Department of Epidemiology, Biostatistics and Occupational Health , McGill University , Montreal , Quebec H3A 1A2 , Canada.
Air Health Science Division , Health Canada , Ottawa , Ontario K1A 0K9 , Canada.
Environ Sci Technol. 2019 Mar 5;53(5):2799-2810. doi: 10.1021/acs.est.8b05543. Epub 2019 Feb 20.
Few studies have characterized within-city spatial variations in the oxidative potential of fine particulate air pollution (PM). In this study, we evaluated multiple measures of PM oxidative potential across Toronto, Canada (2016-2017), including glutathione/ascorbate-related oxidative potential (OP and OP) and dithiothreitol depletion (OP). Integrated 2-week samples were collected from 67 sites in summer and 42 sites in winter. Multivariable linear models were developed to predict OP based on various land use/traffic factors, and PM metals and black carbon were also examined. All three measures of PM oxidative potential varied substantially across Toronto. OP and OP were primarily associated with traffic-related components of PM (i.e., Fe, Cu, and black carbon) whereas OP was not a strong marker for traffic during either season. During summer, multivariable models performed best for OP ( R = 0.48) followed by OP ( R = 0.32) and OP ( R = 0.22). During winter, model performance was best for OP ( R = 0.55) followed by OP ( R = 0.50) and OP ( R = 0.23). Model parameters varied between seasons, and between-season differences in PM mass concentrations were weakly/moderately correlated with seasonal differences in OP. Our findings highlight substantial within-city variations in PM oxidative potential. More detailed information is needed on local sources of air pollution to improve model performance.
很少有研究描述过城市内细颗粒物空气污染（PM）的氧化潜力的空间变化。在这项研究中，我们评估了加拿大多伦多市（2016-2017 年）的多种 PM 氧化潜力指标，包括谷胱甘肽/抗坏血酸相关的氧化潜力（OP 和 OP）和二硫苏糖醇消耗（OP）。夏季从 67 个地点和冬季从 42 个地点采集了综合两周的样本。建立了多变量线性模型，以根据各种土地利用/交通因素预测 OP，还研究了 PM 金属和黑碳。多伦多市的三种 PM 氧化潜力指标差异很大。OP 和 OP 主要与 PM 中与交通有关的成分（即 Fe、Cu 和黑碳）有关，而 OP 无论是在夏季还是冬季都不是交通的有力标志。在夏季，OP 的多变量模型表现最佳（ R = 0.48），其次是 OP（ R = 0.32）和 OP（ R = 0.22）。在冬季，OP 的模型表现最佳（ R = 0.55），其次是 OP（ R = 0.50）和 OP（ R = 0.23）。模型参数在季节之间有所不同，PM 质量浓度的季节差异与 OP 的季节差异呈弱/中度相关。我们的研究结果突出了 PM 氧化潜力在城市内的巨大变化。需要更多关于空气污染本地来源的详细信息，以提高模型性能。
