Ma Li, Zhang Ying, Lin Zhuohui, Zhou Ying, Yan Chao, Zhang Yusheng, Zhou Wenshuo, Ma Wei, Hua Chenjie, Li Xiaoxiao, Deng Chenjuan, Qi Yu, Dada Lubna, Li Hongyan, Bianchi Federico, Petäjä Tuukka, Kangasluoma Juha, Jiang Jingkun, Liu Sijin, Hussein Tareq, Kulmala Markku, Liu Yongchun
Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Finland.
Ecotoxicol Environ Saf. 2022 Sep 15;243:114023. doi: 10.1016/j.ecoenv.2022.114023. Epub 2022 Aug 26.
Ultrafine particles (UFPs) usually explosive growth during new particle formation (NPF) events. However, the risk of exposure to UFPs on NPF days has been ignored due to the prevalence of mass-based air quality standards. In this study, the daily deposited doses, i.e., the daily deposited particle number dose (D), mass dose (D), and surface area dose (D), of ambient particles in the human respiratory tract in Beijing were evaluated based on the particle number size distribution (3 nm-10 µm) from June 2018 to May 2019 utilizing a Multiple-Path Particle Dosimetry Model (MPPD) after the hygroscopic growth of particles in the respiratory tract had been accounted for. Our observations showed a high frequency (72.6%) of NPF on excellent air quality days, with daily mean PM concentrations less than 35 μg m. The daily D on excellent air quality days was comparable with that on polluted days, although the D on excellent air quality days was as low as 15.6% of that on polluted days. The D on NPF days was ~1.3 times that on non-NPF days. The D in respiratory tract regions decreased in the order: tracheobronchial (TB) > pulmonary (PUL) > extrathoracic (ET) on NPF days, while it was PUL > TB > ET on non-NPF days. The number of deposited nucleation mode particles, which were deposited mainly in the TB region (45%), was 2 times higher on NPF days than that on non-NPF days. Our results demonstrated that the deposition potential due to UFPs in terms of particle number concentrations is high in Beijing regardless of the aerosol mass concentration. More toxicological studies related to UFPs on NPF days, especially those targeting tracheobronchial and pulmonary impairment, are required in the future.
超细颗粒物（UFPs）通常在新粒子形成（NPF）事件期间呈爆发式增长。然而，由于基于质量的空气质量标准普遍存在，NPF日接触UFPs的风险一直被忽视。在本研究中，利用多路径粒子剂量模型（MPPD），基于2018年6月至2019年5月的粒子数粒径分布（3纳米 - 10微米），在考虑呼吸道中粒子吸湿增长后，评估了北京环境颗粒物在人体呼吸道中的每日沉积剂量，即每日沉积粒子数剂量（D）、质量剂量（D）和表面积剂量（D）。我们的观测结果显示，在空气质量优的日子里NPF出现频率很高（72.6%），当日平均PM浓度小于35微克/立方米。空气质量优的日子里的每日D与污染日相当，尽管空气质量优的日子里的D低至污染日的15.6%。NPF日的D约为非NPF日的1.3倍。在NPF日，呼吸道区域的D按以下顺序降低：气管支气管（TB）>肺部（PUL）>胸外（ET），而非NPF日则为PUL>TB>ET。主要沉积在TB区域（45%）的核模态粒子的沉积数量在NPF日比非NPF日高2倍。我们的结果表明，无论气溶胶质量浓度如何，北京UFPs在粒子数浓度方面的沉积潜力都很高。未来需要开展更多与NPF日UFPs相关的毒理学研究，尤其是针对气管支气管和肺部损伤的研究。
