A single home that relies exclusively on wood for heat can emit as much particulate pollution as all the gas furnaces in a large Utah city. A romantic fire-lit evening can cost your neighbor up to $40 in medical expenses.
Air-quality advocates highlighted these and other new research findings Wednesday before the Utah Air Quality Board to urge members to consider year-round restrictions on wood burning in places where fine particulate matter is making the air unhealthy. Activists cited bans on trash burning as a precedent for clamping down on wood, but their bigger goal is to change public attitudes about fireplaces.
“Operating a vehicle with excessive emissions has long been prohibited through emissions inspections,” Carl Ingwell, of Clean Air Now, told the board. “We have accepted the rationale that even though it may be cheaper for the owner of an older, more polluting vehicle to continue to operate that vehicle, for the public good, those vehicles have to be cleaned up or retired. Why should home heating devices be any different?”
The Wasatch Front has long grappled with nasty air when winter inversions trap fine particulate matter, known as PM2.5, close to the ground, wrecking the views and making outdoor activity hazardous to health.
In Wasatch Front counties that are out of compliance with federal standards for particulate pollution, just 230 homes have registered as a residence where wood stoves are the primary source of heat. New research by University of Utah chemical engineer Kerry Kelly suggests these homes, restaurant grills and other sources of wood smoke are responsible for a disproportionate share of Utah’s air-quality problems.
“We know it is an issue for us and the more we learn about it the more we realize it needs to be addressed,” said Bryce Bird, director of the Division of Air Quality. Already under consideration is a rule that would require the removal of wood stoves as part of new real estate transactions.
A wood stove emits 50,000 to 100,000 times as much direct particulate as a gas furnace, and 60,000 to 250,000 times as much of the volatile organic compounds that act as particulate precursors, according to Kelly, who also serves on the Air Quality Board.
“Smoke from fireplaces, wood stoves and cooking grills was responsible for as much direct PM2.5 as vehicles when the PM2.5 was above 20 micrograms per cubic meter,” said Howie Garber, a member of Utah Physicians for a Healthy Environment (UPHE). “This further speaks to the inadequacy of the current burn program in controlling or minimizing the problem.”
Under current rules, wood burning is banned in the winter on red air quality days, although homes are exempt if solid fuels are the only source of heat. But UPHE president Brian Moench argued a big public health benefit can be achieved by keeping wood smoke out of the air even at times when the airshed is relatively clean.
He intends to pitch rules that would phase out wood stoves to government officials in Salt Lake City and in Utah counties with severe air-quality issues. His group recognized that it would be an economic hardship for some stove-dependent residences to install a cleaner heat source; Moench suggests subsidizing such conversions, which he figured would cost taxpayers around $2 million.
“That would be the cheapest air-quality mitigation program we could ever come with,” he said.
By the numbers
Kerry Kelly, a chemical engineer at the U., says her research shows that a wood stove emits 50,000 to 100,000 times as much direct particulate as a gas furnace, and 60,000 to 250,000 times as much of the volatile organic compounds that act as particulate precursors.