Research Center for Atmospheric Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; Chongqing Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir, Chongqing Three Gorges University, Wanzhou, 404000, China.
School of Basic Medical Sciences, North Sichuan Medical College, Nanchong, 637000, Sichuan, China.
Chemosphere. 2020 Aug;252:126425. doi: 10.1016/j.chemosphere.2020.126425. Epub 2020 Mar 10.
Environmentally persistent free radicals (EPFRs) are a novel class of hazardous substances that can exist stably in airborne particles for a period ranging from days to weeks and are potentially toxic to human health. Electron paramagnetic resonance spectroscopy (EPR) was used to characterize particulate EPFRs in Wanzhou in the Three Gorges Reservoir area in 2017. During the whole of 2017, the average concentration of particulate EPFRs was 7.0 × 10 ± 1.7 × 10 spins/m. The seasonal concentration of EPFRs in PM showed a trend of autumn > winter > spring > summer. The maxima and minima of EPFRs occurred in spring with concentrations of 2.1 × 10 spins/m and 9.4 × 10 spins/m respectively. The EPFRs in PM were mainly carbon-centered radicals with adjacent oxygen atoms. Significant positive correlations were found between EPFRs and SO, NO and NH (r > 0.55, n = 111), indicating that EPFRs are associated with secondary sources. The atmospheric processing of particles from coal combustion, traffic, and agriculture were important sources of EPFRs. They were also particularly well correlated with K and Cl in winter, suggesting that EPFRs may also be derived from wintertime biomass burning emissions. The amount of inhalable EPFRs in Wanzhou was equivalent to the range of 2.3-6.8 cigarettes per capita per day. This study provides evidence of the potential health risks of EPFRs in PM, and references for air pollution control in the Three Gorges Reservoir area.
环境持久性自由基 (EPFRs) 是一类新型的危险物质，它们可以在空气颗粒物中稳定存在数天到数周，对人类健康具有潜在毒性。电子顺磁共振波谱 (EPR) 用于表征 2017 年三峡库区万州大气颗粒物中的 EPFRs。2017 年全年，颗粒物 EPFRs 的平均浓度为 7.0×10±1.7×10 自旋/m。PM 中 EPFRs 的季节浓度呈秋季>冬季>春季>夏季的趋势。EPFRs 的最大值和最小值出现在春季，浓度分别为 2.1×10 自旋/m 和 9.4×10 自旋/m。PM 中的 EPFRs 主要是带有相邻氧原子的碳中心自由基。EPFRs 与 SO、NO 和 NH 之间存在显著的正相关关系（r>0.55，n=111），表明 EPFRs 与二次源有关。煤燃烧、交通和农业产生的颗粒物的大气处理是 EPFRs 的重要来源。它们与冬季的 K 和 Cl 也特别相关，这表明 EPFRs 可能也来自冬季生物质燃烧排放。万州可吸入 EPFRs 的含量相当于每人每天 2.3-6.8 支香烟的范围。本研究为 PM 中 EPFRs 的潜在健康风险提供了证据，也为三峡库区的空气污染控制提供了参考。
