Many people use woodstoves or fireplaces to heat their homes. Some because they enjoy the atmosphere a fire creates and some to save on heating costs.
Brian Garvey has been using a woodstove to heat his pre-Civil War home in Monroe County for 40 years. His fuel comes from his own 185 acres of forested land.
“Most of this wood is ash,” he said. “We’ve had a lot of ash trees die because of the emerald ash borer. Most of this wood was down or I took down standing dead trees.”
Garvey seasons the wood himself, drying it for at least a year – not only because dry wood burns more efficiently, but also because wet wood leaves creosote, which can block airflow and start chimney fires.
He says looking at and feeding a fire all winter long provides him with a certain sense of connectedness.
“It connects me in that same way that growing your own food connects you to a meal,” he said.
Brian Garvey has been using a woodstove to heat his home in Monroe County for 40 years. (Devan Ridgway, WFIU/WTIU News)
But burning anything sets off combustion, creating particulate pollution that can have negative health impacts, according to Sarah Commodore, an assistant professor at Indiana University’s Department of Environmental and Occupational Health.
Commodore says these tiny particulates, referred to as PM2.5, are finer than the finest hair on your head.
“It goes really straight into your lungs, and it lodges deep in there,” she said. “And sometimes it can easily go through and enter into your bloodstream, enter into places that you don't want it to go, like your brain.”
Your brain, heart, and other vital organs. Commodore says it’s a combination of what’s in the wood and on the wood, a combination of particulates and gasses, that makes up the threat.
“And then sometimes you can have some of the particles lodging together to become another particle, because they just happen to react together and form something new that didn’t even come out of that product,” she said.
She points to volatile organic compounds – VOCs – and hydrocarbons containing benzine, which is carcinogenic. Commodore says repeated exposure creates what’s referred to as insults to the cells of our organs and can set us up for disease.
“It takes years for the cells to start to abnormally divide, but that insult … If you keep getting it, eventually you're stressing your body out to the point where it can’t repair all that damage anymore.”
Dr. MeiLan Han is chief of Pulmonary and Critical Care Medicine at the University of Michigan. She’s also a national spokesperson for the American Lung Association. Among the illnesses Han studies is chronic pulmonary disease, or COPD, a common chronic lung condition.
“People typically think about it as being related to tobacco smoke,” she said. “Actually, about a quarter of people who have COPD never smoked, so we think in those individuals there’s probably a combination of factors, including environmental and noxious exposures.”
Han points to a Canadian study that reveals smoke from biomass fuel as a discriminative factor in non-smoking women’s susceptibility for COPD.
And particularly concerning is exposure to noxious agents when young. It can lead to unhealthy outcomes.
“There is a lot of data that pollution is bad, just straight up, you know pollution and pregnancy is bad, it’s associated with worse infant outcomes,” she said.
Han points to research indicating children exposed to ultrafine particulate matter not only are at increased risk for bronchitis and pneumonia, but can also develop defects.
Han says our lungs continue to develop until age 25. So depending on when and how long the cellular insults occur, they might impede lung development. Or in adults, speed lung decline.
As he enjoys the warmth of his homegrown fire, Garvey says, to his knowledge, his family’s health hasn’t been negatively impacted by woodsmoke. But he took steps to guard against indoor air pollution when setting up his woodstove. To start, he made sure it had a baffle.
“And what that does is help oxidize volatile gases,” he said. “The initial burn gives off a volatile gas and that can be burnt again essentially. Another way is to have clean chimneys -- tile lined and/or stainless piping. Another is to have a good draw on your chimney … You don’t want smoke rolling back when you open the door.”
The U.S. Environmental Protection Agency’s mandatory smoke emission limit for wood stoves is 2.0 grams of smoke per hour, which took effect in May 2020. The EPA also has guidance for choosing an EPA certified wood heater at www.epa.gov.
Yet many health advocacy organizations, including Doctors and Scientists against Wood Smoke Pollution, argue that any wood burning emits damaging particulates and toxins, even if done through a “certified” stove.
