OLYMPIA - The state Department of Ecology has issued Stage 1 burn bans in Okanogan, Douglas, Chelan and Kittitas counties, effective immediately.
The bans will continue until further notice, the agency said. Smoke builds up where cold air is trapped near the ground and can cause breathing and heart problems.
Children, people with asthma and respiratory illnesses, and adults older than 65 are most at risk from wood smoke, Ecology said.
A Stage 1 ban applies to the use of uncertified wood-burning devices - including wood stoves, inserts and fireplaces - and all outdoor burning.
The use of uncertified wood-burning devices is prohibited unless they are a home's only adequate source of heat. Uncertified units typically were built before 1990 and lack a certification label.
Burn ban violators are subject to civil penalties.
The bans do not apply on tribal reservations, where the U.S. Environmental Protection Agency has jurisdiction. That agency has issued a burn ban for the Yakama Indian Reservation; the Colville reservation is not affected.