Tian Linhui, Woo Wonsik, Lin Ying-Hsuan
Department of Environmental Sciences, University of California, Riverside, California 92521, United States.
Environmental Toxicology Graduate Program, University of California, Riverside, California 92521, United States.
Chem Res Toxicol. 2025 Feb 17;38(2):260-269. doi: 10.1021/acs.chemrestox.4c00402. Epub 2025 Jan 20.
E-cigarette emissions, which contain a variety of hazardous compounds, contribute significantly to indoor air pollution and raise concerns about secondhand exposure to vaping byproducts. Compared to fresh vape emissions, our understanding of chemically aged products in indoor environments remains incomplete. Terpenes are commonly used as flavoring agents in e-liquids, which have the ability to react with the dominant indoor oxidant ozone (O) to produce reactive oxygenated byproducts and result in new particle formation. In this study, mixtures of propylene glycol (PG), vegetable glycerin (VG), and terpenes as e-liquids were injected into a 2 m FEP chamber to simulate the indoor aging process. 100 ppbv O was introduced into the chamber and allowed to react with the fresh vape emissions for 1 h. Complementary online and offline analytical techniques were used to characterize the changes in the aerosol size distribution and chemical composition during the aging processes. We observed more ultrafine particles and a greater abundance of highly oxygenated species, such as carbonyls, in aged e-cigarette aerosols. Compared with their fresh counterparts, the aged emissions exhibited greater cytotoxic potential, which can be attributed to the formation of these highly oxygenated compounds that are not present in the fresh emissions. This work highlights the dynamic chemistry and toxicity of e-cigarette aerosols in the indoor environment as well as the indirect risks of secondhand exposure.
电子烟排放物含有多种有害化合物，对室内空气污染有显著影响，并引发了对二手接触电子烟副产品的担忧。与新鲜的电子烟排放物相比，我们对室内环境中化学老化产品的了解仍不完整。萜烯通常用作电子烟液中的调味剂，它能够与室内主要氧化剂臭氧（O）发生反应，产生活性氧化副产品并导致新颗粒的形成。在本研究中，将丙二醇（PG）、蔬菜甘油（VG）和萜烯的混合物作为电子烟液注入一个2米长的氟化乙烯丙烯共聚物（FEP）腔室中，以模拟室内老化过程。向腔室内引入100 ppbv的臭氧，并使其与新鲜的电子烟排放物反应1小时。使用互补的在线和离线分析技术来表征老化过程中气溶胶粒径分布和化学成分的变化。我们观察到，老化的电子烟气溶胶中有更多的超细颗粒和大量高氧化态物质，如羰基化合物。与新鲜的电子烟排放物相比，老化排放物表现出更大的细胞毒性潜力，这可归因于新鲜排放物中不存在的这些高氧化态化合物的形成。这项工作突出了室内环境中电子烟气溶胶的动态化学和毒性以及二手接触的间接风险。
