Amid snowy tree branches and slush-dappled parked cars, the aroma of wood smoke makes its way down many Rochester streets. Even if you don't burn wood yourself, you get a taste of the season and all its associations --- like that "chestnuts roasting on an open fire" thing.
The romance invites itself into your home, too, on your clothes and hair or through cracks in window frames and doorways. However the smoke gains entry, it's fun to guess if your neighbors are burning apple wood or hickory. Makes you want to pull on the slippers, pet the dog, and mull the cider.
But if you have a breathing problem, you might sniff at the atavism. Let's face it, residential chimney smoke --- whether it comes from apple wood or old newspapers and plastic bags casually tossed into the fuel mix --- is still smoke. And it's a major urban pollution source and health hazard, just as surely as if it came out of a truck tailpipe.
Listen to the federal Environmental Protection Agency.
"Wood-burning appliances and fireplaces," says an EPA fact sheet, "may emit large quantities of air pollutants. Wood smoke contains hundreds of chemical compounds, including nitrogen oxides, carbon monoxide, organic gases, and particulate matter... [M]any of these compounds can cause serious health problems, especially for children, pregnant women, and people with respiratory ailments. Several of these pollutants have demonstrated cancer-causing properties similar to cigarette smoke..."
The private sector makes a similar judgment. An advisory from the Sierra Club's Minnesota affiliate, for example, says wood smoke contains things like sulfur dioxide (a key regulated air pollutant), formaldehyde, dioxins (a champ among carcinogens), and a class of toxics called "volatile organic compounds." And Minnesotans need to know, since northern states with low winter temperatures and large areas of woodland have come to depend on wood burning for a significant fraction of their energy supply.
Gases like carbon monoxide are nothing to ignore. But particulate matter --- "PM," as regulators and watchdogs call it, or soot and ash, as it's known to laypeople --- is climbing higher and higher on the list of concerns. (Compare the story of diesel exhaust and school buses, City Newspaper, September 18.) And it's particulate matter that gives wood smoke its range of "flavors."
The American Lung Association's Washington State affiliate --- again, a state with plenty of wood burners --- tells why these flavors are no treat. Extremely small particulates from wood burning, says an ALAW backgrounder, "can slip past the respiratory system's natural defenses" and "reach the alveoli, tiny air sacs where oxygen enters the blood stream." Once there, says the backgrounder, the particulates "interfere with oxygen uptake," with obvious implications for people with breathing problems. Moreover, says the backgrounder, "toxic and cancer-causing compounds can 'hitchhike' into the lung on [the] particulates and be directly absorbed..."
All in all, particulates in wood smoke and other substances can harm anyone. But asthma sufferers, many seniors, and the very young --- those who have impaired or undeveloped lung capacity --- are the ones who suffer most.
So wood smoke is nothing to sneeze at. But how much of it is out there, anyway? Enough to be a serious pollution problem for entire communities?
Overall, the "hearth industry" is booming. The Hearth, Patio, and Barbecue Association, a trade group, says that in 2001, around 1.6 million "hearth appliances" --- stoves, fireplace inserts, etc. --- were shipped in the US. This was a 3 percent decline from the year 2000, but annual sales of these devices, says the association, have soared 112 percent since 1992.
According to the association, around 40 percent of units shipped in 2001 burned cordwood; almost all the rest burned natural gas. (Some stoves burn wood pellets, coal, or oil, or run on electricity. And then there's another category: wood furnaces, which we won't get into here.)
But, says the association, year 2000 shipments of wood-fired units increased by five percent over the year before, while shipments of gas units declined 11 percent. The association attributes this to several things: higher natural gas prices; more interest in alternative fuels after the California energy crunch; and the economic recession, including a jolt from September 11. Yet over the last five years, says the association, there has been a discernible movement toward gas and away from wood.
In any case, the figures show that a lot of new wood-burning devices are going into American homes. For example: Using federal statistics, the association estimates that nearly 55 million US homes had fireplaces in 2000, though only around 59 percent of the fireplaces were actually usable. (Note that fireplace usage may not correspond with figures for the use of wood as a secondary heating fuel --- not surprisingly, since many open fireplaces are just for show.)
The federal Department of Energy says that in 1997, 13 percent of US households used wood as a "secondary heating fuel." That was down eight percent from 1987, thanks to an increase in the use of electric heaters. But residential wood use in 1997 was about the same as in 1978, during alternative energy's glory days after the 1973 oil embargo.
New York has its share of serious wood burners. The 2000 US Census found that wood was the primary heating fuel in 83,000 of the state's 7 million households.
Numbers aside, the question comes up: Is anyone regulating fireplaces and wood stoves and their air emissions?
Yes and no.
First, local governments certainly do regulate some aspects; the biggest concern is preventing homes from burning down. Juan Linares, who monitors building code compliance for the City of Rochester, says city inspectors make sure contractors and homeowners have followed product requirements before granting permits. "The manufacturers," says Linares, "give us information about how far [stoves and stovepipes] have to be from combustible walls." The devices, he says, must have "UL certification or the equivalent." The same goes for natural gas-burning stoves, whether vented or ventless. (Linares adds that people who suspect an installation was done without proper inspection can contact their NET office for help.)
"The city has no air emissions regulation authority of any sort," says Edward Doherty, the city of Rochester's Commissioner of Environmental Services. Nor does the city offer financial incentives to help people switch from older, dirtier stoves to cleaner-burning new models, according to Doherty.
On most things wood smoke-related, it's the state and feds that have the power. The federal Environmental Protection Agency, for example, has regulated emissions from so-called "airtight stoves" since the early 1990s. The EPA regulates only the manufacturer, though, not the homeowner or other "end user." And all stoves built before the regs took effect are "grandfathered," that is, exempt from the regulations. The quasi-regulation has achieved some benefits, however. "Older stoves and fireplaces released from 40 to 80 grams per hour of smoke; the new EPA-approved stoves produce from two to five grams per hour," says HearthNet, an online trade publication.
State and federal governments have run incentive programs off and on, too. Last year, for example, a consortium of retailers and manufacturers in 11 states, including New York, and the province of Ontario conducted the "Great Wood Stove and Fireplace Changeout." The program gave cash incentives, varying with jurisdiction, to people who bought new units --- equipped with catalytic converters, afterburners, and the like --- to replace older, dirtier ones. Agencies in the Great Lakes region were especially concerned about benzo(a)pyrene, a constituent of wood smoke that can filter down and harm aquatic ecosystems.
Though the heating season is upon us, we've already missed "Wood Smoke Awareness Month," as declared by a California-based not-for-profit group, Clean Air Revival.
The group and its "Burning Issues" campaign, led by activist Mary Rozenberg, are dedicated to weaning people from wood burning, pure and simple. The campaign, says Rozenberg via e-mail, "is opposed to all wood burning because none of the new wood burning technology comes close to reducing particulate pollution and carcinogenic byproducts to the levels that are available from burning cleaner fuels like [natural] gas and oil."
Other environmental groups don't go that far. For example, the Sierra Club of Minnesota urges people to switch from older stoves to new EPA-certified models, for example. But the American Lung Association of Washington --- another state that regulates wood burning pretty strictly --- seems to back Rozenberg up.
First, the ALAW suggests some minor reforms, so to speak: using certified equipment and using optimally dry wood for fuel. (Too many suppliers deliver wet, unseasoned cordage.) And the group says it's wise to "stay alert to air-quality conditions" and keep your fireplace off-line during pollution alerts.
But the ALAW's bottom line is this: "Replace your old wood stove with a natural gas, propane, or electric furnace." That might make some people do a slow burn, but it probably makes sense for densely populated areas.