Wood smoke reduction

Wood smoke affects everyone, but especially children, seniors, pregnant women and people with existing lung and heart conditions. The BC Lung Foundation has identified many hazardous substances in wood smoke including: fine particulate matter (PM2.5), carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). Exposure to wood smoke increases the likelihood that health conditions will develop.

Exposure to smoke can worsen conditions like asthma or COPD, reduce lung function and increase the risk of a heart attack or stroke. It can also cause lower birthweights, ear and respiratory infections in children and shortened lifespans.

What is fine particulate matter (PM2.5)?

  • PM2.5 is the scientific name for miniscule particles with a diameter of less than 2.5 micrometers (a micrometer is a millimeter, divided into a thousand!) PM2.5 is a key component of smoke.
  • Measuring about 20x smaller than a human hair, fine particulate matter is small enough to inhale, travel through our bloodstream, and seep through cracks in buildings even when the doors and windows are closed.
  • Research suggests that there is no safe level of PM2.5. Exposure to PM2.5 can negatively impact the heart and lungs and can lead to health issues such as asthma symptoms, chronic bronchitis, and heart attacks. Exposure to PM2.5 is also linked to more frequent emergency room visits and hospitalization for respiratory and cardiovascular problems, as well as an increased risk of premature death.

Reducing smoke impacts

The City of Courtenay, Province of BC and individual homeowners are taking action to reduce smoke impacts. Here’s some of the measures that reduce the impacts of wood smoke in the community:

Wood smoke impacts

The provincial air monitoring station at Courtenay Elementary School has been collecting data since 2011, and tracking how conditions have changed at this location over time.

To understand how air quality varies across the region, additional PurpleAir monitors have been installed by the City as well as local organizations and residents. These monitors report real-time measurements of fine particulate matter, and report them on the online map.

Measurements are compared against BC Air Quality Objectives, which specify the maximum allowable concentration of pollutants.

What we have learned from air monitoring:

  • The average annual concentration of fine particulate matter, a key ingredient in smoke, has been dropping since 2017, which indicates the air is less smoky on average.
  • While the improvement can’t be attributed to a single factor, likely reasons for this trend are increased regulation of slash burning and reduced use of wood burning appliances.
  • Daily spikes of fine particulate matter occur during winter evenings and early mornings from October to March. During these times, air quality does not meet the BC Air Quality Objectives. 
  • The pattern seen in the air quality readings is consistent with the time of day that people are likely to be home and using wood burning appliances.
  • On winter nights, there can be wide variation between the monitor readings. Older neighbourhoods, with more homes equipped with wood burning appliances, consistently have the highest readings of fine particulate matter. 
  • The location of wood burning appliances in our neighbourhoods, makes them more impactful on individual health than other sources of smoke that originate far away (such as wildfires in the summer months).
  • Our location tucked between the mountains and ocean is beautiful – but at night, these features create atmospheric conditions that trap pollutants close to the ground.

For more information about monitors and readings, visit our Air quality monitoring page.

Average Hourly Measurements: Looking at the average hourly concentrations of PM2.5 during a typical winter day, we can see that after 5 p.m., fine particulate matter exceeds BC air quality objectives, peaking at 9 p.m., and remains elevated until early morning.

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A graph showing hourly PM₂.₅ concentrations. Levels peak around 9 p.m. and drop significantly by noon.

Average Monthly Measurements:.The graph below shows the average monthly concentrations of PM2.5. During the winter, from mid-September to mid-March, concentrations of PM2.5 exceed the BC Air Quality Objectives. This timing aligns with the seasonal use of residential wood burning appliances.

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A graph showing average PM₂.₅ levels over 12 months. PM₂.₅ peaks in December, exceeding BC’s air quality objective, and drops to a low in June.

More information:

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