AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Long-term Trends of PM2.5 Sources at Metropolitan Areas in Canada: Identifying Factors that Contributed to Improved Air Quality
CHEOL-HEON JEONG, Kelly Sabaliauskas, Dennis Herod, Ewa Dabek-Zlotorzynska, Greg J. Evans, SOCAAR, University of Toronto
Abstract Number: 321 Working Group: Source Apportionment
Abstract One third of Canada’s population lives in or in the regions surrounding Toronto, Edmonton and Montreal. A source apportionment study in these three metropolitan areas was conducted based on the chemical characterization of PM2.5 collected from 2008 to 2014 and the use of a Positive Matrix Factorization (PMF). In order to provide a historical prospective on how PM2.5 has evolved and improved over the last decade, PMF was applied to 11-year comprehensive aerosol chemical speciation data from 2004 to 2014 in Toronto. A particular focus in Toronto was resolving the influences of reduced coal combustion emissions vs. the post-recession decline in industry and manufacturing in Canada and the USA. In Edmonton, the contribution of oil refining related sources was examined, given the increase in this industrial activity in the intermittent years. In Montreal, the focus was on emissions from wintertime biomass burning in support of municipal interventions being implemented. Secondary sulphate was found still to be the most important factor contributing to the PM2.5 mass in all of the cities. In Edmonton, secondary sulphate was associated with local sources, whereas long-range transport of emissions from coal combustion was the dominant factor in Toronto and Montreal. The influence of long-range transport sources appeared to have declined over the last decade in Toronto. Wintertime PM2.5 was identified as a major issue in Edmonton, arising from increases in the contributions of secondary sulphate, secondary nitrate, biomass burning, and industrial sources. In Montreal, winter time PM2.5 was also higher than in summer, with residential biomass burning still making a substantial contribution. Overall, the landscape of sources contributing to PM2.5 evolved substantially over this period. While the contributions from many traditional sources of PM2.5 declined over this period in all three cities, contributing to improved air quality, these reductions caused increased contributions new sources to emerge.