Many people heat their homes with a wood burning stove or fireplace in the colder months. What they may not know is that burning wood releases harmful pollutants into the air they breathe. If improper burning techniques and inefficient wood-burning appliances are used, wood burning can lead to serious health effects.

• Volatile organic compounds can cause respiratory irritation and illness. Some VOCs that come from wood-burning appliances are capable of causing cancer. 
  
• Polycyclic aromatic hydro-carbons are believed to pose a risk for cancer with prolonged exposure.
  
• Particulate matter is a mixture of microscopic particles. Breathing in these particles can cause respiratory problems, and even result in death for people who have a history of heart or lung disease.
• Dioxins and furans can cause problems for the skin, liver, immune system, nervous system and reproductive system, and may cause certain types of cancers.
  
• Acrolein can cause eye and respiratory tract irritation.
• Carbon monoxide is a colourless, odourless and poisonous gas that reduces the amount of oxygen in the blood. Low levels over long periods of time are dangerous, and high levels can cause unconsciousness and even death.
  
• Nitrogen oxides can impair lung function, irritate the respiratory system and, at very high levels, make breathing difficult, especially for people who already suffer from lung diseases.
  
• Formaldehyde is a colourless gas with a sharp odour. Moderate levels can cause burning of the eyes or nose, as well as a sore throat.
  
• Hydrocarbons can damage the lungs.
  

Remember: With all toxic substances, the risk of health effects depends on many factors, including the way a person is exposed, how much a person is exposed to, individual susceptibility, and more.

What can you do?

• Only burn dry, seasoned hardwood. Burning wood that’s “green” or wet causes a lot more smoke.
  
• If possible, store wood outside, making sure that it’s off the ground and properly covered. Storing green wood inside can increase humidity and lead to mould growth.
  
• Use small pieces of wood kindling and newspaper to start your fire, adding larger pieces of wood as needed.
  
• Don’t leave fires to smoulder. Small, hot fires produce much less smoke.
  
• Open the stove or fireplace damper to increase air circulation and improve burning. Smoke is a sign of oxygen starvation and incomplete burning.
  
• Don’t completely close your damper overnight. This creates excessive emissions and can lead to the formation of creosote (an oily residue that forms from unburned wood gases).
  
• Don’t burn garbage, plastic, cardboard or Styrofoam. Burning garbage releases poisons.
  
• Never burn pressure-treated or painted wood, particleboard or plywood. These woods contain toxic chemicals.
  
• Have your wood-burning appliance inspected and cleaned at least once a year.
  
• Keep your stovepipe and chimney clean, and remember to empty ashes often.
  
• Install at least one carbon monoxide detector in your home.
  

Sources:
British Columbia Lung Association
Health Canada

Grey Bruce Public Health: Wood Burning and Possible Health Effects

Health Canada: Wood Smoke

My Senior Site: Wood Burning and Your Lungs

Toronto Public Health: Wood Burning in Your Home

Wood Burning Appliances