PM2.5在7年期间(2013-2019年)在安大略省南部相距50公里的两个地点进行了采样(同时为5年:2015-2019年)。一个是高度工业化的网站(汉密尔顿),而另一个是农村地区(Simcoe)。为了评估工业化对影响这两个地点空气质量的PM组成和来源的影响,正矩阵分解结合色散归一化(DN-PMF)用于识别Simcoe和Hamilton的六个和八个因子,分别。按PM质量贡献递减顺序的Simcoe因子为:颗粒硫酸盐(pSO4),次级有机气溶胶(SOA),地壳物质,颗粒硝酸盐(pNO3),生物质燃烧,和车辆排放。在汉密尔顿,工业化的影响是通过研究期间环境PM2.5平均浓度高出36%以及冶金特有因素的存在观察到的,即,焦化和炼钢,与Simcoe相比.焦化和炼钢因素对汉密尔顿的PM质量贡献约15%。使用适当的非参数趋势测试的季节性变体以及相关斜率(Sen's)来评估随时间变化的PM2.5因子贡献的统计学显着变化。特别是在汉密尔顿,注意到焦化的PM贡献显着下降(-0.03μg/m3/yr或-4.1%/yr),而炼钢在研究期间没有统计学上的显着下降。在研究期间,汉密尔顿的其他因素显示出统计学上的显着下降,包括:pSO4(-0.27μg/m3/yr或-12.6%/yr),生物质燃烧(-0.05微克/立方米/年或-9.02%/年),地壳物质(-0.03微克/立方米/年或-5.28%/年)。这些因素主要导致了研究期间PM2.5的显着下降(-0.35μg/m3/yr或-4.24%/yr)。这项工作表明了长期监测在评估工业化对类似受影响地区空气质量的独特贡献和时间变化方面的重要性。
PM2.5 was sampled over a seven-year period (2013-2019) at two locations ∼50 km apart in Southern Ontario (concurrently for five years: 2015-2019). One is a heavily industrialized site (
Hamilton), while the other was a rural site (Simcoe). To assess the impact of industrialization on the composition and sources of PM affecting air quality in these two locations, positive matrix factorization coupled with dispersion normalization (DN-PMF) was used to identify six and eight factors at Simcoe and Hamilton, respectively. The Simcoe factors in order of diminishing PM mass contribution were: particulate sulphate (pSO4), secondary organic aerosol (SOA), crustal matter, particulate nitrate (pNO3), biomass burning, and vehicular emissions. At
Hamilton, the effects of industrialization were observed by the ∼36% higher average ambient PM2.5 concentration for the study period as well as the presence of factors unique to metallurgy, i.e., coking and steelmaking, compared to Simcoe. The coking and steelmaking factors contributed ∼15% to the PM mass at
Hamilton. Seasonal variants of appropriate nonparametric trend tests with the associated slopes (Sen\'s) were used to assess statistically significant changes in the factor contributions to PM2.5 over time. Specifically at
Hamilton, a significant decline in PM contributions was noted for coking (-0.03 μg/m³/yr or -4.1%/yr) while steelmaking showed no statistically significant decline over the study period. Other factors at
Hamilton that showed statistically significant declines over the study period were: pSO4 (-0.27 μg/m³/yr or -12.6%/yr), biomass burning (-0.05 μg/m³/yr or -9.02%/yr), crustal matter (-0.03 μg/m³/yr or -5.28%/yr). These factors mainly accounted for the significant decline in PM2.5 over the study period (-0.35 μg/m³/yr or -4.24%/yr). This work shows the importance of long-term monitoring in assessing the unique contributions and temporal changes of industrialization on air quality in Ontario and similarly affected locations.