Air Quality Monitoring

Updated on October 28, 2025

Air Quality Monitoring

This project is currently on hold. Check back for updates or contact sustainability [at] rdn.bc.ca (sustainability[at]rdn[dot]bc[dot]ca) for more information.

The Regional District of Nanaimo (RDN) developed a network of PurpleAir sensors to measure fine particulate matter (PM2.5) in the region. Fine particulate is known to influence air quality and have negative human health impacts. These small particles come from many sources, but wood smoke is a primary source in the RDN, as wood burning is often used to heat homes. 

Though we have made progress in reducing PM2.5 from wood smoke through the Community Wood Smoke Reduction Program, there’s still room for continued improvement. To continue making progress, it is important to understand what current levels are, which can be done through monitoring. 

 This project took place in four communities (see map). Sensors in these communities measured:

  • PM2.5 levels
  • Temperature
  • Humidity
  • Air pressure

By gathering data at the local level, we can identify areas of concern. With this information, we can focus on reducing PM2.5 concentrations in the most affected regions. You can find real time air quality readings in various neighbourhoods by zooming into the Regional District of Nanaimo on the PurpleAir’s network map.

Provincial Air Quality Monitors

The BC government maintains PM2.5 sensors at two locations in the RDN. The data can be found at the BC Air Quality page under Current PM2.5 Data.

Frequently Asked Questions

What do PurpleAir sensors measure?

These sensors are primarily used for measuring PM2.5 (particulate matter that is 2.5 micrometers wide and smaller). They also measure the temperature, humidity, and pressure of the sensor. PM2.5 is a concern for human health and is one of the parameters used to develop the Air Quality Heath Index (AQHI) in Canada.

PurpleAir sensors use laser particle counters to count the number of particles by size and the count data to calculate mass concentrations of PM1.0, PM2.5 and PM10. PM10 refers to inhalable particles with diameters that are generally 10 micrometers and smaller; and PM2.5 refers to fine inhalable particles with diameters that are generally 2.5 micrometers and smaller.

A Note on Temperature and Humidity: The temperature and humidity data are for the sensor itself and are not meant to reflect environmental readings. Heat generated by the Wi-Fi module causes an increase in temperature and a decrease in humidity within the housing. PurpleAir found that a correction of -8°F correlates closely to the ambient temperature, while a 4% correction correlates closely to the ambient humidity, and they have adjusted these values on the PurpleAir map to reflect this.

What is the difference between PurpleAir monitors and the air quality monitors used by the BC Ministry of Environment & Climate Change Strategy? 

The RDN Community Air Monitoring Network measures air quality at additional locations throughout the region. These differ from government monitors as they cannot determine legal limits and are not necessarily a good indicator of potential health risks. PurpleAir monitors offer crucial information on current air quality at specific locations and helps us understand overall air quality trends and localized areas beyond provincial monitor coverage.

Air monitors operated by the Ministry of Environment & Climate Change Strategy (MoE) are used to measure air quality to see if pollution levels meet federal air quality standards. There are currently two government monitors in the RDN used for regulation.

How can I acquire a PurpleAir sensor for my community? 

You can purchase a sensor directly from PurpleAir and register the sensor to have it appear on the live map. During the initial installation of the PurpleAir sensor at your residence/business, you must make the data public, specify the location of the sensor by choosing a location for the Map Marker, and provide a publicly visible name for the sensor. The location and sensor name will be visible to the public but will not include an address. When naming your sensor, it is advised to use a general name like a street or Intersection name.

To inquire if there are sensors left to borrow from the RDN Community Air Quality Monitoring Network, please contact sustainability [at] rdn.bc.ca (sustainability[at]rdn[dot]bc[dot]ca).

How much power does the PurpleAir sensor use? 

The power usage is small. The power supply is a 5V at a max of 1.5 A, or 7.5 W. This means the power consumption of a sensor is approximately 1 watt. The daily consumption would be 0.0216 kWh. A PurpleAir sensor’s power supply will work with an AC input of 100-240V.

How much data does the PurpleAir use? 

PurpleAir devices send roughly 8 Kilobytes of data to our servers every two minutes. Thus, if a device were connected to Wi-Fi for 30 days without interruption, it would send approximately 173 Megabytes of data.

Where can I view PurpleAir sensor information? 

PurpleAir sensors that have been made public can be viewed on the PurpleAir Live Map.

 

Contact

For questions regarding this project, please contact sustainability [at] rdn.bc.ca.Â