Do Household Wood Stoves Pose a Health Risk?
While any form of energy used for heating will impact the environment in some way, burning wood does has its merits. For one thing, wood is a renewable commodity. For another, heating with wood generally calls for a centrally located stove. Because the heat radiates outward, heating furniture and floors as it moves, the heat tends to stay locked in the home longer, making it more comfortable and efficient heat.
And yet the wood stove, while perhaps the most perfect way to heat a home, can be very dangerous both to the individual user and to the planet when a homeowner does not follow correct procedures. According to a six-year study conducted by Dr. Alejandra Ramirez-Venegas, M.D. and six associates from the COPD Clinic at the National Institutes of Respiratory Diseases in Mexico City, cooking over wood stoves for long periods of time can create COPD problems.
"Biomass (wood) smoke is composed of a relatively equal mixture of coarse and ultrafine particles and can penetrate deeply into the lung, producing a variety of morphologic and biochemical changes," said Dr. Ramirez-Venegas. This information was determined based on about 200 hours of wood cooking exposure per year. Incorrectly designed wood stoves tend to allow smoke to enter the home, which can cause asthma flare-ups. Incorrectly cleaned stove pipes can cause home fires, and cooking over wood stoves can cause chronic lung diseases, such as COPD (Chronic Obstructive Pulmonary Disease). However, there are various ways to keep a wood burning stove from emitting large amounts of smoke, and many individuals who heat with wood claim there is no better source:
Proper design is the first step when using a wood stove to heat a home. If the stove is not designed correctly, both indoor and outdoor pollutants will be obvious. Any time smoke is entering the home you have a problem. Additionally, if the stove pipe outside the house is not positioned correctly, the wind can cause a back draft that can force smoke into the building.
Unfortunately, burning wood efficiently often means something entirely different to each individual. Burning wood efficiently does not mean burning all types of wood, nor does it necessarily mean burning wood down to ashes. What the phrase "burning efficiently" means is using the correct types of wood, such as seasoned wood (wood that has sufficiently dried) that will not produce excessive amounts of smoke. It also means burning only wood. Plastics, leaves and many other types of trash or compost produce excessive amounts of toxic smoke and should never be burned. Plastic should never be burned in a wood burning stove or outdoors in a trash receptacle or campfire. Plastic gives off toxic fumes that come from a deadly toxin called dioxin. One of the deadly chemicals that becomes airborne when plastics are burned is TCDD (tetrachloro-dibenzo-dioxin). At very low level of TCDD also forms when wood is burned.
Avoid a smoky smoldering fire. Burning a bright hot fire is the best way to avoid smoke. Wet or young wood that is fresh will smoke. Use only seasoned wood. Seasoned wood will be much lighter and the smell will be less pungent. If using very dry wood, such as kindling, mix it with a few pieces of seasoned wood that will not burn as quickly and produce as much smoke. Regardless of which type of wood is burned, when burned hot, less creosote will develop. Creosote is a thick tar-like substance that coats the chimney (and lungs) and has the potential to catch fire. It is estimated that approximately 75 percent of all heating fires and 25 percent of all residential fires in the United States are caused by creosote buildup in the chimney where wood burning stoves are used as the primary source of heat. The chimney should be swept out often with a long-handled chimney brush to remove creosote buildup.