How the Calgary Region Airshed Zone measures pollutants to formulate air quality health index

As wildfires burning in B.C. and Saskatchewan blow smoke into Alberta, the Calgary Region Airshed Zone has been busy monitoring and providing information on the local air quality.

Agency uses sensors and operates 3 air monitoring stations, plus a mobile unit

Calgary Region Airshed Zone executive director Jill Bloor, with air quality manager Mandeep Dhaliwal, holds a PurpleAir sensor that provides real-time measurement of pollutant particles, which can be displayed on a map. (Monty Kruger/CBC)

This feature on how the Calgary Region Airshed Zone monitors air quality was originally posted on July 20, 2021:

As wildfires burning in B.C. and Saskatchewan blow smoke into Alberta, the Calgary Region Airshed Zone has been busy monitoring and providing information on the local air quality.

The not-for-profit group uses air monitoring stations and sensors to provide real-time data to inform the air quality health index (AQHI) for several municipalities, including Calgary, Airdrie and Canmore.

In mid-July, it increased its monitoring in anticipation of summer wildfires.

When smoke engulfs a city, the agency is able to measure different pollutants that are in the air to help formulate the AQHI so that the public and vulnerable populations can be made aware of the risk of being outside.

For example, wildfire smoke on Sunday pushed the AQHI for Calgary to 10+, the highest and most dangerous tier, which means "very high risk."

High-risk populations, such as those with cardiopulmonary diseases, should stay indoors when the level is that high.

WATCH | Calgary's air quality monitors catch spike in hazardous particles from B.C. wildfires.

Non-profit expanding resources to keep tabs on Calgary-area air-quality amid wildfires.

2 months ago
Calgary Region Airshed Zone (CRAZ) recently started expanding their network by installing smaller monitors dedicated to monitoring hazardous particles in the air. 2:23

"The number that comes out of these stations is one-hour averages of each pollutant, and then we compare that number to air criteria that is established by the Alberta government," said Mandeep Dhaliwal, the air quality manager for the agency.

"On a normal day, air quality in Calgary is very good compared to other parts of the world, but events such as forest fires or wildfires — they do not respect any boundaries."

The society operates three air monitoring stations in Calgary on behalf of the Alberta government, plus one that is mobile and is currently in Canmore, pictured. (Submitted by the Calgary Region Airshed Zone)

'It gets right into the capillaries of your lungs'

The Calgary Region Airshed Zone is one of several airsheds in Canada that share air quality information with all levels of government and community stakeholders. 

It operates three air monitoring stations in Calgary on behalf of the Alberta government, plus one that is mobile and currently in Canmore. These are linked to others across the province and country.

The stations are used to measure compounds in the air in addition to PM 2.5 — particulate matter 2.5 microns or less in size. These tiny particles of organic chemicals, soil, metal and dust can create a haze and reduce visibility when levels are elevated. 

Because they are so small, they can get deep into the lungs. Short-term exposure to high levels of PM 2.5 can cause eye, nose, throat and lung irritation, while longer exposure can adversely affect overall health.

Calgary reached an air quality health index of 10+ on Sunday, which was downgraded to 9 on Monday. It dropped to 3 on Tuesday. (Monty Kruger/CBC)

Last year, the agency partnered with Environment and Climate Change Canada to install smaller, lower-cost sensors across the region that measure PM 2.5 on a continuous basis, and supplement the data gathered by the stations.

"I always use the analogy that if you're driving down a dirt road with your windows down, and you get to the end of it and you cough, you're coughing up everything other than PM 2.5," said Jill Bloor, the executive director of the agency.

"It's so small that it gets right into the capillaries of your lungs, and continued exposure can damage your lungs and your breathing ability." 

70% of air pollution comes from vehicles, agency says

In addition to monitoring the air quality in the region, Bloor and Dhaliwal said the agency also helps educate the public about where pollutants come from and what can be done about them.

"The data is used by the government to manage air quality, and also by educational institutes to see where we are currently, and where we're going in the future, and how we can [reduce] air pollution," Dhaliwal said.

So far, the agency has given two Alberta schools air quality sensors so that students can learn about pollution. It plans to give away more.

Meanwhile, it has also helped to develop idle-free campaigns in Wheatland County and Okotoks, Alta.

Though wildfires are currently the main source of PM 2.5 in the air in Calgary, on a regular day, the majority of the particulate matter we breathe in comes from diesel or gasoline combustion, Dhaliwal said.

In fact, Dhaliwal said about 70 per cent of air pollution comes from our vehicles, which has led the agency to embark on initiatives to raise awareness about the impact of idling and the importance of carpooling in the Calgary region.

"Together, we can make a difference," Dhaliwal said. "[And] we can reduce the idling of our vehicles, which impact [air quality] greatly."

With files from Monty Kruger


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