MEDFORD, Ore. (AP) - Officials have issued an air stagnation advisory for much of south central Oregon through Friday afternoon.
The Oregon Department of Environmental Quality issued the alert Wednesday based on information from the National Weather Service.
The advisory includes Grants Pass, Cave Junction, Medford, Ashland, Altamont, Klamath Falls, Beatty, Bly, Chemult, Crescent, Gilchrist and Sprague River.
Forecasters expect an inversion over these areas, conditions which include light winds and limited mixing in the air. During an inversion, smoke can be trapped at ground level where people breathe.
Officials ask people in the affected areas to limit outdoor burning and the use of uncertified woodstoves.
Scientific studies have linked smoke pollution to problems including coughing, aggravated asthma, bronchitis and irregular heartbeat.