State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
Sci Total Environ. 2022 Mar 25;814:151954. doi: 10.1016/j.scitotenv.2021.151954. Epub 2021 Nov 27.
To gain a comprehensive understanding of sources, health risks, and regional transport of PM-bound metals in Beijing, one-year continuous measurement (K, Fe, Ca, Zn, Pb, Mn, Ba, Cu, As, Se, Cr, and Ni) was conducted from December 2016 to November 2017 and Positive Matrix Factorization analysis (PMF) was applied for source apportionment. It was found that the seasonal variation of sources could vary significantly among metals. Sources of Ca, Ba, As, Se, and Cr did not show much seasonal variations, with the contribution of its predominant source higher than 35% in each season. However, the major sources of K, Fe, Zn, Pb, Mn, Cu, and Ni exhibited obvious seasonal variations. In addition, the characteristics of metals in haze episodes were comprehensively investigated. Haze episodes in Beijing were characterized by higher metal concentrations and health risks, which were about 2- 6 times higher than non-haze periods. Moreover, the types of haze episode were different in winter and spring. Haze episodes in winter were mostly influenced by coal combustion, the contribution of which increased greatly and accounted for about 30% of PM. The metals such as K, Zn, Pb, As, and Se significantly increased, which were mainly transported from south of Beijing. During haze episodes in spring, dust was an important source, which contributed to higher concentrations of crustal metals that transported from northwest of Beijing. To quickly and effectively identify source regions of metals in Beijing during haze episodes, a new diagnostic ratio method using Ca as a reference was developed. The ratios of some anthropogenic metals to Ca significantly increased when air mass was mainly from south of Beijing during haze episodes while the ratios remained constantly low in non-haze periods, when local emissions dominated. This method could be useful for rapid identification and control of metal pollution in Beijing.
为全面了解北京 PM 中金属元素的来源、健康风险和区域传输，本研究于 2016 年 12 月至 2017 年 11 月进行了为期一年的连续测量（K、Fe、Ca、Zn、Pb、Mn、Ba、Cu、As、Se、Cr 和 Ni），并应用正定矩阵因子分析（PMF）进行源解析。研究发现，不同金属的季节性变化差异较大。Ca、Ba、As、Se 和 Cr 的来源在各个季节变化不大，其主要来源的贡献在每个季节都高于 35%。然而，K、Fe、Zn、Pb、Mn、Cu 和 Ni 的主要来源表现出明显的季节性变化。此外，本研究还全面调查了霾事件中金属的特征。北京霾事件的特点是金属浓度和健康风险较高，分别是非霾期的 2-6 倍。此外，冬季和春季霾事件的特征也不同。冬季霾事件主要受煤燃烧影响，其贡献大大增加，约占 PM 的 30%。K、Zn、Pb、As 和 Se 等金属显著增加，主要从北京南部传输而来。春季霾事件中，扬尘是一个重要来源，导致来自北京西北部的地壳金属浓度升高。为了快速有效地识别霾事件中北京金属的源区，本研究开发了一种新的以 Ca 为参比的诊断比方法。当霾事件期间空气主要来自北京南部时，一些人为金属与 Ca 的比值显著增加，而在非霾期本地排放为主时，比值保持较低。该方法可用于快速识别和控制北京的金属污染。
Zotero 插件