Secondhand electronic cigarette (e-cigarette) aerosol (SHA) might impair indoor air quality and expose bystanders. This study aims to investigate exposure to SHA in controlled conditions of enclosed settings simulating real-world scenario. An experiment was performed in a car and in a room, in which SHA was generated during a 30-minute ad libitum use of an e-cigarette. The experiment was replicated on five consecutive days in each setting. We measured PM_2.5, airborne nicotine concentrations, and biomarkers of exposure to SHA, such as nicotine metabolites, tobacco-specific nitrosamines, propylene glycol, and glycerol in bystanders’ saliva samples before, during, and after the exposure period. Self-reported health symptoms related to exposure to SHA were also recorded. The results showed that the highest median PM_2.5 concentration was recorded during the exposure period, being 21 µg/m³ in the room setting and 16 µg/m³ in the car setting—about twofold increase compared to the baseline. Most concentrations of the airborne nicotine and all biomarkers were below the limit of quantification in both settings. Bystanders in both settings experienced some short-term irritation symptoms, expressed as dry throat, nose, eyes, and phlegm. In conclusion, short-term use of an e-cigarette in confined spaces increased indoor PM_2.5 level and caused some irritation symptoms in bystanders.

中文翻译：

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密闭空间内电子烟二手气溶胶的环境和个人暴露：来自 TackSHS 项目的结果†

二手电子烟（电子烟）气溶胶 (SHA) 可能会损害室内空气质量并暴露旁观者。本研究旨在调查在模拟真实世界场景的封闭环境的受控条件下暴露于 SHA。在汽车和房间中进行了一项实验，其中在随意使用电子烟30 分钟期间产生了 SHA 。在每个设置中连续五天重复实验。我们测量了 PM _2.5、空气传播的尼古丁浓度以及暴露于 SHA 的生物标志物，例如暴露期间之前、期间和之后旁观者唾液样本中的尼古丁代谢物、烟草特异性亚硝胺、丙二醇和甘油。还记录了与暴露于 SHA 相关的自我报告的健康症状。结果表明，在暴露期间记录的PM _2.5中位数浓度最高，在室内环境中为 21 µg/m ³，在室内设置为 16 µg/m ³在汽车设置中 - 与基线​​相比增加了大约两倍。在这两种情况下，空气中尼古丁和所有生物标志物的大多数浓度都低于定量限。两种环境中的旁观者都经历了一些短期刺激症状，表现为喉咙、鼻子、眼睛和痰干。总之，在密闭空间内短期使用电子烟会增加室内 PM _2.5水平，并在旁观者中引起一些刺激症状。