Canadian Oil Sands, which comprise 97% of Canada’s 176 billion barrels of proven oil reserves, are located beneath 140,200 km2 of boreal forests, prairies and wetlands, and are the second largest known deposit of crude oil in the world. As such, this region has experienced rapid industrial development, which resulted also in increasing industrial air emissions, primarily from bitumen upgrading and mine vehicle fleet operations. This rapid development has led to concerns regarding health risk to humans, and other terrestrial and aquatic wildlife associated with exposure to toxic contaminants, especially metals and polycyclic aromatic compounds (PACs) particularly along the Athabasca River and its watershed. Canada’s Minister of the Environment announced that Environment Canada (EC) will jointly lead, in collaboration with Government of Alberta and relevant stakeholders, the development and implementation of an enhanced monitoring system in the Oil Sands region to provide information on the state of the air, water, land andbiodiversity. This work presents preliminary data on the first assessment of elemental composition of fine particulate matter (particles<2.5 mm in diameter; PM2.5) at 3 air quality sites in close proximity to Oil Sands processing activities. Since December 2010, integrated 24 hour air samples were collected every sixth day on a 47-mm Teflon filters using Thermo Fisher Partisol 2000-FRM samplers operated by the National Air Pollution Surveillance (NAPS) network that involves EC and the Canadian provinces and territories. All samples including laboratory, travel and field blanks were subjected to gravimetric determination of PM2.5 mass and energy dispersive X-ray fluorescence (ED-XRF) analysis for 46 elements. Since ED-XRF is a non-destructive technique, PM2.5 samples were subsequently analyzed for 37 trace elements including rare earth elements using inductively-coupled plasma mass spectrometry (ICP-MS) combined with microwave-assisted acid digestion. The resulting data will be discussed.

The Canadian National Air Pollution Surveillance (NAPS) network, monitoring criteria gases (CO, O-3, NOx, and SO2), PM2.5, PM10, volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs) and particle chemical mass and composition, has been in operation for over 40 years. Since 1984 both fine (<2.5 mu m - PM2.5) and coarse (2.5-10 mu m PM10-2.5) particle mass measurements have been made at NAPS network sites using dichotomous samplers. In January 2003, the NAPS PM2.5 speciation program was initiated with the purpose of measuring all major components of PM2.5, including ammonium nitrate, ammonium sulphate, metals, and organic and elemental carbon. The present paper describes the improved sampling (e.g. Teflon/Nylon filter packs for nitrate loss, and an active blank for each and every sample in the determination of positive organic carbon artifacts), and analytical methods used in the Canadian NAPS PM2.5 speciation program. A detailed dataset was then analyzed for seasonal and geographical variations in the major components of 24-h time integrated PM2.5 samples collected at eight urban and three rural measurement sites across Canada (2003-2008). Chemical mass reconstruction was used for assessment of the adequacy of selected sampling and chemical parameters as well as for the determination of the relative contributions of different compound classes to PM2.5 mass. The highest frequency of PM2.5 episodes exceeding 30 mu g m(-3) were observed in Ontario and southern Quebec. In general, the most important contributions to PM2.5 mass were secondary aerosol sulphate and nitrate (38-63% for western sites and 3-44% for eastern sites), depending on the season. Organic matter (OM) was found to be the second most important component (21-45%), while particle-bound water (PBW) accounted for 6-12% of the PM2.5 mass. Golden B.C. was an exception, exhibiting high levels of OM (60-70%) and low levels of PBW (similar to 3%). Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.

Source apportionment of 24-hour integrated PM2.5 chemical speciation data, collected at five Canadian urban sites, Windsor, Toronto, Montreal, Halifax, and Edmonton was performed using the receptor model, Positive Matrix Factorization (PMF). In order to determine the influences of local and regional sources, in-depth wind direction and back trajectory analyses were performed using the conditional probability function (CPF) and the potential source contribution function (PSCF). The highest PM2.5 levels were observed in Windsor followed by Toronto and Montreal. Secondary sulfate and nitrate were the major factors contributing to the PM2.5 mass, accounting for 41% - 61% in the five sites. These secondary factors were associated with trans-boundary emissions from Ohio, Pennsylvania, and New York. An elemental carbon (EC)-rich factor was identified in Windsor, Toronto, and Montreal, characterized by distinct EC and organic carbon (OC) profiles. The EC-rich factor accounted for 6% - 19% of the total PM2.5 mass in summer and also appeared to be related to trans-boundary pollutants. The combined contributions of traffic and road dust ranged from 14% to 19%, with a portion of the nitrate factor also coming from vehicles. In Halifax, sea salt was the second strongest source, contributing 18% of the PM2.5. In Edmonton, strong correlation of volatile organic compounds with the major PM2.5 factors suggested that local industrial sources were significant sources of secondary aerosol. Further, biomass burning contributed 12% of the PM2.5 mass in Edmonton.Both local and regional sources were found to contribute at all sites. Thus, PM2.5 can be reduced at all the sites through local controls. However given the significant contribution of trans-boundary contributions to the PM2.5 mass, a substantial reduction of PM2.5 in four of the cities will also require agreements to limit the production and transport of trans-boundary pollutants. (C) Author(s) 2011. This work is distributed under the Creative Commons Attribution 3.0 License.