Presence of the Carcinogen N′-Nitrosonornicotine in Saliva of E-cigarette Users Gabriela
Presence of the Carcinogen N′-Nitrosonornicotine in Saliva of E-cigarette Users Gabriela
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DOI：
10.1021/acs.chemrestox.8b00089
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发表时间：
2018-08-01
影响因子：
4.1
通讯作者：
Stepanov, Irina
中科院分区：
文献类型：
--
作者：
Bustamante, Gabriela;Ma, Bin;Stepanov, Irina
电子烟中存在的许多有害成分的含量远低于香烟烟雾中的含量，电子烟使用者尿液生物标志物的分析结果与这些发现一致。然而，了解长期接触电子烟气溶胶对健康的影响可能需要超越这些比较的思考。在这项研究中，我们研究了电子烟使用者体内烟草特有的口腔和食道致癌物N '-亚硝基去甲尼古丁（NNN）的内源性形成。在20名电子烟使用者，20名吸烟者和19名非吸烟者中分析了唾液NNN，去甲尼古丁和尼古丁以及尿液烟草生物标志物，包括总NNN。还分析了研究参与者使用的电子烟中的去甲尼古丁和NNN水平。电子烟使用者唾液中NNN的平均值为14.6（+/- 23.1）pg/mL，范围从不可定量（低于定量限，LOQ）到76.0 pg/mL。在吸烟者中，唾液NNN的范围从低于LOQ到739 pg/mL，80%的吸烟者的唾液NNN在电子烟使用者中发现的水平范围内。与之前的报告一致，20名电子烟使用者中只有5名存在非常低水平的尿液总NNN（范围为0.001至0.01 pmol/mL尿液）。在电子烟液体中只发现了痕量的NNN。总之，我们的研究结果表明，NNN是在电子烟使用者中内源性形成的。虽然电子烟使用者对NNN的总体暴露明显低于吸烟者，但NNN已知的致癌潜力值得进一步研究其内源性形成的潜在后果。唾液NNN，而不是尿液总NNN，仅占NNN剂量的1-3%，应用于监测电子烟使用者对这种致癌物的暴露。
Many harmful constituents are present in e-cigarettes at much lower levels than in cigarette smoke, and the results of analysis of urinary biomarkers in e-cigarette users are consistent with these findings. However, understanding the health effects of chronic exposures to e-cigarette aerosols may require thinking beyond these comparisons. In this study, we investigated the endogenous formation of the tobacco-specific oral and esophageal carcinogen N'-nitrosonornicotine (NNN) in e-cigarette users. Salivary NNN, nornicotine, and nicotine as well as urinary tobacco biomarkers, including total NNN, were analyzed in 20 e-cigarette users, 20 smokers, and 19 nonsmokers. Nornicotine and NNN levels in e-cigarettes used by the study participants were also analyzed. The mean of NNN in saliva of e-cigarette users was 14.6 (+/- 23.1) pg/mL, ranging from nonquantifiable (below the limit of quantitation, LOQ) to 76.0 pg/mL. In smokers, salivary NNN ranged from below LOQ to 739 pg/mL, with 80% of smokers having salivary NNN in the range of levels found in e-cigarette users. Consistent with a previous report, very low levels of urinary total NNN were present in only 5 out of 20 e-cigarette users (ranging from 0.001 to 0.01 pmol/mL urine). Only trace levels of NNN were found in e-cigarette liquids. Together, our findings demonstrate that NNN is formed endogenously in e-cigarette users. While the overall exposure to NNN in e-cigarette users is dramatically lower than in smokers, the known carcinogenic potency of NNN warrants further investigations into the potential consequences of its endogenous formation. Salivary NNN, rather than urinary total NNN, which accounts for only 1-3% of the NNN dose, should be used to monitor e-cigarette users' exposure to this carcinogen.