Herbert Gilbert is often credited as the creator of the first device that resembled the modern electronic cigarette (e-cigarette), obtaining a patent for it in 1965.1,2 There were many patents filed in the 1990s and early 2000s for nicotine-inhaler devices; however, it wasn't until 2003 that the first commercially successful electronic device was developed by man named Hon Lik (from Beijing, China).1,2 In 2006, electronic cigarettes were introduced in Europe and the United States.
Initially, e-cigarettes were marketed as a less dangerous option than conventional cigarettes; however, the World Health Organization stated in a press release in 2008 that electronic cigarettes were not legitimate smoking-cessation aids or nicotine-replacement therapy given the lack of scientific evidence.3 In 2009, President Barack Obama signed the Family Smoking Prevention and Tobacco Control Act, which allowed the US Food and Drug Administration (FDA) to regulate the tobacco industry.4 However, the FDA did not have authority over e-cigarettes until 2016, when a new tobacco rule expanded the FDA's authority to all tobacco products.5
Since the introduction of e-cigarettes to the US in 2006, there have been rapid changes in the design, delivery, and technology in the devices as well as the e-cigarette liquid solution. Initially, products resembled regular cigarettes that allowed for very little customization. The second-generation devices were commonly known as “vape pens” (given their similarity to a pen) and included clear reservoirs for the electronic cigarette liquid (e-liquid). The third generation of e-cigarettes were larger with a tank system known as “mods” because of the modifications that could be made to the wattage and voltage. Fourth-generation e-cigarettes had additional technology such as temperature control, which could make the vaping experience even more pleasurable. It also saw a departure in design from previous generations, with some popular ones resembling universal serial bus (USB) memory sticks or battery packs.6,7 Many names have been given to e-cigarettes, including “e-cigs,” “e-hookahs,” “mods,” “vapes,” “tank systems,” “electronic nicotine delivery systems,” or just the name of the pods themselves.
The basic principle of e-cigarette delivery is that a user inhales a vapor that is aerosolized when a liquid becomes heated. The typical components of e-cigarettes include a mouth piece, a sensor or user-activated button to activate the heating coil, a battery, an atomizer or heating element, and storage for the e-liquid.2,8 Variations within these design elements can affect the nicotine dose that is delivered to the user.
The e-liquid or e-juice is primarily composed of either propylene glycol (PG) or vegetable glycerin (VG), nicotine, and flavorings.2,7 Although both PG and VG are humectants and generally considered safe for ingestion, there are few human studies regarding long-term effects associated with inhalation. Most e-liquids contain nicotine, typically ranging from 0 to 24 mg/mL, although the e-cigarette brand JUUL advertises nicotine levels as high as 59 mg/mL, which is as much nicotine as there is in an entire pack of cigarettes.9 The pH of the liquid can also affect nicotine delivery. At a higher pH, more nicotine is present in the gas phase, which results in more absorption in the oral cavity and upper respiratory tract, leading to more irritation and unpleasant taste; however, at lower pH, more nicotine is present in the liquid phase, which leads to less irritation and unpleasant taste with increased lung deposition of the aerosol and increased nicotine absorption in the lungs.10 The last component of e-liquid are flavorings, including options like sweets and fruits, which have universal appeal to both adults and youth.6,7
Many reasons are cited for e-cigarette use in adolescents, with the most common reasons being use by a friend or family member, availability of appealing flavors, and belief that e-cigarettes are less harmful than other tobacco products such as cigarettes.11 According to the 2018 National Youth Tobacco Survey, approximately 27% of high school students and 7% of middle school students report any tobacco use within the past 30 days.12 The most commonly used tobacco product was e-cigarettes, with 20.8% (3.05 million) of high school students and 4.9% (570,000) of middle school students reporting use.12 This number increased by about 80% in high school students and about 50% in middle school students from 2017 to 2018.12 Similar findings were noted in the Youth Risk Behavior Surveillance study,13 which sampled a little less than 15,000 high school students and reported that 42.2% of survey participants had used an electronic vapor product and 13.6% of students purchased the product themselves in a store.13 Paralleling the increase in e-cigarette use was the increased sales of JUUL, which currently has a 72.1% share of the US e-cigarette market.6,12
In addition to overall increase in e-cigarette use by US youths, data from 2017 to 2018 indicate that current high school users report a 38.5% increase in the frequency of e-cigarette use and a 22.8% increase in prevalence of using two or more tobacco products.12 Dual users (both e-cigarettes and conventional cigarettes) tend to have lower social-cognitive protective risk factors (ie, parental support or academic involvement), higher social cognitive risk factors (ie, behavioral dysregulation), higher problem behavior risk factors (ie, parent-adolescent conflict, rebelliousness), and higher collateral substance use.14 Some concerns raised by this data and the rapid increase in e-cigarette use are whether e-cigarettes may be enticing youth who otherwise would have remained tobacco-free.15
The Centers for Disease Control and Prevention does not recommend use of e-cigarettes in youth, young adults, and people who do not smoke given the serious risks associated with vaping. Recent reports of a national outbreak of e-cigarette/vaping product use-associated lung injury (EVALI) in the US were particularly concerning given that there were more than 2,800 hospitalized cases with 68 confirmed deaths. Of those reported cases, 15% of patients were younger than age 18 years and 37% were between the ages of 18 and 24 years.16 The cases were strongly linked to a vitamin E acetate, an additive commonly found in vaping products containing tetrahydrocannabinol.16
Although e-cigarettes could be an alternative option for current smokers seeking to quit, a recent meta-analysis indicated that current e-cigarette users have demonstrated significantly less quitting among those who smoke.15,17 Additionally, there are no data on e-cigarettes for smoking cessation in youth.15 Advocates for e-cigarettes cite that users are not exposed to the toxic smoke components of conventional cigarettes; however, it is also important to consider second-hand vaping, which is the emissions of e-cigarettes by users to non-using bystanders, as well as thirdhand aerosol, which includes the nicotine and toxicants present in the environment (mainly on surfaces) after e-cigarette use. Indoor levels of nicotine, fine and ultrafine particulates, and volatile inorganic compounds increase after a vaping session.6,15 For areas in which multiple users are present, concentrations can reach levels found in venues where conventional smoking is permitted.6,15
As a result of the considerable product variability that exists in terms of size, device usage time, nicotine concentration, and e-liquid formulations, the public health impact of these devices can be difficult to assess. Concerns have been raised that e-cigarettes may increase airway resistance, decrease airway conductance, induce endothelial cell dysfunction, impair cilia function, promote oxidative stress, and cause DNA damage and mutagenesis.6,15,18 Furthermore, adolescents with asthma are particularly susceptible to increased cough, wheeze, and asthma exacerbations with e-cigarette use.18
With the modifications that are currently available for e-cigarette devices, users often may vape for longer than they typically would smoke, thus increasing nicotine exposure. As a result, some youth may present with nicotine sickness, which can include abdominal pain, nausea or vomiting, tremors, breathing difficulties, cardiac arrest, or respiratory failure.15 Nicotine poisoning has also seen a rise since 2011, with more than 5,200 cases of e-cigarette and liquid nicotine exposures reported to Poison Control centers in 2019 alone.19 Exposure to e-liquids, either from drinking or eye or skin contact, can present with vomiting, lactic acidosis, seizures, anoxic brain injury, and death.18 Burns and projectile injuries can also result from e-cigarette devices that can explode secondary to the battery component.18
E-cigarettes' impact on an adolescent's developing brain is also understudied, but literature supports that it may increase vulnerability to nicotine addiction.6 Furthermore, long-term consequences may include effects on cognitive function, behavioral concerns, and psychiatric disorders similar to conventional smoking.15 Lastly, there is a real concern that on the population level smoking behavior becomes normalized, leading to greater risk of subsequent initiation of cigarette smoking18,20 and serving as a gateway for alcohol and use of illicit drugs.8,21
State and local governments have been instrumental in enacting laws for e-cigarette prevention. Examples include requiring licenses for retail and online sale of e-cigarettes, prohibiting sale to minors, regulations on the product packaging, and selective taxation.2 In states in which legislation requiring purchasers to be age 21 years or older has not been adopted, advocacy for these laws, which raise the minimum age for purchase of tobacco from age 18 years to age 21 years, may help with limiting the ability of high school students to purchase e-cigarettes.2,6,15 Other policies include limiting the nicotine available in e-cigarette liquids and eliminating flavors that are appealing to youth.
School-based anti-tobacco interventions have significantly reduced tobacco initiation and may also prove beneficial. Some school districts have implemented changes to address the growing pandemic, including removing bathroom doors, installing sensor alarms to detect e-cigarette vapor, and banning USB devices given their resemblance to vaping products on the market.15 The most successful school-based interventions tend to also address social competence (eg, decision-making) and social influence (eg, peer pressure).15
The education of students, parents, health care practitioners, and the general public continues to be an important component in combating e-cigarette use. Strong anti-tobacco messages have been effective in the past with conventional cigarettes and could be expanded to include the dangers of vaping.15 Parental education is also important, as most parents are unable to successfully identify these devices.15 Similarly, more than 80% of physicians knew little to nothing about vaping products, and only one-quarter had been informed through professional sources.15 The more knowledge that is shed on this topic, the better informed all will be in the prevention, identification, and treatment of e-cigarette use.
Only 14% of pediatric providers are routinely screening adolescents regarding e-cigarette use.15 This presents a great opportunity for pediatricians to talk to their patients about vaping and educate them about potential harms or direct them to resources to help with tobacco cessation. For those interested in public health or clinical research, there is much to be understood about the short-term and long-term harms that vaping poses on adolescents as well as the effectiveness of any interventions that are used.
E-cigarettes are the most commonly used tobacco product for adolescents, with rates continuing to rise year after year. The negative health impact on youth and young adults has been demonstrated most recently with the outbreak of EVALI; however, the long-term affects are still largely unknown. As a clinician, one immediate intervention is the incorporation of the topic of vaping during conversations with adolescents. On a broader scale, policymakers, parents, schools, researchers, and health care providers must employ a multipronged approach to address this growing concern.
- Consumer Advocates for Smoke-Free Alternatives Association. A historical timeline of electronic cigarettes. Accessed August 22, 2020. http://www.casaa.org/historical-timeline-of-electronic-cigarettes/
- Bhalerao A, Sivandzade F, Archie SR, Cucullo L. Public health policies on e-cigarettes. Curr Cardiol Rep. 2019;21(10):111. doi:10.1007/s11886-019-1204-y [CrossRef] PMID:31463564
- World Health Organization. Marketers of electronic cigarettes should halt unproved therapy claims. Accessed August 22, 2020. https://www.who.int/mediacentre/news/releases/2008/pr34/en/
- US Food and Administration.Drug Family Smoking Prevention and Tobacco Control Act–an overview. Accessed August 22, 2020. https://www.fda.gov/tobacco-products/rules-regulations-and-guidance/family-smoking-prevention-and-tobacco-control-act-overview
- US Food and Administration.Drug The facts on the FDA's new tobacco rule. Accessed August 22, 2020. https://www.fda.gov/consumers/consumer-updates/facts-fdas-new-tobacco-rule
- Walley SC, Wilson KM, Winickoff JP, Groner J. A public health crisis: electronic cigarettes, vape, and JUUL. Pediatrics. 2019;143(6):e20182741. doi:10.1542/peds.2018-2741 [CrossRef] PMID:31122947
- Consumer Advocates for Smoke-Free Alternatives Association. E-cigarettes: the basics. Accessed August 14, 2020. http://www.casaa.org/electronic-cigarettes/
- Bhatnagar A, Whitsel LP, Ribisl KM, et al. American Heart Association Advocacy Coordinating CommitteeCouncil on Cardiovascular and Stroke Nursing, Council on Clinical CardiologyCouncil on Quality of Care and Outcomes Research. Electronic cigarettes: a policy statement from the American Heart Association. Circulation. 2014;130(16):1418–1436. doi:10.1161/CIR.0000000000000107 [CrossRef] PMID:25156991
- JUUL. Discover more about JUUL pods & flavors. Accessed August 22, 2020. https://www.juul.com/resources/What-is-JUUL-Vape-Liquid-All-JUUL-Pod-Flavors
- Voos N, Goniewicz ML, Eissenberg T. What is the nicotine delivery profile of electronic cigarettes?Expert Opin Drug Deliv. 2019;16(11):1193–1203. doi:10.1080/17425247.2019.1665647 [CrossRef] PMID:31495244
- Tsai J, Walton K, Coleman BN, et al. Reasons for electronic cigarette use among middle and high school students - National Youth Tobacco Survey, United States, 2016. MMWR Morb Mortal Wkly Rep. 2018;67(6):196–200. doi:10.15585/mmwr.mm6706a5 [CrossRef] PMID:29447148
- Gentzke AS, Creamer M, Cullen KA, et al. Vital signs: tobacco product use among middle and high school students - United States, 2011-2018. MMWR Morb Mortal Wkly Rep. 2019;68(6):157–164. doi:10.15585/mmwr.mm6806e1 [CrossRef] PMID:30763302
- Kann L, McManus T, Harris WA, et al. Youth risk behavior surveillance - United States, 2017. MMWR Surveill Summ. 2018;67(8):1–114. doi:10.15585/mmwr.ss6708a1 [CrossRef] PMID:29902162
- Wills TA, Knight R, Williams RJ, Pagano I, Sargent JD. Risk factors for exclusive e-cigarette use and dual e-cigarette use and tobacco use in adolescents. Pediatrics. 2015;135(1):e43–e51. doi:10.1542/peds.2014-0760 [CrossRef] PMID:25511118
- Singh S, Windle SB, Filion KB, et al. E-cigarettes and youth: patterns of use, potential harms, and recommendations. Prev Med. 2020;133:106009. doi:10.1016/j.ypmed.2020.106009 [CrossRef] PMID:32027913
- US Centers for Disease Control and Prevention. Outbreak of lung injury associated with the use of e-cigarette, or vaping, products. Office on Smoking and Health, National Center for Chronic Disease Prevention and Health Promotion. Accessed August 22, 2020. https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.html#map-cases
- Kalkhoran S, Glantz SA. E-cigarettes and smoking cessation in real-world and clinical settings: a systematic review and meta-analysis. Lancet Respir Med. 2016;4(2):116–128. doi:10.1016/S2213-2600(15)00521-4 [CrossRef] PMID:26776875
- National Academies of Sciences, Engineering, and Medicine. Public health consequences of e-cigarettes. The National Academies Press. https://www.nap.edu/catalog/24952/public-health-consequences-of-e-cigarettes
- American Association of Poison Control Centers. E-Cigarettes and liquid nicotine. Accessed August 22, 2020. https://aapcc.org/track/ecigarettes-liquid-nicotine
- Soneji S, Barrington-Trimis JL, Wills TA, et al. Association between initial use of e-cigarettes and subsequent cigarette smoking among adolescents and young adults: a systematic review and meta-analysis. JAMA Pediatr. 2017;171(8):788–797. doi:10.1001/jamapediatrics.2017.1488 [CrossRef] PMID:28654986
- Mehra VM, Keethakumar A, Bohr YM, Abdullah P, Tamim H. The association between alcohol, marijuana, illegal drug use and current use of E-cigarette among youth and young adults in Canada: results from Canadian Tobacco, Alcohol and Drugs Survey 2017. BMC Public Health. 2019;19(1):1208. doi:10.1186/s12889-019-7546-y [CrossRef] PMID:31477067