Articles | Volume 17, issue 15
Research article
07 Aug 2017
Research article |  | 07 Aug 2017

Sources of particulate matter components in the Athabasca oil sands region: investigation through a comparison of trace element measurement methodologies

Catherine Phillips-Smith, Cheol-Heon Jeong, Robert M. Healy, Ewa Dabek-Zlotorzynska, Valbona Celo, Jeffrey R. Brook, and Greg Evans

Abstract. The province of Alberta, Canada, is home to three oil sands regions which, combined, contain the third largest deposit of oil in the world. Of these, the Athabasca oil sands region is the largest. As part of Environment and Climate Change Canada's program in support of the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring program, concentrations of trace elements in PM2. 5 (particulate matter smaller than 2.5 µm in diameter) were measured through two campaigns that involved different methodologies: a long-term filter campaign and a short-term intensive campaign. In the long-term campaign, 24 h filter samples were collected once every 6 days over a 2-year period (December 2010–November 2012) at three air monitoring stations in the regional municipality of Wood Buffalo. For the intensive campaign (August 2013), hourly measurements were made with an online instrument at one air monitoring station; daily filter samples were also collected. The hourly and 24 h filter data were analyzed individually using positive matrix factorization. Seven emission sources of PM2. 5 trace elements were thereby identified: two types of upgrader emissions, soil, haul road dust, biomass burning, and two sources of mixed origin. The upgrader emissions, soil, and haul road dust sources were identified through both the methodologies and both methodologies identified a mixed source, but these exhibited more differences than similarities. The second upgrader emissions and biomass burning sources were only resolved by the hourly and filter methodologies, respectively. The similarity of the receptor modeling results from the two methodologies provided reassurance as to the identity of the sources. Overall, much of the PM2. 5-related trace elements were found to be anthropogenic, or at least to be aerosolized through anthropogenic activities. These emissions may in part explain the previously reported higher levels of trace elements in snow, water, and biota samples collected near the oil sands operations.

Short summary
The sources of PM2.5 components exhibited short-term variabilities, and their contributions were identified in the Athabasca oil sands region. Much of the trace elements were found to originate from anthropogenic activities, i.e., oil sands upgrading and on- and off-road transportation. Some of these anthropogenic activities became better defined and understood only through highly time-resolved measurements, which can help guide further studies and policy decisions in the oil sands area.
Final-revised paper