As wildfire smoke blankets the East Coast, Air Quality Index and PM2.5 numbers are everywhere. Here’s what they mean. Air Quality Index, or AQI, and PM2.5, particulate matter which measures 2.5 ...

Massive wildfires raging in eastern Canada are sending huge plumes of smoke across the border, blanketing thousands of square miles in the Northeastern U.S. and Upper Midwest, and casting a haze over ...

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?

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?