Smoky Air Quality

Much of Alberta has become inundated with smoke from forest fires burning in British Columbia, carried east by upper level winds.  To be fair, we deal with at least a few smoky days every summer.  It is still uncomfortable, however, and many people can be adversely affected.  People with respiratory difficulties are, of course, most at risk.  The Alberta government has thus issued an advisory, recommending that people avoid strenuous physical activity outdoors.

Air Quality Measurements and the AQI

Air quality is monitored for various regions in Alberta.  The air quality index (AQI) is provided by Alberta Environment (AENV)  as a “qualitative measure of outdoor air”.  The overall AQI for a given region is determined by the worst of several pollutants: carbon monoxide (CO), oxides of nitrogen (NOx) measured as nitrogen dioxide (NO2), ozone (O3), sulphur dioxide (SO2), and fine particulate matter (PM2.5).

Of course, any index requires a scale.  The AQI scale is as follows:

Value Rating
0-25 Good
26-50 Fair
51-100 Poor
>100 Very Poor

Each pollutant above is measured and assigned a value.  The highest value becomes the rating for that region.  Also, it is important to note that each province has its own independent system.  It is therefore impossible to reliably correlate across the country.

Alberta’s Airsheds

For the purpose of air quality monitoring, the province of Alberta is divided into nine regions, called airsheds.  Eight airsheds are up and running, and the other is currently under development (according to the Clean Air Strategic Alliance (CASA) website, but who knows how often that site is updated).  The nine regions are:

Alberta has basically followed the lead of Saskatchewan in developing airsheds.  The regions covered by Alberta’s airsheds should be familiar to those who remember the old health regions – they’re very similar.


The Calgary Regional Airshed Zone Society is a “non-profit association with members from government agencies …, non-government organizations, industry and the public.”

CRAZ Monitoring Stations

Three active monitoring stations located in Calgary, used to determine air quality for the entire CRAZ.

The most disturbing thing to my mind is that the AQI rating for the entire CRAZ is based on three active monitoring stations located in Calgary (see the map to the right).  However, there are other active monitoring stations in southern Alberta: one in Lethbridge, and another (for the Palliser Airshed Society) in Medicine Hat (which apparently is not currently working).

Of course, there is also the problem that the equipment is old (1970s vintage), likely resulting in increased maintenance costs.


Each airshed zone must submit its data to the Alberta Ambient Air Data Management System – CASA’s data warehouse.  It is designed to be  a central data repository for Alberta’s 140 active monitoring stations.  Should you wish to view the data for yourself, feel free to navigate to the website at


2 responses to this post.

  1. Posted by browtm on August 22, 2010 at 16:06

    Going to CRAZ’s website (that’s the most unintentionally meaningful acronym, btw, since GAAP- Generally Accepted Accounting Principles), it’s interesting that not only do they not put current conditions on their homepage, they make you register to get at the information at all… weird.

    And, as usual, it’s good to see world-class Alberta, not in the lead, but following someone else.

    You should have seen the smoke around Whitecourt a few days ago- I’ve never seen it that thick. It was like fog…

    • I’m not surprised, actually (about the website). When I tried to register a few months ago, I was met with nothing but SQL database errors. This was topped by the email bouncing back from the non-existent address they have posted. Based on that track history, I was rather surprised to find their phone number is valid. I have yet to actually speak to anyone in their office (assuming they actually exist) about their shitty website. The CASA site is not fantastic, but at least you can use the features offered.

      My level of expectation for this province’s performance is pretty low (again, given the track record). The day we take the lead will be rather astonishing!

      Driving to work at 4:00 AM on Friday, I noticed the smoke was much thicker than on Thursday. It also looked like a fog, but certainly smelled like smoke.

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