Air quality alerts are in effect in the Philadelphia area, fueled by smoke from wildfires that are burning thousands of miles away.

Air quality has taken a serious hit across the United States as a two-fold blow of wildfires in the West and in Canada have sent smoke pouring across large sections of the country — a problem that’s set to linger for days.

Hundreds of wildfires still burning in Canada are expected to undermine air quality across the Upper Midwest and Northeast into Tuesday.