Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, 116023, China.
Environ Sci Pollut Res Int. 2022 Apr;29(17):24612-24622. doi: 10.1007/s11356-021-17688-9. Epub 2021 Nov 25.
Environmentally persistent free radicals (EPFRs) are an emerging class of environmental hazardous contaminants that extensively, stably exist in airborne particulate matter and pose harmful effects on human health. However, there was little research about the sources of EPFRs in actual atmospheric conditions. This study reported the occurrence, characteristics, and sources of EPFRs and polycyclic aromatic hydrocarbons (PAHs) in PM collected in Dalian, China. The concentrations of PM-bound EPFRs ranged from 1.13 × 10 to 8.97 × 10 spins/m (mean value: 1.14 × 10 spins/m). Carbon-centered radicals and carbon-centered radicals with adjacent oxygen atoms were detected. The concentration of ∑PAHs ranged from 1.09 to 76.24 ng/m, and PAHs with high molecular weight (HMW) were predominant species in PM. Correlation of EPFRs with SO, NO, O, and 12 kinds of PAHs indicated that both fuel (coal and biomass) combustion and photoreaction in atmosphere influenced the concentrations of EPFR. The positive matrix factorization (PMF) model results have shown that the primary sources contributed most of the EPFRs and those of secondary sources had a little proportion. Coal combustion (52.4%) was the primary contributor of EPFRs, followed by traffic emission (22.6%), industrial sources (9.6%), and secondary sources (9.2%) during the heating period, whereas industrial emission (39.2%) was the primary contributor, followed by coal combustion (38.1%), vehicular exhaust (23.5%), and secondary sources (9.6%) during the non-heating period. The finding of the present study provides an important evidence for further study on the formation mechanism of EPFRs in actual atmospheric to control the air pollution.
环境持久性自由基（EPFRs）是一类新兴的环境有害污染物，广泛、稳定地存在于空气中的颗粒物中，对人类健康造成有害影响。然而，在实际大气条件下，关于 EPFRs 的来源的研究很少。本研究报道了在中国大连采集的 PM 中 EPFRs 和多环芳烃（PAHs）的发生、特征和来源。PM 结合的 EPFRs 的浓度范围为 1.13×10 到 8.97×10 自旋/m（平均值：1.14×10 自旋/m）。检测到碳中心自由基和含有相邻氧原子的碳中心自由基。∑PAHs 的浓度范围为 1.09 到 76.24ng/m，高分子量（HMW）PAHs 是 PM 中的主要物种。EPFRs 与 SO、NO、O 和 12 种 PAHs 的相关性表明，燃料（煤和生物质）燃烧和大气光化学反应都影响了 EPFRs 的浓度。正定矩阵因子分解（PMF）模型结果表明，主要来源对 EPFRs 的贡献最大，二次来源的比例较小。在供暖期，煤燃烧（52.4%）是 EPFRs 的主要来源，其次是交通排放（22.6%）、工业源（9.6%）和二次源（9.2%），而在非供暖期，工业排放（39.2%）是主要来源，其次是煤燃烧（38.1%）、车辆尾气（23.5%）和二次源（9.6%）。本研究的发现为进一步研究实际大气中 EPFRs 的形成机制以控制空气污染提供了重要证据。
