<i>By Robert McClure, InvestigateWest and Katie Campbell, EarthFix/KCTS 9

For the full article please visit NPR.org.</i>

The warning label on the wrapping of neatly split firewood is one we're more accustomed to seeing on cigarettes or heavy-duty chemicals: "known... to cause cancer, birth defects or reproductive harm."

But in fact, heart attacks, strokes, high blood pressure, asthma attacks and premature death – in addition to cancer – all are linked to wood smoke pollution. It's a finding that poses a vexing dilemma for poor and rural communities around the Northwest where wood is a cheap or even free source of heat.

And in Tacoma, where the air is so dirty it violates the Clean Air Act, authorities are gearing up for what promises to be an arduous and expensive campaign over the better part of a decade to clean up wood smoke pollution. It's an effort that already has some residents chafing at government interference, and one that will set the stage for how other Northwest communities are treated when they bump up against tightened federal pollution standards.

In Tacoma and many towns across the Northwest, wood smoke is a prime culprit in driving spikes of sooty, toxic air pollution that leave some residents – particularly asthmatics, kids and the elderly – gasping for breath. It's especially bad during sunny, cold stretches like those we've seen in recent weeks, because atmospheric conditions trap the pollution close to the ground.

Along with fireplaces and other wood-burning heaters, old wood stoves produce about half the microscopic particles of soot that typically hang in the air when winter air stagnates. (By comparison, industry, already heavily regulated, emits just one-tenth of the Tacoma-area soot pollution.)

In Washington, the state Ecology Department estimates that sooty pollution from sources including wood smoke and diesel exhaust contributes to 1,100 deaths and $190 million in health costs annually.

Ecology says a conservative estimate of the annual number of deaths attributable to soot pollution in Pierce County alone is 140.

The toll in everyday suffering is less easily quantified. But Nancy Gregory, an asthma sufferer who lives southeast of Tacoma near Spanaway, is typical. She says she dreads having to go outside when the winter sky turns blue and air-cleansing rains stop.

"When I walk out to the mailbox, I come back in and sometimes I'm wheezing and I have to go to my inhalers. It makes it hard for me to breathe," said Gregory, 70. For her husband Bryan, 73, it's even worse. He has chronic obstructive pulmonary disease and must breathe from an oxygen tank most of the time. When winter weather turns nice they try to stay inside – but eventually they have to buy groceries and go to doctor's appointments.

"If he gets a coughing attack, he needs a chair," Gregory said. "We can't just let him be walking. He needs something to hold himself up on."

Restricting use of wood stoves that heat so many homes across the Northwest is a difficult proposition, though, because many people can get wood for cheap or for free, and using a wood stove can greatly reduce electricity and natural-gas bills that run wild in the winter. Installing a new clean-burning stove typically costs $2,000 or more – and many argue that it's lousy timing to launch an expensive campaign to clean the air, federal standards or no federal standards.

Alex Smith, 13, admires the fire he built in his family's wood stove in Puyallup.

Yet that's the recommendation of a task force representing local governments, industry, the military and others involved with soot pollution levels in and around Tacoma. Last week the group voted to recommend removal of all wood stoves that don't meet current government standards by 2015 in the area violating the Clean Air Act.

"It scares me," said Gretchen Smith of Puyallup, whose family spends about $380 a month on electricity, including baseboard heaters, even when they use wood heat as a supplemental heat source.

"Most of us are just hoping our cars won't break down and the fridge won't go out or we don't have a medical crisis. ... We don't have much wiggle room in our budget."

The Smiths' wood stove, manufactured before federal rules required large increases in efficiency and decreases in pollution, is one of an estimated 24,000 old, heavily polluting wood stoves spread across the area violating the federal law, which includes most of Pierce County, from near Orting to Steilacoom to Commencement Bay.

Other Pacific Northwest communities, including Klamath Falls and Oakridge in Oregon, the Cache Valley of Idaho, and Libby, Montana, are also in violation of the federal Clean Air Act's rules on soot.

And Washington officials say Yakima, Darrington, Marysville, Vancouver, Wenatchee and Clarkston are at risk of violating the federal soot standards.

"We have a number of communities getting up around those (violation) levels and they're all dominated by wood stoves," said Stu Clark, manager of Ecology's air-pollution program.

Kent, Everett, Olympia, Port Angeles, Spokane, Lynnwood, Mountlake Terrace, Lake Forest Park and south Seattle also have struggled with high soot pollution levels, much of it thought to be traceable to burning wood.

The problem that Tacoma faces today from wood smoke is likely to be a growing problem across the West in years to come, said Jeff Hunt, an air pollution specialist for the EPA's Seattle-based Region 10. Meanwhile, federal soot standards could be tightened as early as 2012, although it would still be a number of years before they were enforced.

In the meantime, though, health damages mount.