瑞典Paul Scherrer研究所Imad El Haddad团队揭示了欧洲主要通过第二代氧化产生人为有机气溶胶。相关论文于2025年3月10日发表在《自然—地球科学》杂志上。
暴露于人为大气气溶胶是一个主要的健康问题，每年在全球范围内造成数百万人死亡。交通和木材燃烧产生的芳香烃的氧化是次生有机气溶胶中低挥发性物种的重要人为来源，特别是在严重污染的环境中。目前尚不清楚人为次生有机气溶胶的形成是否主要涉及快速自氧化、较慢的连续氧化步骤或两者的结合。
研究组在欧洲核研究组织的“宇宙射线室外液滴实验”室中再现了一个典型的城市雾霾，并在分子水平上观察了二次有机气溶胶生长过程中芳香氧化产物的动态，以确定其产生和去除的机制。结果证明，连续氧化是形成大量二次有机气溶胶所必需的。第二代氧化使产品的饱和蒸汽压降低了几个数量级，并在典型的大气浓度下将芳香族二次有机气溶胶的产量从百分之几增加到百分之几十。通过区域建模，研究组发现欧洲70%以上的人为有机气溶胶暴露源于第二代氧化。
附：英文原文
Title: Anthropogenic organic aerosol in Europe produced mainly through second-generation oxidation
Author: Xiao, Mao, Wang, Mingyi, Mentler, Bernhard, Garmash, Olga, Lamkaddam, Houssni, Molteni, Ugo, Simon, Mario, Ahonen, Lauri, Amorim, Antonio, Baccarini, Andrea, Bauer, Paulus Salomon, Chen, Dexian, Chiu, Randall, Dada, Lubna, Duplissy, Jonathan, Finkenzeller, Henning, Fischer, Lukas, He, Xu-Cheng, Heinritzi, Martin, Hofbauer, Victoria, Kim, Changhyuk, Krten, Andreas, Kvashnin, Aleksandr, Lehtipalo, Katrianne, Liu, Yuliang, Mai, Huajun, Makhmutov, Vladimir, Mathot, Serge, Mauldin, Roy, Onnela, Antti, Petj, Tuukka, Qulver, Lauriane L. J., Rissanen, Matti, Schuchmann, Simone, Sipil, Mikko, Stolzenburg, Dominik, Stozhkov, Yuri, Tauber, Christian, Tom, Antnio, Wagner, Robert, Yan, Chao, Yang, Boxing, Ye, Penglin, Zha, Qiaozi, Curtius, Joachim, Hansel, Armin, Kirkby, Jasper, Kulmala, Markku, Volkamer, Rainer, Winkler, Paul M., Worsnop, Douglas R., Nie, Wei, Donahue, Neil M., Hoyle, Christopher R., Jiang, Jianhui, Baltensperger, Urs, Dommen, Josef, El Haddad, Imad
Issue&Volume: 2025-03-10
Abstract: Exposure to anthropogenic atmospheric aerosol is a major health issue, causing several million deaths per year worldwide. The oxidation of aromatic hydrocarbons from traffic and wood combustion is an important anthropogenic source of low-volatility species in secondary organic aerosol, especially in heavily polluted environments. It is not yet established whether the formation of anthropogenic secondary organic aerosol involves mainly rapid autoxidation, slower sequential oxidation steps or a combination of the two. Here we reproduced a typical urban haze in the ‘Cosmics Leaving Outdoor Droplets’ chamber at the European Organization for Nuclear Research and observed the dynamics of aromatic oxidation products during secondary organic aerosol growth on a molecular level to determine mechanisms underlying their production and removal. We demonstrate that sequential oxidation is required for substantial secondary organic aerosol formation. Second-generation oxidation decreases the products’ saturation vapour pressure by several orders of magnitude and increases the aromatic secondary organic aerosol yields from a few percent to a few tens of percent at typical atmospheric concentrations. Through regional modelling, we show that more than 70% of the exposure to anthropogenic organic aerosol in Europe arises from second-generation oxidation.
DOI: 10.1038/s41561-025-01645-z
Source: https://www.nature.com/articles/s41561-025-01645-z