Department of Behavioural Science and Health, University College London, London, United Kingdom.
SPECTRUM Consortium, London, United Kingdom.
JAMA Netw Open. 2024 Jul 1;7(7):e2421246. doi: 10.1001/jamanetworkopen.2024.21246.
With the prevalence of e-cigarette use (vaping) increasing worldwide, there are concerns about children's exposure to secondhand vapor.
To compare nicotine absorption among children who are (1) exposed to secondhand tobacco smoke only or (2) exposed to secondhand vapor only with (3) those exposed to neither.
DESIGN, SETTING, AND PARTICIPANTS: The US Continuous National Health and Nutrition Examination Survey (NHANES) is a repeat cross-sectional survey. Participants are interviewed in their homes and, several days after, visit a mobile examination center to provide biological specimens. This study uses data from a nationally representative sample of US households from 2017 to 2020. Participants were children aged 3 to 11 years with serum cotinine levels incompatible with current firsthand nicotine use (ie, <15 μg/L). The final analysis was conducted on January 9, 2024.
Reported exposure to secondhand smoke or vapor indoors in the past 7 days (only secondhand smoke, only secondhand vapor, or neither). Covariates included age, sex, ethnicity, family income, body weight, and height.
The primary outcome was serum cotinine concentration, an objective biomarker of nicotine absorption. Geometric mean cotinine levels and 95% CIs were calculated using log-normal tobit regression, accounting for the complex survey design and weights.
The mean (SD) age of the 1777 children surveyed was 7.4 (2.6) years, 882 (49.6%) were female, and 531 (29.9%) had family incomes below the poverty level. Nicotine absorption, as indexed by serum cotinine level, was highest among children only exposed to secondhand smoke (0.494 μg/L μg/L; 95% CI, 0.386-0.633 μg/L), followed by those exposed only to secondhand vapor (0.081 μg/L; 95% CI, 0.048-0.137 μg/L), equating to 83.6% (95% CI, 71.5%-90.5%; P < .001) lower nicotine absorption. Among children with no reported secondhand exposure, the geometric mean cotinine level was 0.016 μg/L (95% CI, 0.013-0.021 μg/L), or 96.7% (95% CI, 95.6%-97.6%; P < .001) lower than for those with exposure to secondhand smoke. Results were similar after covariate adjustment.
In this cross-sectional study of US children, nicotine absorption was much lower in children who were exposed to secondhand vapor vs secondhand smoke, but higher than in those exposed to neither. These findings suggest that switching from smoking to vaping indoors may substantially reduce, but not eliminate, children's secondhand exposure to nicotine and other noxious substances.
随着全球电子烟使用（蒸气）的流行，人们对儿童接触二手蒸气的问题感到担忧。
比较（1）仅接触二手烟草烟雾或（2）仅接触二手蒸气或（3）两者均不接触的儿童的尼古丁吸收情况。
设计、地点和参与者：美国连续全国健康和营养调查（NHANES）是一项重复的横断面调查。参与者在家中接受访谈，几天后前往移动体检中心提供生物样本。本研究使用了 2017 年至 2020 年来自美国代表性家庭的全国性样本数据。参与者为年龄在 3 至 11 岁之间、血清可替宁水平与当前首次尼古丁使用不一致（即，<15μg/L）的儿童。最终分析于 2024 年 1 月 9 日进行。
报告过去 7 天内在室内接触二手烟或蒸气（仅二手烟、仅二手蒸气或两者均不接触）。协变量包括年龄、性别、种族、家庭收入、体重和身高。
主要结果是血清可替宁浓度，这是尼古丁吸收的客观生物标志物。使用对数正态 Tobit 回归计算几何均数可替宁水平和 95%置信区间，同时考虑到复杂的调查设计和权重。
接受调查的 1777 名儿童的平均（SD）年龄为 7.4（2.6）岁，882 名（49.6%）为女性，531 名（29.9%）家庭收入低于贫困线。以血清可替宁水平为指标的尼古丁吸收，仅接触二手烟的儿童最高（0.494μg/Lμg/L；95%CI，0.386-0.633μg/L），其次是仅接触二手蒸气的儿童（0.081μg/L；95%CI，0.048-0.137μg/L），这相当于 83.6%（95%CI，71.5%-90.5%；P<.001）的尼古丁吸收降低。在没有报告二手暴露的儿童中，几何平均可替宁水平为 0.016μg/L（95%CI，0.013-0.021μg/L），或比接触二手烟的儿童低 96.7%（95%CI，95.6%-97.6%；P<.001）。在调整协变量后，结果相似。
在这项对美国儿童的横断面研究中，与接触二手烟相比，接触二手蒸气的儿童尼古丁吸收明显较低，但高于两者均不接触的儿童。这些发现表明，室内吸烟改为蒸气可能会大大减少，但不能消除儿童接触二手尼古丁和其他有害物质。
