This week several media outlets have highlighted air quality modelling work conducted by Environment Canada under the Joint Oil Sands Monitoring Plan. Specifically, Environment Canada presented two video animations at the Environmental Monitoring and Science (formerly AEMERA) February Oil Sands Monitoring Symposium:
- An animation showing the change in nitrogen dioxide (NO2) levels over the oil sands region. This is based on remote sensing satellite measurements taken from the Ozone Monitoring Instrument as part of NASA’s Earth Observing System. The results show a general decline in NO2 levels from Alberta power generation facilities and major urban areas. There is a general increase in NO2 levels in the oil sands region. These results are consistent with air emissions and ambient air quality data: Video (NO2)
- An animation of sulphur dioxide and the Air Quality Health Index demonstrating how results can be visualized from the Environment Canada high resolution model (GEM-MACH). This modelling is for the August-September 2013 time period. Note that these were presented only for demonstration purposes intended to demonstrate the visualization product from the GEM-MACH model: Video (SO2)
It is important to note that particulate matter (PM2.5) measured at ambient monitoring stations can be either primary or secondary. Primary particulate matter is emitted directly out of an industry stack or automobile exhaust while secondary particulate matter is a result of emissions of gases (such as nitrogen sulphide and sulphur dioxide) that are transported and transformed in the atmosphere to form particulate matter far downwind. As an example, sulphur dioxide and nitrogen dioxide emitted by tall stacks associated with power generation facilities or oil sands facilities can be transported hundreds of kilometres downwind and can be converted to secondary particulate matter during transit.
Air pollution standards for particulate matter and other pollutants have become increasingly stringent over the last 20 years. As an example, the 24-hour PM2.5 standard under the former Canada-wide Standards was 30 ug/m3. The new national standards (Canadian Ambient Air Quality Standards) for 24-hour concentrations of PM2.5 is 28 ug/m3 and will likely be more stringent by 2020. Also, the calculation process for the national standards uses the station with the worst air quality to represent the region while the former process used an average of all monitoring stations in the region. This increased stringency of the national standards is intended to force improvement of air quality for specific pollutants that are known to be potentially harmful to human health.