Air Quality Processes Research Section, Air Quality Research Division, Environment and Climate Change Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada.
Dalla Lana School of Public Health and Department of Chemical Engineering and Applied Chemistry, University of Toronto, 223 College Street, Toronto, Ontario M5T 1R4, Canada.
Environ Sci Technol. 2020 Dec 1;54(23):14936-14945. doi: 10.1021/acs.est.0c06055. Epub 2020 Nov 13.
An "event-based" approach to characterize complex air pollutant mixtures was applied in the Oil Sands region of northern Alberta, Canada. This approach was developed to better-inform source characterization and attribution of the air pollution in the Indigenous community of Fort McKay, within the context of the lived experience of residents. Principal component analysis was used to identify the characteristics of primary pollutant mixtures, which were related to hydrocarbon emissions, fossil fuel combustion, dust, and oxidized and reduced sulfur compounds. Concentration distributions of indicator compounds were used to isolate sustained air pollution "events". Diesel-powered vehicles operating in the mines were found to be an important source during NO events. Industry-specific volatile organic compound (VOC) profiles were used in a chemical mass balance model for source apportionment, which revealed that nearby oil sands operations contribute to 86% of the total mass of nine VOC species (2-methylpentane, hexane, heptane, octane, benzene, toluene, ,-xylene, -xylene, and ethylbenzene) during VOC events. Analyses of the frequency distribution of air pollution events indicate that Fort McKay is regularly impacted by multiple mixtures simultaneously, underscoring the limitations of an exceedance-based approach relying on a small number of air quality standards as the only tool to assess risk.
一种“基于事件”的方法被应用于加拿大阿尔伯塔省北部的油砂地区，以描述复杂的空气污染物混合物。这种方法是为了更好地描述污染源特征，并在居民的生活体验背景下，确定 Fort McKay 原住民社区空气污染的归因。主成分分析用于识别主要污染物混合物的特征，这些特征与碳氢化合物排放、化石燃料燃烧、灰尘以及氧化和还原硫化合物有关。指示化合物的浓度分布用于分离持续的空气污染“事件”。研究发现，在 NO 事件期间，矿区运行的柴油动力车辆是一个重要的污染源。在化学质量平衡模型中使用了特定于行业的挥发性有机化合物 (VOC) 谱图进行源分配，结果表明，附近的油砂作业对九种 VOC 物种（2-戊烷、己烷、庚烷、辛烷、苯、甲苯、二甲苯、间二甲苯、对二甲苯和乙苯）的总质量贡献了 86%。对空气污染事件频率分布的分析表明，Fort McKay 经常受到多种混合物的同时影响，这突显了基于超标方法的局限性，该方法仅依靠少数空气质量标准作为评估风险的唯一工具。
