Secondhand E-Cigarette and Tobacco Smoke Exposure and Stages of E-Cigarette Use in US 6th-12th Graders

Studies examining the association of secondhand exposures with e-cigarette use behaviors have been limited by indirect or incomplete measures of exposure. This study reports the prevalence of secondhand e-cigarette and tobacco smoke exposure among US youth and examines how robust measures of secondhand exposure correlate with e-cigarette susceptibility, ever use, daily use, and quit attempts.

A cross-sectional analysis of 21 946 US 6th-12th graders from the 2023 National Youth Tobacco Survey was conducted. Participants' past 30-day secondhand exposure status was classified as: no secondhand exposure, secondhand e-cigarette only, secondhand tobacco smoke only, or dual secondhand exposure. Multivariate, weighted logistic regression evaluated secondhand exposure status as a predictor of four binary e-cigarette use outcomes in separate models: susceptibility, ever use, daily use, and past 12-month serious quit attempt.

The estimated prevalence of past 30-day secondhand e-cigarette or tobacco smoke exposure was 64.2% (18.18 million). Secondhand exposure to e-cigarettes (adjusted odds ratio [AOR] 2.14 95% CI [1.54-2.98]), tobacco smoke (AOR 1.62 [1.32-2.00]), and dual exposure (AOR 2.44 [2.10-2.84]) were each associated with greater e-cigarette susceptibility. Secondhand e-cigarette (AOR: 2.45 [1.69-3.56]) and dual exposure (AOR: 1.55 [1.23-1.94]), but not secondhand tobacco smoke exposure, were positively associated with e-cigarette ever use. There were no significant associations between secondhand exposure and daily e-cigarette use or serious quit attempts.

Secondhand e-cigarette and tobacco smoke exposure remains highly prevalent among US 6th-12th graders and is strongly associated with early stages of e-cigarette use, but not later stages. Minimizing youth secondhand exposure could have important public health benefits.

This study uses the latest data from the 2023 National Youth Tobacco Survey to highlight how the prevalence of secondhand e-cigarette and tobacco exposure among US 6-12 graders remains quite high (64.2%, 18.18 million) despite decreases in youth tobacco and e-cigarette use since 2019. Furthermore, unlike prior studies limited to examining a single stage of e-cigarette use, this study examines how robust measures of secondhand exposure correlate with outcomes spanning the stages of e-cigarette use: susceptibility, ever use, daily use, and quit attempts. Ultimately, it reinforces secondhand exposure among US youth as an important and timely public health challenge.