By MICHAEL D. MEHTA, Ph.D.
One of the key lessons learned in recent months as a result of forest fires in the interior of British Columbia is that air pollution levels, and the monitoring of them by standard provincial approaches, woefully underestimates the range, diversity, intensity, and dispersion of PM2.5 sized particles at the community-level.
In Kamloops, it became clear during the months of July, August and early September of 2017 that this region has multiple air sheds rather than the more orthodox interpretation of homogeneity and uniformity.
This insight is based primarily on data collected by a network of more than 30 real-time, distributed sensors in the community made by PurpleAir. Additionally, air shed modelling and the impacts of proposed projects like the Ajax Mine require more scrutiny and new analyses to take into account lessons learned during the Summer of 2017.
The PurpleAir sensor network in Kamloops is a citizen science project. Since the Fall of 2016, sensors have been providing data in this region. The sensors report data every 20 seconds and this data is archived.
This network provides greater spatial and temporal resolution than the existing two provincial monitoring stations located in Kamloops. Although it’s clear that the accuracy of the PurpleAir sensors is off by up to 10% depending on conditions and level of particulates, this network shows trends and differences in a relative way that provincial monitors cannot provide.
The PurpleAir network also shows the effect of topography on air pollution levels, and the monitoring of wood smoke from forest fires demonstrated clearly how particulate matter concentrations tended to collect in lower elevations including the downtown and north shore areas. It also took longer for pollution levels to disperse in these locations then at higher altitudes.
The Summer of 2017 provides us with several other lessons about the complexity of air sheds in Kamloops that need to be considered if new industrial projects are likely to contribute to overall community-level air pollution.
First, air pollution is relatively democratic and it has well-established biological effects on human health and well-being that cross all strata of society. The medical and scientific evidence is clear that exposure to PM2.5 particles increases risk in a linear manner, and that there exists no safe level of exposure.
Although the young, elderly, and those with respiratory problems have a more profound impact when exposed to high levels of air pollution, it is likely that the majority of people in the region experienced some elevated level of risk. An increase in heart attack and stroke rates is the quintessential outcome of exposure to particulate pollution.
With it predicted that forest fires are likely to become more common and extreme in future years, and with the presence of other major polluters in the region including an active pulp and paper operation, the addition of new sources of air pollution at the magnitude expected from operation of the Ajax Mine will undoubtedly increase risk in the region and increase morbidity and mortality rates.
The costs to the community are significant in terms of lost economic output from illness, reduced quality of life, impacts on families and the community, increased health care expenses, and the loss of life itself.
Second, air quality modelling and predictions of harm at the community level often average out differences over time and space that inadequately capture real-world exposures and geographical differences.
The PurpleAir network shows clearly that air pollution is complex, constantly changing, and fickle. That said, there are differences in how air pollution is distributed in a community with a complex topography, variable wind patterns, temperature differences, and other features.
Kamloops should be one of the last places in British Columbia to site an open pit mine based on these characteristics, and the risk posed by additions to existing particulate levels is disproportionate to any benefit. The Ajax Mine is a prime example of something called private benefit-public risk.
Third, air quality in the region is likely to continue a downward spiral if the Ajax Mine is approved. It is important to recognize the cumulative effects in a community that already has several large industrial polluters, an active rail system running through the heart of the city with diesel emissions creating noticeable spikes in pollution downtown, highways, and other pollution sources including slash burning, residential wood burning practices, and forest fires.
There is even some discussion about including district heating at Thompson Rivers University to displace the use of natural gas with wood pellets. The cumulative effects of these multiple sources of air pollution are extremely difficult to model, yet it is clear that more pollution will add to the problem.
During the Summer of 2017, the Domtar Pulp Mill continued its daily operations even while PM2.5 levels spiked at over 600 micrograms/m3. These levels are many times higher than provincial targets, and represent a level of risk that exceeds by three times the level when cities like Beijing issue “red alert” days to limit vehicular traffic, curtail industrial operations temporarily, and warn the public about limiting activity and taking protective actions.
This did not happen in Kamloops during the Summer of 2017, and it seems unlikely that under the current regulatory environment that anything would be done to stop operations at an active Ajax Mine either. This represents a perfect storm during these kinds of situations, but more importantly higher pollution levels throughout the year affect the health of people on an ongoing basis making sudden increases in pollution levels even more impactful.
In short, the environmental impact assessment of the Ajax Mine is inadequate and incomplete. It fails to fully model air sheds based on new information and new technologies that provide better spatial and temporal resolution. This assessment also fails to include cumulative effects and other factors mentioned above.
The conclusion that the proposed mine will have no observed effects on air pollution, and by inference on human health, is not supported by current science, medical evidence, or even common sense.
Dr. Mehta is a Professor of Geography and Environmental Studies at Thompson Rivers University. He specializes in science, technology and society with a focus on environmental and health risk issues.