Warsaw University of Technology, Faculty of Building Services, Hydro and Environmental Engineering, 20 Nowowiejska Str., 00-653 Warsaw, Poland.
Institute of Environmental Engineering of the Polish Academy of Sciences, 34 M. Skłodowska-Curie Str., 41-819 Zabrze, Poland.
Sci Total Environ. 2020 Apr 15;713:136729. doi: 10.1016/j.scitotenv.2020.136729. Epub 2020 Jan 15.
For the purposes of this work, a first in Poland, full-year collection of daily PM (particulate matter with aerodynamic diameter smaller than 2.5 μm) samples was chemically analyzed to determine the contents of elemental and organic carbon, water-soluble inorganic ions and 21 minor and trace elements in PM in an urban background site in Warsaw. Annual mean PM concentration reached 18.8 μg/m, with the lowest levels in summer (11.5 μg/m on average) and the highest in winter (27.5 μg/m), with several episodes reaching over 80 μg/m. Strong seasonal differences were observed mainly for the contents of nitrate and secondary organic carbon (SOC), while sulphate showed the least variability. Secondary species constituted on average 45% of PM mass, suggesting large influence of regional and long-range transport of pollutants. Source apportionment with the use of positive matrix factorization (PMF) method, supported by the analysis of enrichment factors, led to identification of six main sources of PM origin: residential combustion (fresh & aged aerosol) (46% of PM mass), traffic exhaust (21%) and non-exhaust (10%) emissions, mineral dust/construction works (12%), high-temperature processes (8%) and steel processing (3%). Including primary organic carbon (POC) and SOC as two separate constituents helped to distinguish between the primary and secondary sources of the aerosol. The identification of sources was also supported by investigating their yearly and weekly profiles, as well as the correlation of PM constituents with meteorological conditions, which are one of the main drivers of heat generation activities. We found that the most distinctive markers of PM sources in Warsaw are SOC, Cl and As for residential combustion, NH, Sb and POC for road transport, Ca and Mg for construction works and SO for long-range transport of PM.
这项工作在波兰尚属首次，对全年的每日 PM（空气动力学直径小于 2.5μm 的颗粒物）样本进行了全面采集，并进行了化学分析，以确定华沙城市背景点 PM 中元素碳和有机碳、水溶性无机离子以及 21 种痕量和微量元素的含量。年平均 PM 浓度达到 18.8μg/m，夏季浓度最低（平均为 11.5μg/m），冬季最高（27.5μg/m），有几次浓度超过 80μg/m。主要观察到硝酸盐和二次有机碳（SOC）含量存在明显的季节性差异，硫酸盐的变化最小。二次物质平均占 PM 质量的 45%，表明污染物的区域和长距离传输有较大影响。使用正矩阵因子化（PMF）方法进行源分配，并结合富集因子分析，确定了 PM 来源的六个主要来源：居民燃烧（新鲜和老化的气溶胶）（占 PM 质量的 46%）、交通尾气（21%）和非尾气（10%）排放、矿物粉尘/建筑工程（12%）、高温过程（8%）和钢铁加工（3%）。将原始有机碳（POC）和 SOC 作为两个单独的成分包含在内，有助于区分气溶胶的原始和次生来源。通过研究其年度和每周的分布情况，以及 PM 成分与气象条件的相关性，也有助于识别污染源，气象条件是产生热量活动的主要驱动因素之一。我们发现，华沙 PM 来源的最显著特征标志物是居民燃烧的 SOC、Cl 和 As，道路交通的 NH、Sb 和 POC，建筑工程的 Ca 和 Mg，以及长距离传输的 SO。
