EarthTalk – Are wood stoves harmful to health?

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Dear EarthTalk:
Are wood burning stoves and fireplaces bad for our health?
Name withheld

During the cold gaps of the winter day, a warm, cozy fire may seem like the perfect solution. But burning wood releases far more than just heat—including materials linked to cancer, heart disease and bronchitis.

According to Northwestern University, residential wood burning accounts for more than a fifth of our wintertime exposure to fine particulate matter—Northwest adds dementia to possible outcomes. How is burning wood so detrimental to our health? The answer lies in the process of combustion.

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When wood is not completely burned, it releases creosote, a gummy, foul-smelling residue that sticks to chimneys, flue liners and stovepipes. Creosote is not only a dangerous fire hazard, it is also a concentrate of carcinogens, including substances like benzene and polycyclic aromatic hydrocarbons (PAHs), which can accumulate in the surroundings.

But the arguably more dangerous aspect of wood-burning is the part that’s not always visible: the release of fine particulate matter. “Small particles less than 10 micrometers in diameter pose the greatest health problems because they can get deep into the lungs,” says allergist and immunologist Dr. Cain. “Some may even get into the bloodstream.”

These tiny pieces of inhalable matter, often termed PM 2.5, are especially harmful to older adults and children, especially considering their lower immunity. In fact, Northwestern University reports that about 8,600 premature deaths occur each year due to pollution from residential wood burning.

However, if using a fireplace is the last resort to provide heat, there are a few points to consider. Cleveland Clinic suggests burning dry wood, preferably that stored for at least six months. Also, the room with the fireplace should be well-ventilated and aerated. And materials like plastic, garbage or pressure-treated wood should not fuel the fire; newspaper and small pieces of wood should be used instead.

Nonetheless, the risks cannot be entirely eliminated. While following these procedures may reduce exposure, it doesn’t cut off the creosote, carcinogens and contaminants. Nick Hopkinson, medical director at the British Lung Association warns against any and all use of wood-burning fires: “To protect yourself and others around you...avoid buying a wood-burning stove or using an open fire if you have another source of fuel to cook and heat your home with.”