Gurpreet Singh Guliani, M.D., Steven Lippmann, M.D.

Electronic cigarettes entered the US market in 2007 (1). They quickly gained popularity with e-cigarette use among an estimated 60,000 students in 2011, rising to about 570,000 by 2018 (2). E-cigarette devices have evolved with the latest ones called “pod mods”. They utilize a heating element at a liquid containing nicotine, propylene glycol, flavors, and other chemicals in an oil mixture to generate an aerosol that is inhaled. This occurs without tobacco combustion. It yields a cloud of toxic products that is not water vapor, as the name “vaping” falsely implies.

There is debate about the safety, benefits, and/or risks of e-cigarettes. They are said to be a health benefit by diverting people from using tobacco products. One randomized controlled trail revealed that three months of nicotine containing e-cigarette “vaping” resulted in some smoking abstinence at six months as compared to applying nicotine patches or using nicotine-free e-cigarettes, but differences were insignificant (3). This suggests that e-cigarettes might be a harm-reduction strategy. Other research, however, documents prominent dual, co-usage of e-cigarettes along with conventional smoking, without lowering tobacco consumption and thus provides no harm reduction (4). Although e-cigarettes were first advertised to be a safer than smoking tobacco, there is a general consensus about considerable dangers and addiction to the contrary.  Also, new generations of the electronic atomizers deliver higher levels of nicotine, toxic contents, and sometimes other substances added, like cannabis, methamphetamine, and/or fentanyl (5). Safety for e-cigarettes is not substantiated.

Some recent e-cigarette brands are equivalent in size to a thumb drive and is easily concealed and misused in public spaces. They can heat a nicotine solution which is highly concentrated; it provides nicotine-rich aerosol levels equivalent to 20 combustible cigarettes (5). Tasty flavorings are added that are attractive and reduce irritation and/or smell. Other than sustained addiction, there is little proven correlation between vaping and side effects; yet but several investigations report e-vaping-associated lung injury (EVALI). First reported in August 2019, its frequency has dramatically increased (6). E-vaping associated lung injury includes a common pathophysiological pathway of airway inflammation, edema with epithelial sloughing, hypoxemia, and alveolar inflammation. Vitamin E acetate in bronchoalveolar lavage fluid samples from patients with EVALI evidences that vitamin E acetate from vaping is toxic to respiratory epithelium (6). Heating vitamin E acetate creates unsaturated ketones, a lung irritant, called ketenes (7). E-cigarettes aerosols decrease functioning of respiratory cilia, and that may predisposes people to respiratory infections, including COVID-19 (8). Oxidants present in e-vapor liquid might induce cardiac pathology (9). Other noxious pulmonary irritants are also sometimes present. E-cigarettes avoid tobacco smoke risks, but introduce their own new alternate dangers.

Time, observation, and research should reveal more conclusions about the health effects, risks, and/or safety of e-cigarettes. In the meantime, physicians must help smokers to quit smoking. Abstinence is hard to sustain, but there are ways to encourage abstinence, for example, by tapered nicotine replacement therapies available by prescription or over the counter. Behavioral methods, will-power, and social support methods are also present to help people stop using all sources of nicotine and tobacco products. E-cigarette usage is not an accepted harm-reduction technique.

References

1. Noel JK, Rees VW, Connolly GN. Electronic cigarettes: a new ‘tobacco’ industry? Tob Control. 2011;20(1):81.
2. Cullen KA, Ambrose BK, Gentzke AS, et.al. Notes from the Field: Use of Electronic Cigarettes and Any Tobacco Product Among Middle and High School Students – United States, 2011-2018. MMWR.2018;67(45):1276–1277.
3. Bullen C, Howe C, Laugesen M, et.al. Electronic cigarettes for smoking cessation: a randomized controlled trial. Lancet.2013;382(9905):1629-1637.
4. Dutra LM, Glantz SA. Electronic Cigarettes and Conventional Cigarette Use Among US Adolescents: A Cross-sectional Study. JAMA Pediatr.2014;168(7):610–617.
5. Barrington JL, Leventhal AM. Adolescents’ Use of “Pod Mod” E-Cigarettes- Urgent Concerns. N Engl J Med. 2018;379(12):1099-1102.
6. Blount BC, Karwowski MP, Shields PG, et.al. Lung Injury Response Laboratory Working Group: Vitamin E Acetate in Bronchoalveolar-Lavage Fluid Associated with EVALI. N Engl J Med. 2020;382(8):697-705.
7. Dan Wu, Donal F. Potential for release of pulmonary toxic ketene from vaping pyrolysis of vitamin E acetate. O’Shea Proceedings of the National Academy of Sciences. 2020;117(12):6349-6355.
8. Park HR, O’Sullivan M, Vallarino J, et.al. Transcriptomic response of primary human airway epithelial cells to flavoring chemicals in electronic cigarettes. Sci Rep. 2019;9(1400):1-10.
9. Amirahmadi, R, Childress, J, Patel, S, et.al. Electric cigarette-related lung injury and cardiovascular insult. BMJ Case Reports.2021;14: e238352.Accessed on July 18,2021.