This is the eighth in a series of reports by Dr. Peter Tsigaris, Professor of Economics, Thompson Rivers University, and Dr. Robert S Schemenauer, Environment Canada Research Scientist, retired, that have been written to inform the public, politicians and government decision makers on the quality of the air in Kamloops.
By Dr. PETER TSIGARIS
and Dr. ROBERT S. SCHEMENAUER
THIS REPORT EXAMINES the air quality measurements made at the Federal Building monitoring station in downtown Kamloops for the years 2016 and 2017. The report compares the data to those collected since data records began in 1998.
As expected, peaks in the annual averages of fine particulate concentrations in Kamloops are associated with years with more extensive wildfires but their magnitude is not obvious. This study provides information on the magnitude of such peaks. Data for the years 2016 and 2017 are also compared to those for four other cities in the Interior of British Columbia.
The years 2016 and 2017 present us with a clear contrast. In 2016 we did not have a large contribution from wildfires to the airborne particulate concentrations in Kamloops. The year 2016 had an average annual PM2.5 concentration that was among the lowest measured since observations began in 1998.
Still, it was essentially at the maximum recommended value set in the provincial Air Quality Objectives. The air was not clean. It simply had lower particulate concentrations than most years. The year 2017, on the other hand, was severely influenced by the large wildfires, most located some tens of kilometres away from the city of Kamloops. The airborne particulate concentrations in 2017, whether looked at on an annual, daily, or hourly basis, were the highest since measurements began in 1998.
The focus of this report is on measurements of concentrations of fine particulates in the air, PM2.5 (in micrograms per cubic meter, μg/m3). The mean annual value of PM 2.5 for 2016 was 7.9 μg/m3 at the downtown site. The mean annual value for 2017 was 15.3 μg/m3.
Previously the worst annual average PM2.5 in Kamloops was 11.1 μg/m3 in 2003, calculated using the data protocol of Tsigaris and Schemenauer (2014b), when the Strawberry Hill wildfire occurred on the north edge of the city.
The uncorrected annual average value for 2003 would not allow for a direct comparison to present measurements. It would make the 2003 air quality look like that in 2016, which had one of the mildest forest fire seasons since measurements began in 1998. The provincial government’s description of annual wildfires called the 2003 forest fire season “Catastrophic” and the year of 2017 “The worst wildfire season(s) in British Columbia’s history.”
The air was cleaner in Aberdeen than downtown for nine months of the year in 2017 but in July, August, and September the PM2.5 values were slightly higher at the top of the valley. The differences are small but consistent. It implies that during this period of about three months, the air in the valley was well mixed from the level of the rivers to the top of Aberdeen. This indicates that living at higher elevations in the valley was no protection against the potential negative health impacts of the wildfire smoke that was transported into the city.
The report also briefly reviews the Air Quality Health Index (AQHI) and the AQHI+ and AQI indices. The formulation of the traditional AQHI (combined risks for NO2, O3 and PM2.5, with a heavier weighting towards NO2 and O3) is designed for large metropolitan areas and does not reflect the nature of air pollution issues in smaller B.C. communities, which may be heavily impacted by smoke and have relatively low levels of NO2 and O3.
There are additional concerns with the AQHI related to the establishment of appropriate warning systems when public health may be compromised by rapid rises of airborne particulate concentrations. Whether these situations are effectively dealt with by any of the current and proposed new indices needs to be examined further.
The above is released by Kamloops Physicians for a Healthy Environment. All past studies are on the website www.kphe.ca under “Resources” and “Media Releases and Reports.”