So the agency added a disclaimer above the map: “Windblown ash particles may be too large to be detected by air quality ...

Dust and ash left behind from the January wildfires in Los Angeles County can be irritating and hazardous to health when it’s ...

Toxic smoke and dangerous particulate pollution are spreading far beyond the flames, leaving air quality at unhealthy levels ...

The Air Quality Index measured 156 near Forks, Washington, and received a rating of "unhealthy," meaning some members of the ...

This measure, based on data from the Environmental Protection Agency, evaluates states on the number of days the Air Quality Index in counties was not rated “good.” U.S. News calculated a ...

Calculating air pollution from wildfires and other events has become more complicated. That doesn’t mean it’s necessarily ...

The Air Quality Index, set by the Environmental Protection Agency, is your guide to how bad the air quality is outdoors. The data that goes into the Air Quality Index comes from 5,000 air monitors ...