There has been a lot of talk about air quality levels as nearly the entire tri-state area has been engulfed by smoke coming down from wildfires in Canada. But what do all the numbers actually mean?

Canadian wildfire smoke has diminished air quality across the Valley since Thursday. Here’s the index behind the health of ...

Smoke and ozone pollution have triggered air quality alerts across several states, raising risks for respiratory and heart ...

The Wisconsin Department of Natural Resources has issued a statewide air quality advisory for fine particle pollution, ...

Residents across central Florida woke this week to hazy skies and an urgent warning from air-quality officials: stay inside, close your windows, and avoid outdoor exertion. Fine particulate matter, ...