The City of Courtenay has installed PurpleAir monitors on public buildings across the city, adding to the growing network of private and public air monitoring locations across the Comox Valley. These monitors measure fine particulate matter (also known as PM_2.5), which threatens air quality in the Comox Valley.

By increasing the number of air monitoring locations, we can learn more about how PM_2.5 concentrations vary in our neighbourhoods over time. PurpleAir monitors are low cost air quality sensors that use laser particle detectors to measure PM_2.5 concentrations in the air. Real-time readings from these sensors are available online at: https://map.purpleair.com/

The BC Ministry of Environment and Climate Change Strategy endorses the use of PurpleAir monitors and has created data management tools to include measurements from these devices in the provincial air monitoring dataset.

Understanding the Readings

Readings from PurpleAir monitors indicate the amount of PM_2.5 in the air at a specific location, at a moment in time. The higher the number, the more PM_2.5 in the air. The monitors are responsive to local sources of PM_2.5, so the measurements may change quickly.

• PurpleAir monitors are sensitive to humidity, so a correction factor must be applied to allow for an accurate comparison to the BC Air Quality Objectives.  

• Corrected measurements are reported on a map hosted by the University of Northern British Columbia (UNBC) Atmospheric Sciences program: UNBC Hourly PM_2.5 Observations map

•  The BC Air Quality objectives for fine particulate matter are:
  • 25 ug/m³ (micrograms per cubic meter), averaged over a 24-hour period; and
  • 8 ug/m³ (micrograms per cubic meter), averaged over a year.

How can I monitor air quality in my neighborhood?

Consider expanding our local network by installing your own PurpleAir Monitor! The sensors can be purchased directly from PurpleAir, and they require a USB power source and access to wireless internet.