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Youth Vaping

New study suggests two-way association between experimenting with e-cigarettes and experimenting with smoking among young people

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E-Cigarettes: Use, Effects on Smoking, Risks, and Policy Implications

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More evidence that youth e-cig use promotes cigarette smoking

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Trajectories of E-Cigarette and Conventional Cigarette Use Among Youth

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Studying the interactive effects of menthol and nicotine among youth

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Investors Demand Action from Hollywood on Smoking in Youth-Rated Films

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E-cigarette use and asthma in a multiethnic sample of adolescents

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Pulmonary toxicity of e-cigarettes


Electronic cigarettes (e-cigarettes or e-cigs) are designed to heat and aerosolize mixtures of vegetable glycerin, propylene glycol, nicotine, and flavoring additives, thus delivering nicotine by inhalation in the absence of combustion. These devices were originally developed to facilitate smoking cessation and have been available in the United States for over a decade. Since 2010, e-cig use has expanded rapidly, especially among adolescents, despite a paucity of short- and long-term safety data. Patterns of use have shifted to include never smokers and many dual users of e-cigs and combustible tobacco products. Over the last several years, research into the potential toxicities of e-cig aerosols has grown exponentially. In the interim, regulatory policymakers across the world have struggled with how to regulate an increasingly diverse array of suppliers and products, against a backdrop of strong advocacy from users, manufacturers, and tobacco control experts. Herein we provide an updated review of the pulmonary toxicity profile of these devices, summarizing evidence from cell culture, animal models, and human subjects. We highlight the major gaps in our current understanding, emphasize the challenges confronting the scientific and regulatory communities, and identify areas that require more research in this important and rapidly evolving field.

Association Between Initial Use of e-Cigarettes and Subsequent Cigarette Smoking Among Adolescents and Young Adults

A Systematic Review and Meta-analysis.



The public health implications of e-cigarettes depend, in part, on whether e-cigarette use affects the risk of cigarette smoking.


To perform a systematic review and meta-analysis of longitudinal studies that assessed initial use of e-cigarettes and subsequent cigarette smoking.


PubMed, EMBASE, Cochrane Library, Web of Science, the 2016 Society for Research on Nicotine and Tobacco 22nd Annual Meeting abstracts, the 2016 Society of Behavioral Medicine 37th Annual Meeting & Scientific Sessions abstracts, and the 2016 National Institutes of Health Tobacco Regulatory Science Program Conference were searched between February 7 and February 17, 2017. The search included indexed terms and text words to capture concepts associated with e-cigarettes and traditional cigarettes in articles published from database inception to the date of the search.


Longitudinal studies reporting odds ratios for cigarette smoking initiation associated with ever use of e-cigarettes or past 30-day cigarette smoking associated with past 30-day e-cigarette use. Searches yielded 6959 unique studies, of which 9 met inclusion criteria (comprising 17 389 adolescents and young adults).


Study quality and risk of bias were assessed using the Newcastle-Ottawa Scale and the Risk of Bias in Non-randomized Studies of Interventions tool, respectively. Data and estimates were pooled using random-effects meta-analysis.


Among baseline never cigarette smokers, cigarette smoking initiation between baseline and follow-up. Among baseline non-past 30-day cigarette smokers who were past 30-day e-cigarette users, past 30-day cigarette smoking at follow-up.


Among 17 389 adolescents and young adults, the ages ranged between 14 and 30 years at baseline, and 56.0% were female. The pooled probabilities of cigarette smoking initiation were 30.4% for baseline ever e-cigarette users and 7.9% for baseline never e-cigarette users. The pooled probabilities of past 30-day cigarette smoking at follow-up were 21.5% for baseline past 30-day e-cigarette users and 4.6% for baseline non-past 30-day e-cigarette users. Adjusting for known demographic, psychosocial, and behavioral risk factors for cigarette smoking, the pooled odds ratio for subsequent cigarette smoking initiation was 3.62 (95% CI, 2.42-5.41) for ever vs never e-cigarette users, and the pooled odds ratio for past 30-day cigarette smoking at follow-up was 4.28 (95% CI, 2.52-7.27) for past 30-day e-cigarette vs non-past 30-day e-cigarette users at baseline. A moderate level of heterogeneity was observed among studies (I2 = 60.1%).


e-Cigarette use was associated with greater risk for subsequent cigarette smoking initiation and past 30-day cigarette smoking. Strong e-cigarette regulation could potentially curb use among youth and possibly limit the future population-level burden of cigarette smoking.

How e-cigarette ads might sway teens to try tobacco products

When non-smoking teens see ads for e-cigarettes, and are curious about the products advertised, perhaps even identifying with a favorite brand, they might also be more susceptible to taking up cigarettes, a new study finds.

For the study, researchers showed a nationally representative sample of 10,751 U.S. teens advertisements for a wide variety of tobacco products including traditional cigarettes, cigars, chewing tobacco and e-cigarettes. Overall, the teens were more receptive to ads for e-cigarettes than other products and television ads were most likely to prompt brand recall.

“The imagery used by tobacco companies focuses on the aspirations of young people including having fun, being independent, sophisticated, socially accepted, popular, etc.,” said lead study author John Pierce of the University of California, San Diego.

“Those who have an emotive response to these aspirational images are more likely to see use of the product as a way to achieve their aspirations,” Pierce said by email. “It is hypothesized that in adolescents who are committed never smokers, recall of tobacco product advertising will be associated with first movement toward product use within a one-year time frame.”

Big U.S. tobacco companies are all developing e-cigarettes, battery-powered gadgets with a heating element that turns liquid nicotine and flavorings into a cloud of vapor that users inhale.

For the past decade, public health experts have debated whether the devices might help with smoking cessation or at least be a safer alternative to smoking traditional combustible cigarettes, or whether they might lure a new generation into nicotine addiction.

Fewer teens smoke today than a generation ago, but declines in traditional cigarette use have stalled and e-cigarettes have become increasingly popular in recent years. As of 2015, an estimated 16 percent of U.S. high school students used e-cigarettes, compared with about 9 percent for traditional cigarettes, according to the U.S. Centers for Disease Control and Prevention.

While television ads for traditional cigarettes have been illegal in the U.S. for decades, e-cigarette ads are currently allowed on TV, researchers note in Pediatrics.

In the study, Pierce and his colleagues examined how receptive or curious non-smoking teens were about different tobacco products and whether they had a favorite image or advertisement. They also looked at how susceptible the adolescents might be to trying tobacco products based on their ability to recall specific brands they saw in the ads.

The researchers showed each study participant a random selection of five ads each for cigarettes, e-cigarettes smokeless tobacco and cigars based on 959 different promotions that had recently been used to advertise these products.

Overall, 41 percent of the younger teens in the study and half of older adolescents were receptive to at least one tobacco advertisement, the study found.

Across each age group, teens were most receptive to ads for e-cigarettes, followed by traditional cigarettes and smokeless tobacco.

E-cigarette ads shown on television had the highest recall.

Compared to teens in the study who were not at all receptive to the ads, youth who had the highest level of engagement with the promotions were more than six times more likely to be susceptible to trying tobacco products, the study found.

The study isn’t a controlled experiment designed to prove whether or how ads may directly influence tobacco use.

Another limitation is that researchers didn’t have data to show whether or not teens actually used tobacco products after viewing these ads, the authors note.

Even so, the findings suggest that non-cigarette ads for tobacco-related products may be damaging for adolescent health, Rebecca Collins of Rand Corporation in Santa Monica, California, writes in an accompanying editorial.

“This study provides some very provocative data suggesting that the marketing of e-cigarettes, which is not regulated, might be leading to cigarette smoking among teens,” Collins said by email.