of pollution fall, according to a new study released Wednesday. The ...