Yang Weiqiang, Liao Chenghao, Peng Chao, Wu Zhenfeng, Pei Chenglei, Yu Qingqing, Wang Jun, Zhang Jinpu, Ye Chenshuo, Zhang Yanli, Zhang Yongbo, Wang Xinming
Guangdong Provincial Academy of Environmental Science, Guangzhou, 510045, China; State Key Laboratory of Advanced Environmental Technology, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; Joint Lab for Atmospheric Photochemistry, Guangdong-Hong Kong-Macau Center for Eco-Environmental Sciences, Guangzhou, 510045, China.
Guangdong Provincial Academy of Environmental Science, Guangzhou, 510045, China; State Key Laboratory of Advanced Environmental Technology, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; Joint Lab for Atmospheric Photochemistry, Guangdong-Hong Kong-Macau Center for Eco-Environmental Sciences, Guangzhou, 510045, China.
Environ Pollut. 2025 Sep 15;381:126648. doi: 10.1016/j.envpol.2025.126648. Epub 2025 Jun 9.
Aromatic hydrocarbons (AHs) are both hazardous air pollutants and key precursors of ozone (O) and secondary organic aerosols. Understanding the relationship between AHs and O is essential for formulating targeted O episode control, as AHs exhibit the highest mitigation potential among volatile organic compounds (VOCs). Here, we conducted online monitoring of AHs at an urban site in the Pearl River Delta (PRD) region to characterize AHs, identify their sources, and assess their association with O in support of O control strategies. The average total mixing ratio of AHs was 6.95 ± 0.51 ppbv during the observation. On O episode days, AHs were 44.1 % higher than on non-O episode days due to elevated nighttime levels. Positive matrix factorization identified solvent use, vehicle exhaust, and biomass burning as the major sources of AHs, contributing 38.1 %, 23.7 % and 19.8 %, respectively. Cutting solvent use emission was found to be the most effective approach for lowing ambient AHs and reactive species levels, as its accounted for 51.5 %, 51.3 % and 70.7 % of elevated AHs, toluene and xylenes levels during O episode days compared to non-O episode days. Three O sensitivity types were identified based on relative incremental reactivity (RIR) and empirical kinetic modeling approach (EKMA) analyses for O episode days. Anthropogenic VOCs with the top RIR-weighted concentration were toluene, m/p-xylene, and o-xylene during both O and non-O episode days. The analysis of various reduction schemes for three O sensitivity types indicate that either AHs or NOx reductions can lead a rapid short-term decline in O level, while NOx-focused control strategies offer sustained O reduction under minimum collaborative reduction schemes of AHs and NOx in the long-term.
芳香烃（AHs）既是有害空气污染物，也是臭氧（O₃）和二次有机气溶胶的关键前体物。了解AHs与O₃之间的关系对于制定有针对性的O₃污染事件控制措施至关重要，因为在挥发性有机化合物（VOCs）中，AHs具有最高的减排潜力。在此，我们在珠江三角洲（PRD）地区的一个城市站点对AHs进行了在线监测，以表征AHs的特征、确定其来源，并评估它们与O₃的关联，以支持O₃控制策略。观测期间，AHs的平均总混合比为6.95±0.51 ppbv。在O₃污染事件发生日，由于夜间浓度升高，AHs比非O₃污染事件发生日高出44.1%。正定矩阵因子分解法确定溶剂使用、机动车尾气排放和生物质燃烧是AHs的主要来源，分别占38.1%、23.7%和19.8%。发现削减溶剂使用排放是降低环境中AHs和活性物种水平的最有效方法，因为与非O₃污染事件发生日相比，在O₃污染事件发生日，其分别占AHs、甲苯和二甲苯浓度升高量的51.5%、51.3%和70.7%。基于相对增量反应活性（RIR）和经验动力学建模方法（EKMA）对O₃污染事件发生日进行分析，确定了三种O₃敏感性类型。在O₃污染事件发生日和非O₃污染事件发生日，RIR加权浓度最高的人为VOCs均为甲苯、间/对二甲苯和邻二甲苯。对三种O₃敏感性类型的各种减排方案分析表明，减少AHs或氮氧化物（NOx）均可导致O₃水平在短期内迅速下降，而从长期来看，在AHs和NOx的最低协同减排方案下，以NOx为重点的控制策略能使O₃持续降低。
