Air Quality

Data from the provincial air monitoring station indicates fine particulate matter is the greatest risk to air quality in the Comox Valley. Common sources of PM2.5 include: smoke from residential wood burning appliances, open burning, and wildfires. Our atmosphere is susceptible to atmospheric inversions which trap smoke near the ground, further impacting air quality.

Smoke contains fine particulate matter (PM2.5) and other harmful pollutants.

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.

Here's how the City of Courtenay is addressing air quality concerns:

Air quality monitors
We have contributed to the local air monitoring network by installing PM2.5 air monitoring devices to help our community become more informed, and identify which areas may need more support to improve air quality.

Updated bylaws
We've updated the Prevention of Public Nuisance Bylaw to regulate smoke that is causing a nuisance, with a goal of voluntary compliance over enforcement.

You can help improve our air. Heat your home with a cleaner heat source and save wood burning appliances for power outages or extreme weather.

Explore the following resources to learn more about wood smoke impacts and solutions.

Does Courtenay have an air quality issue?

Courtenay often experiences periods of poor air quality during winter evenings and periods of wildfire smoke. Outside of these times, Courtenay has good air quality.

Air quality is measured year-round at the provincial air monitoring station located at Courtenay Elementary. Measurements are compared against the BC Air Quality Objectives, which specify the maximum allowable concentration of pollutants.

Measurements of fine particulate matter, also known as PM2.5, exceed the BC Air Quality Objectives on multiple days per year. Hourly measurements of PM2.5 are highest during winter evenings and periods of wildfire smoke.


Image source: U.S. Environmental Protection Agency


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.



Where is PM2.5 coming from?

In the City of Courtenay, the primary source of PM2.5 is residential wood burning appliances.

The graph below shows the average monthly concentrations of PM2.5 measured by the provincial air monitoring station in Courtenay. During the winter, from October to April, concentrations of PM2.5 exceed the BC Air Quality Objectives. This timing aligns with the seasonal use of residential wood burning appliances.

The next graph shows the average hourly concentrations of PM2.5 during a typical winter day. After 6 PM, fine particulate matter exceeds the BC Air quality objectives, peaks at 11 PM, and remains elevated until morning. The timing corresponds with the daily use of residential wood burning appliances. 


Since wood burning appliances are commonly used after dark, when smoke is not visible, the impact to air quality may be hard to see. Wood burning appliances that operate frequently have the greatest impact on local air quality. Residents can improve local air quality by burning less often.

Other sources of PM2.5  include provincially regulated open burning, such as land clearing and slash burns; and wildfire smoke.