Wood Stoves Light Up Clean Air Controversy
The outrage begins when the first blade of grass is torched every summer: grass burning be damned - it’s killing us all.
The rolling columns of stinging smoke give a Neanderthal air to a society that otherwise insists on catalytic converters and unleaded gasoline for its automobiles. The burning bluegrass prairie sends people with asthma, cystic fibrosis and other breathing problems to the emergency room.
However visible and offensive, grass burning isn’t the biggest miscreant when it comes to pumping particulates into the Inland Northwest’s air and residents’ lungs.
Wood-burning stoves are. Burn barrels also help make fall and winter a worse season for clean air than the annual field burning.
Residents of several communities holler about the Rathdrum Prairie, Spokane County and the Coeur d’Alene Reservation burning grass fields to regenerate them after the summer harvest. But people in those same towns just as eagerly put a match to their burn barrels, piles of leaves from the lawn, the organic garbage from the garden.
Post Falls alone has issued 1,531 outdoor burning permits this year - 300 of them since the grass burning season ended in late September. Another 220 people have secured permits for burn barrels in the River City in 1995.
Hayden, Coeur d’Alene and Kootenai County allow similar kinds of burning during all but the driest months of the year.
Only Spokane County holds back. It has restricted most open burning for 20 years.
Both grass smoke and wood smoke are notorious for their particulates. Carcinogens and other toxic compounds attach to those tiny particles, taking a free ride into people’s lungs.
“Wood-stove combustion can actually be worse for long-term health,” said Ron Edgar, chief of technical services for the Spokane County Air Pollution Control Authority. Wood stoves can be starved for oxygen, leading to incomplete combustion, and the emission of a wider variety of chemical compounds.
It’s like distilling the wood, not burning it, he said.
Michael McCarthy, the Spokane physician who runs the Inland Empire Cystic Fibrosis Clinic, doesn’t take the position that grass smoke is worse than wood smoke. But “I think wood smoke is a big problem - I don’t think there is any reason to target grass burning more than (wood burning),” Michael said. “My clinical impression is that they are both bad for kids with lung disease.”
Asthmatics have more problems when their family heats with wood, McCarthy said. Even in wood-heated houses where there are no asthmatics, children have more upper-respiratory infections and colds, he said.
Jane Koenig, a University of Washington professor studying Spokane’s air, says wood smoke contains some of the same constituents as tobacco. Since grass burning is uncommon outside of the region, less is known about its smoke. Still, she suspects an analysis of grass smoke would look much the same as wood and tobacco smoke.
Chronic exposure to wood smoke can be serious. Consider this example: Women in Nepal often spend their days inside poorly ventilated huts with wood fires while the men are outside. Even though the men smoke and the women don’t, the women show higher incidences of chronic bronchitis, Koenig said.
Spokane County regulates wood stove use and restricts burning on particularly bad days. Still, a 1990 study shows wood stoves contributed 19 percent of the particulates to the Spokane metropolitan area’s air quality problems. Industrial sources were 12 percent. Grass burning - which doesn’t occur in the general metropolitan area that is of concern to air quality watchers - is less than 1 percent, Edgar said.
Corresponding statistics won’t be available for North Idaho until early next year. But it’s easy to see a similar trend.
Grass burning on the Rathdrum Prairie generates an estimated 100 to 140 tons of particulates a year. Wood stoves in Sandpoint alone - the only area in North Idaho to legally regulate wood burning - pump out 97 tons of particulates a year, said Dan Redline of the Idaho Division of Environmental Quality.
So why doesn’t wood burning generate the same sort of outrage as grass burning? “People enjoy wood burning and do it voluntarily,” Koenig said.
Other experts speculate that wood smoke is noticed less because people aren’t outside as much in the winter - when wood burning hits its peak - and because the level of wood- burning pollutants builds up more slowly than the instant tornados of grass smoke. It’s also hard to shut down stoves when they are the sole source of heat.
Art Long, president of the Clean Air Coalition in Sandpoint and primary foe of grass field burning, says the comparison between grass and wood emissions are silly and the statistics are contrived.
Wood smoke is a concern for clean air activists, he insists. There was a wood-stove buy-out program in Sandpoint last year.
But Long also pushes the populist view.
“Wood stoves heat people’s homes - hundreds of people’s homes,” Long said. When it comes to grass burning, “25 (industry) people profit at the expense of thousands,” he said.
“This is an ornamental products industry,” Long said. “They aren’t growing food for the starving.”