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Wood Smoke — Health Effects

Burning wood adds harmful fine particles and toxics to the air. “The fine particles (or particulate matter (PM)) in wood smoke can trigger asthma attacks in a manner similar to diesel exhaust or secondhand cigarette smoke,” said  Laura Oatman, environmental research scientist from the Minnesota Department of Health (MDH).

According to the Environmental Protection Agency (EPA): “Wood smoke contains harmful chemical substances such as carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs), dioxin, and inhalable particulate matter (PM). Some of the VOCs are irritating, toxic, and/or cancer causing. One of the biggest human health threats from smoke, indoors or outdoors, comes from PM. Wood smoke PM is composed of wood tars, gases, soot, and ashes. Toxic air pollutants are a potentially important component of wood smoke. A group of air toxics known as polycyclic organic matter includes potential carcinogens such as benzo(a)pyrene.”

At just 2.5 microns in diameter and smaller, 35 to 100 or more fine particles (PM) could fit across the diameter of a human hair. 

Some of the smallest fine particles can go deep into the lungs and can even pass through the lungs into the bloodstream. They can trigger respiratory problems such as asthma attacks and even heart problems. Fine particles are considered especially dangerous for young children with developing lungs, and people of all ages who have asthma, bronchitis, other respiratory problems, and or cardiovascular disease.

How Big is Particle Pollution?

Image source: U.S. EPA, Office of Research and Development

Breathing air containing wood smoke can:

• Irritate eyes, lungs, throat and sinuses
• Reduce lung function, especially in young children
• Increase severity of existing lung diseases such as asthma, emphysema, pneumonia and bronchitis
• Increase risks of heart attacks
• Trigger headaches and allergies

Long term exposure to wood smoke may lead to:

• Chronic obstructive lung disease
• Chronic bronchitis
• Increased risks of cancer
• Cardiovascular disease

Smoke from backyard recreational fires can trigger the same health problems and may penetrate indoors to neighboring homes through intake vents or windows. 

High levels of pollutants leaking from stoves and fireplaces have been measured in some homes with wood burning appliances. Indoors, think twice before using your older non-certified fireplace or wood stove.  The Environmental Protection Agency (EPA) says the average wood-burning fireplace creates 3,370 times more fine particles than a natural gas furnace.  Read more on the EPA’s wood stove Web site and relative emissions of fine particles Web page.

The MPCA strongly encourages those who burn wood to be a good neighbor by building only small hot fires with dry, seasoned wood. It’s also important to properly maintain your stove and chimney.

Always be considerate of family members and neighbors who may have asthma, lung or heart problems. 

For information on best burning methods and a list of what NOT to burn go to Wood Burning Best Practices.

Additional Resources

Health Effects of Wood Smoke

• Health effects of Particulate Matter, Minnesota Department of Health
• Carbon monoxide health effects, Minnesota Department of Health
• American Lung Association
• What is Particulate Matter? American Lung Association
• Health Effects of Wood Smoke from Outdoor Wood Boilers, Washington State Department of Ecology
• Health Effects of Wood Smoke Fact Sheet, Washington State Department of Ecology
• Smoke Gets in Your Lungs, State of New York Office of the Attorney General, August 2005
• Emissions from Outdoor Wood-Burning Residential Hot Water Furnaces, U.S. EPA
• Guidance for Health Professionals, Wisconsin Division of Public Health
• US EPA, National Ambient Air Quality Standards (NAAQS)
• Open Burning, Wisconsin Department of Natural Resources
• Trash and Wood Burning, Wisconsin Department of Health
• Facts About Outdoor Fires, Puget Sound Clean Air Agency
• Health Effects from Burn Barrels and Backyard Garbage Burning