History of electronic cigarettes and their growing popularity

The origin of e-cigarettes dates back to 1965 when Herbert Gilbert patented the first “smokeless nontobacco cigarette” in the United States (Figure 1) (5). This product was developed as an alternative to tobacco cigarettes, as evidence emerged in the 1960s linking tobacco smoking to lung cancer (5). Gilbert’s battery-powered device delivered heated flavor elements like rum, mint, and cinnamon without combustion or the use of tobacco and nicotine; it quickly became popular but never emerged in commercial markets. Next, in 1986, the “Favor cigarette” emerged as another noncombustible device advertised as an alternative to nicotine containing products but was also unsuccessful (5). In 2003, Chinese pharmacist Hon Lik received support from investors for mass production of his electronic atomizing cigarette in the Chinese market under the company name Ruyan (5). This device was marketed as a smoking cessation tool and alternative to tobacco cigarettes. Widespread advertising and internet marketing contributed to the rapid entrance of this product into U.S. markets in 2006 (5).

Historical timeline of the introduction of e-cigarettes and subsequent notable events.

E-cigarettes create an inhaled aerosol or “vapor” by rapidly heating a customizable liquid, rather than by combustion as in conventional tobacco cigarettes. Their popularity has continued to increase over the past decade. E-cigarette use, defined in one study as use within the past 30 days or ever-use in one’s lifetime more than tripled in 2016 compared to 2011 in middle and high school aged students, and more than doubled in young adults aged 18–24 (5). Another study using a database of participating retailers found that the overall sales of e-cigarettes increased from $11.6 million in 2010 to $751.2 million in 2016 (6). The price of both rechargeable and disposable electronic devices has declined over time, as the tobacco industry bought out many brands and grew to control 72.7% of the market in 2016 compared to a complete absence of ownership in 2010 (6).

In addition to decreasing cost and increasing accessibility, another attraction of these devices is customizability (7). The consumer is able to pick from a variety of devices to deliver the e-cigarette liquid known as e-fluid or e-juice and choose the level of nicotine and flavor (Figure 2). Immense popularity has promoted large scale development, including a wide variety of thousands of flavors with more than 460 brands of e-cigarettes available (10). In the U.S. market, JUUL has become the most popular brand of e-cigarettes with disposable pods, now accounting for more than half of the e-cigarette retail market share (11). In a survey of current or ever e-cigarette users in high school, these products were found to be the most popular, which is concerning given the high nicotine content of JUUL e-cigarette fluid compared to other e-cigarette brands (12,13). These often-rechargeable electronic devices with refillable and disposable cartridges continue to become more advanced and generate smaller particles with more effective nicotine delivery (7), thus potentially making them more addictive (Figure 3).

The e-cigarette epidemic. Various forms of e-cigarette products currently available ranging from an elite-appearing cigar to more metallic vaping devices with colorful products to more cig-alike e-cigarettes as shown in both panels above. Image on left obtained from ref (8); image on the right obtained from ref (9). Prepared for World Health Organization Tobacco Free Initiative. December 2013. Accessed Apr 2, 2020. Reprinted with permission from UCSF.

The evolution of electronic cigarettes. (A) Illustration of first, second and third generation electronic cigarettes. While e-cigarettes started out as a cig-alike devices, they have evolved into more user-friendly tools with the customer’s ability to control the resistance of aerosolization process and subsequent effect. (B) The wick and coil components of the atomizers in e-cigarettes harbor various chemicals with known risks of pulmonary toxicity. Permission (14) to reprint granted by The American Physiological Society.

In December 2019, the President signed the Tobacco 21 legislation raising the minimum age for sale of tobacco and e-cigarette products from 18 to 21 years old (15). The increase in regulation came at a time when studies showed increasing levels of adolescent e-cigarette use and advertisements targeting this population (Figure 4). One study found the prevalence of ever use of e-cigarettes to be highest in individuals age 18 to 34, even after stratification by concurrent cigarette smoking status (16). A higher likelihood of ever e-cigarette use was also found in individuals with a lower education level attained, incomes below the poverty level, and with individuals that are separated, widowed, or divorced (16). The increasing popularity of these devices among youth was also exemplified by a 10% increase in amount of 12^th grade youth vaping observed between 2017 and 2018 in the U.S. (17).

Various advertisements for electronic cigarettes and vaping devices portraying them as suitable smoking cessation tools, including writing logos such as “Nobody likes a quitter; so make the switch today” and “Take back your freedom”. From the collection of Stanford Research into the Impact of Tobacco Advertising (tobacco.stanford.edu).

The growing popularity of e-cigarettes may contribute to the social acceptance of traditional cigarette smoking as “e-cig” devices simulate tobacco products and often contain nicotine. One study examining the prevalence of e-cigarette use found that the majority of current e-cigarette users are also concurrent tobacco cigarette users (68.1%) or former smokers (23.7%) (18). Albeit, there is a growing number of never-smokers who are also adopting e-cigarettes in order to “fit-in” (8.2%) (18).