Red Deer’s dirty smear

Alot of hay was made back in 2015 about poor air quality in Red Deer, Alta. due to fineparticulate-matter air pollution, referred to as “PM2.5” (for particular matter 2.5 micrograms or less in size).

“Alberta on track to have worst air quality in Canada, provincial environment minister says,” reported the National Post, referring to Red Deer’s air. The CBC reported that the then rookie NDP government in Alberta was quick to announce a plan to address “Red Deer’s air quality, considered the worst in the province due to industrial activity and vehicle emissions.”

With the political froth on this issue settled down, my colleague Aynul Bari and I recently decided to look closer at the supposed problem. We studied data from an air-monitoring station in Red Deer using state-ofthe-art scientific methods and had the results peer reviewed and published in the February edition of the international journal Environmental Pollution. We looked at methods for identifying sources within and outside of Red Deer. These included using the U.S. Environment Protection Agency Positive Matrix Factorization model, Conditional Bivariate Probability Function analysis and a U.S. National Oceanic and Atmospheric Administration meteorological model for air parcel backward trajectory analysis.

We also did a deep-dive analysis — looking specifically at days when PM2.5 levels were higher than typical in Red Deer. Really high levels are when PM2.5 is, well, really high, from forest-fire smoke. We excluded these days from our analysis so as not to skew results towards forest fires. Most of the days that were “higher than typical” weren’t really that high at all — they had much lower PM2.5 levels. They were, in fact, close to or above government standards. People thought these levels were high simply because they placed great significance in government standards. Everything looks normal out there, but apparently not if you exceed government standards.

What we found might be of interest to those not in the know. First of all, we could not figure out how Red Deer has the worst air quality in Alberta. The attached chart shows three-year average PM2.5 levels from 2010 to 2015. If Red Deer is the worst, Calgary and Edmonton are worse than the worst. There are no coal-fired power plants near Calgary to speak of, yet it had the highest PM2.5 levels over the period. Is something amiss? Or perhaps it makes more sense that the larger urban populations in Calgary and Edmonton, their greater population densities (and their associated urban activities) and the effects of geography and meteorology are more important factors for air quality in these settings compared to Red Deer.

As for PM2.5 sources in Red Deer, we found that vehicle, industrial and agricultural emissions made up almost two-thirds of PM2.5. Wintertime PM2.5 levels apparently generate the most political froth. Unsurprisingly, we found that vehicle emissions in and around the city were the most important source of PM2.5 during the winters. Coal-fired power plants located east of the city were only associated with low to average PM2.5 levels during winter; so no smoking