The state has issued an air quality advisory for the Fairbanks area through Saturday.
The Fairbanks Daily News-Miner reports cold air and temperature inversions are behind the poor air quality.
The advisory from the state Department of Environmental Conservation covers Fairbanks, North Pole and surrounding areas.
It also deems the air quality in Fairbanks as “unhealthy,” the third-worst category behind “very unhealthy” and “hazardous.”
People with respiratory or heart disease, the elderly and children should avoid prolonged exertion. Others should limit any prolonged exertion.