Adolescents' understanding and use of nicotine in e-cigarettes

Nicotine harms adolescent brain development and contributes to addiction. Some adolescents report using nicotine-free e-cigarettes, but the accuracy of their reporting is unclear. We explored adolescents' use of nicotine-free e-cigarettes and understanding of chemicals in e-cigarettes, including nicotine.

Using social media, we recruited 1589 US adolescents (aged 15-17) who reported past 30-day use of e-cigarettes in 2016. We assessed perceptions of the nicotine source in e-liquid and whether e-cigarette aerosol is just "water vapor." We explored differences among adolescents who usually used e-cigarettes with nicotine (n = 473) and without nicotine (n = 452). We used weights to calibrate our sample to the Youth Risk Behavior Survey.

Twenty-nine percent usually used e-cigarettes without nicotine, 28% with nicotine, 39% with "both," and 5% were "not sure." Few participants (17% of non-nicotine users vs. 34% of nicotine users, p < .001) understood the nicotine was derived from tobacco. Youth who thought e-cigarette aerosol was just water vapor were more likely to usually use without nicotine. Older adolescents and current tobacco users were less likely to usually use without nicotine.

The adolescents who reported usually using e-cigarettes without nicotine had poorer knowledge of e-cigarettes. This lack of understanding could contribute to inaccurate reporting of nicotine use. Most youth thought the nicotine in e-cigarettes was artificial, potentially indicating a belief that this nicotine is "safer." The US Food & Drug Administration will require nicotine warnings on e-cigarettes in 2018; a complementary educational campaign could address youths' misperceptions about nicotine and other chemicals in e-cigarette aerosol.