Burn bans take effect as pollution risk rises

Cold, stable air over the Northwest has led to widespread burning bans.

National Weather Service forecasters said conditions that favor a buildup of pollution will continue through Friday and possibly into next week.

The weather service on Monday issued an air stagnation advisory for the Spokane and Coeur d’Alene areas through 4 p.m. Friday.

The Spokane Regional Clean Air Agency maintained its stage 1 partial burning ban Monday. Only federally certified wood stoves or fireplace inserts may be used during the ban.

Fireplaces and noncertified stoves are currently illegal to use. Outdoor burning is also banned in Spokane County.

The ban went into effect Saturday, and pollution levels have dropped as a result, said Ron Edgar, chief of technical service for the agency.

No violations of air quality standards occurred, he said.

Officials are asking residents to use clean sources of heat to minimize the health threat from a buildup of wood smoke in the air.

In North Idaho, the state Department of Environmental Quality banned all outdoor burning in Boundary, Bonner, Kootenai, Shoshone and Benewah counties. Idaho officials also asked residents to voluntarily curtail indoor burning.

Forecasts are calling for a mix of sun and clouds with highs in the middle 30s. Lows will be in the lower 20s as higher air pressure dominates the region.

Air pollution levels rise at night when temperatures drop and ease during daylight hours if the sun warms the air. Pollution has been trapped because temperatures at ground level are colder than aloft. Monday morning’s atmospheric profile showed that the temperature inversion reached about 3,000 feet above the ground.

The air quality index was at the low end of the moderate range for pollution Monday morning, then dropped into the good range as afternoon sunshine created conditions for vertical mixing of the air.

This week’s burn ban is the second this season. A stage 2 ban Nov. 7 and 8 prohibited burning even in certified stoves.

Burning bans have been relatively infrequent in recent years due to stormy fall and winter weather that prevented pollution from accumulating.

Air stagnation advisories were posted in several counties east of the Cascades as early as last week. Air quality has been poor throughout much of Washington and Oregon. Burn bans were widely in effect Monday in Washington.

Until Monday, Spokane and Coeur d’Alene had not been included in the air stagnation advisories.