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

Abstract

Since e-cigarettes appeared in the mid-2000s, some practitioners, researchers, and policy makers have embraced them as a safer alternative to conventional cigarettes and an effective way to stop smoking. While e-cigarettes deliver lower levels of carcinogens than do conventional cigarettes, they still expose users to high levels of ultrafine particles and other toxins that may substantially increase cardiovascular and noncancer lung disease risks, which account for more than half of all smoking-caused deaths, at rates similar to conventional cigarettes. Moreover, rather than stimulating smokers to switch from conventional cigarettes to less dangerous e-cigarettes or quitting altogether, e-cigarettes are reducing smoking cessation rates and expanding the nicotine market by attracting youth.

Keywords: cancer; cardiovascular disease; lung disease; smoking cessation; smoking initiation.

Figure 1

The advent of e-cigarettes did not affect declining trends in conventional cigarette smoking. After e-cigarettes became available, dual use of cigarettes and e-cigarettes increased, and some youth started using e-cigarettes alone; however, these changes did not affect the declining trend in cigarette use. This pattern was observed in both ever (≥1 puff lifetime; panel a) and current (use in past 30 days; panel b) cigarette use in the National Youth Tobacco Survey (NYTS), including dual use with e-cigarettes (cigarettes only, light brown; dual use, dark brown). E-cigarette-only users (orange) are at low risk of having initiated tobacco products with cigarettes (37). E-cigarette use was assessed starting in 2011. Adapted with permission from Pediatrics 2017 Volume 139, Issue 2, pii: e20162450. doi: 10.1542/peds.2016–2450, Copyright © 2017 by the American Academy of Pediatrics.

Figure 2

Ever e-cigarette use among never smokers at baseline quadruples the odds of being a smoker at follow-up. Meta-analysis is by the authors following Soneji et al. (119). Citations for studies: , , , , , , , , . Note: Weights are from random effects meta-analysis. Abbreviations: CI, confidence interval; OR, odds ratio.

Figure 3

Smokers who use e-cigarettes are significantly less likely to have stopped smoking than smokers who do not use e-cigarettes, with the odds of quitting smoking depressed by 27%. Citations for studies: , , , , , , , , , , , , , , , , , , , , , , . Note: Weights are from random effects analysis. Abbreviations: CI, confidence interval; OR, odds ratio.

Figure 4

Between 1965 and 2015, active and passive smoking killed 21 million people. Although most discussion of smoking and disease focuses on cancer, cardiovascular disease and metabolic and noncancer pulmonary disease kill most smokers (134).

Figure 5

Particle number distribution from (a) mainstream aerosol in high and low nicotine content e-liquids and from (b) conventional cigarette as a function particle size (diameter, D). Adapted from Fuoco et al. (45) with permission from the publisher. Copyright © 2013 Elsevier Ltd.