Polluted air triggers burning ban

The Spokane Regional Clean Air Agency on Monday issued a stage 2 burning ban on the use of all wood heating devices, including certified stoves.

The “red” burn ban, the strongest action the agency takes, will be in effect at least until midday today.

A “yellow,” or stage 1, ban affects only noncertified stoves and fireplaces.

Air pollution levels were on the rise in the Spokane area Sunday night and Monday as cold air near the ground prevented mixing of the atmosphere.

The clean air agency reported an air quality index well into the moderately polluted range from fine particles of smoke. A reading of 88 was reported Monday morning, well above the threshold of 50 for moderate pollution. The highest level was at a measuring station at Augusta Avenue and Fiske Street.

The ban affects all wood heating devices, including fireplaces, fireplace inserts and wood stoves. Outdoor burning was also banned. Exemptions are available for homes without other adequate heating systems and for lower income residents.

Monday’s 4 a.m. weather balloon measured warming temperatures to a height of about 900 feet above the ground, an indication that the pollution-trapping air inversion was fairly shallow.

In Spokane, 80 percent of winter air pollution is caused by wood smoke, which gets trapped by temperature inversions. The smoke is a health hazard because the aromatic compounds are so tiny they travel deep into the lungs and can be trapped there.

Light winds were allowing for some mixing of the air Monday afternoon, and pollution levels were dropping through the day.

But National Weather Service forecasters said a weather system off the Pacific would not be strong enough to end moderate pollution. A stronger system this weekend may finally clear the air, forecasters said.