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National Center for Chronic Disease Prevention and Health Promotion (US) Office on Smoking and Health. E-Cigarette Use Among Youth and Young Adults: A Report of the Surgeon General [Internet]. Atlanta (GA): Centers for Disease Control and Prevention (US); 2016.

E-Cigarette Use Among Youth and Young Adults: A Report of the Surgeon General [Internet].

Chapter 1 introduction, conclusions, and historical background relative to e-cigarettes.

• Introduction

Although conventional cigarette smoking has declined markedly over the past several decades among youth and young adults in the United States ( U.S. Department of Health and Human Services [USDHHS] 2012 ), there have been substantial increases in the use of emerging tobacco products among these populations in recent years ( Centers for Disease Control and Prevention [CDC] 2015c ). Among these increases has been a dramatic rise in electronic cigarette (e-cigarette) use among youth and young adults. It is crucial that the progress made in reducing cigarette smoking among youth and young adults not be compromised by the initiation and use of e-cigarettes. This Surgeon General’s report focuses on the history, epidemiology, and health effects of e-cigarette use among youth and young adults; the companies involved with marketing and promoting these products; and existing and proposed public health policies regarding the use of these products by youth and young adults.

E-cigarettes include a diverse group of devices that allow users to inhale an aerosol, which typically contains nicotine, flavorings, and other additives. E-cigarettes vary widely in design and appearance, but generally operate in a similar manner and are composed of similar components ( Figure 1.1 ). A key challenge for surveillance of the products and understanding their patterns of use is the diverse and nonstandard nomenclature for the devices ( Alexander et al. 2016 ). These devices are referred to, by the companies themselves, and by consumers, as “e-cigarettes,” “e-cigs,” “cigalikes,” “e-hookahs,” “mods,” “vape pens,” “vapes,” and “tank systems.” In this report, the term “e-cigarette” is used to represent all of the various products in this rapidly diversifying product category. The terms may differ by geographic region or simply by the prevailing preferences among young users. For example, some refer to all cigarette-shaped products as “e-cigarettes” or as “cigalikes,” and some may refer to the pen-style e-cigarettes as “hookah pens” or “vape pens” ( Richtel 2014 ; Lempert et al. 2016 ).

Diversity of e-cigarette products. Source: Photo by Mandie Mills, CDC.

This report focuses on research conducted among youth and young adults because of the implications of e-cigarette use in this population, particularly the potential for future public health problems. Understanding e-cigarette use among young persons is critical because previous research suggests that about 9 in 10 adult smokers first try conventional cigarettes during adolescence ( USDHHS 2012 ). Similarly, youth e-cigarette experimentation and use could also extend into adulthood; however, e-cigarette use in this population has not been examined in previous reports of the Surgeon General. The first Surgeon General’s report on the health consequences of smoking was published in 1964; of the subsequent reports, those published in 1994 and 2012 focused solely on youth and young adults ( USDHHS 1994 , 2012 ). More recently, the 2012 report documented the evidence regarding tobacco use among youth and young adults, concluding that declines in cigarette smoking had slowed and that decreases in the use of smokeless tobacco had stalled. That report also found that the tobacco industry’s advertising and promotional activities are causal to the onset of smoking in youth and young adults and the continuation of such use as adults ( USDHHS 2012 ). However, the 2012 report was prepared before e-cigarettes were as widely promoted and used in the United States as they are now. Therefore, this 2016 report documents the scientific literature on these new products and their marketing, within the context of youth and young adults. This report also looks to the future by examining the potential impact of e-cigarette use among youth and young adults, while also summarizing the research on current use, health consequences, and marketing as it applies to youth and young adults.

Evidence for this report was gathered from studies that included one or more of three age groups. We defined these age groups to be young adolescents (11–13 years of age), adolescents (14–17 years of age), and young adults (18–24 years of age). Some studies refer to the younger groups more generally as youth. Despite important issues related to e-cigarette use in adult populations, clinical and otherwise (e. g ., their potential for use in conventional smoking cessation), that literature will generally not be included in this report unless it also discusses youth and young adults ( Farsalinos and Polosa 2014 ; Franck et al. 2014 ; Grana et al. 2014 ).

Given the recency of the research that pertains to e-cigarettes, compared with the decades of research on cigarette smoking, the “precautionary principle” is used to guide actions to address e-cigarette use among youth and young adults. This principle supports intervention to avoid possible health risks when the potential risks remain uncertain and have been as yet partially undefined ( Bialous and Sarma 2014 ; Saitta et al. 2014 ; Hagopian et al. 2015 ). Still, the report underscores and draws its conclusions from the known health risks of e-cigarette use in this age group.

Organization of the Report

This chapter presents a brief introduction to this report and includes its major conclusions followed by the conclusions of the chapters, the historical background of e-cigarettes, descriptions of the products, a review of the marketing and promotional activities of e-cigarette companies, and the current status of regulations from the U.S. Food and Drug Administration ( FDA ). Chapter 2 (“Patterns of E-Cigarette Use Among U.S. Youth and Young Adults”) describes the epidemiology of e-cigarette use, including current use (i.e., past 30 day); ever use; co-occurrence of using e-cigarettes with other tobacco products, like cigarettes; and psychosocial factors associated with using e-cigarettes, relying on data from the most recent nationally representative studies available at the time this report was prepared. Chapter 3 (“Health Effects of E-Cigarette Use Among U.S. Youth and Young Adults”) documents the evidence related to the health effects of e-cigarette use, including those that are associated with direct aerosol inhalation by users, the indirect health effects of e-cigarette use, other non-aerosol health effects of e-cigarette use, and secondhand exposure to constituents of the aerosol. Chapter 4 (“Activities of the E-Cigarette Companies”) describes e-cigarette companies’ influences on e-cigarette use and considers manufacturing and price; the impact of price on sales and use; the rapid changes in the industry, particularly the e-cigarette companies; and the marketing and promotion of e-cigarettes. Chapter 5 (“E-Cigarette Policy and Practice Implications”) discusses the implications for policy and practice at the national, state, and local levels. The report ends with a Call to Action to stakeholders—including policymakers, public health practitioners and clinicians, researchers, and the public—to work to prevent harms from e-cigarette use and secondhand aerosol exposure among youth and young adults.

Preparation of this Report

This Surgeon General’s report was prepared by the Office on Smoking and Health, National Center for Chronic Disease Prevention and Health Promotion, CDC , which is part of USDHHS . The initial drafts of the chapters were written by 27 experts who were selected for their knowledge of the topics addressed. These contributions are summarized in five chapters that were evaluated by approximately 30 peer reviewers. After peer review, the entire manuscript was sent to more than 20 scientists and other experts, who examined it for its scientific integrity. After each review cycle, the drafts were revised by the report’s scientific editors on the basis of reviewers’ comments. Subsequently, the report was reviewed by various institutes and agencies within USDHHS.

Scientific Basis of the Report

The statements and conclusions throughout this report are documented by the citation of studies published in the scientific literature. Publication lags have prevented an up-to-the-minute inclusion of all recently published articles and data. This overall report primarily cites peer-reviewed journal articles, including reviews that integrate findings from numerous studies and books that were published through December 2015. However, selected studies from 2016 have been added during the review process that provide further support for the conclusions in this report. When a cited study has been accepted for publication, but the publication has not yet occurred because of the delay between acceptance and final publication, the study is referred to as “in press.” This report also refers, on occasion, to unpublished research, such as presentations at a professional meeting, personal communications from a researcher, or information available in various media. These references are employed when acknowledged by the editors and reviewers as being from reliable sources, which add to the emerging literature on a topic.

• Major Conclusions
• E-cigarettes are a rapidly emerging and diversified product class. These devices typically deliver nicotine, flavorings, and other additives to users via an inhaled aerosol. These devices are referred to by a variety of names, including “e-cigs,” “e-hookahs,” “mods,” “vape pens,” “vapes,” and “tank systems.”
• E-cigarette use among youth and young adults has become a public health concern. In 2014, current use of e-cigarettes by young adults 18–24 years of age surpassed that of adults 25 years of age and older.
• E-cigarettes are now the most commonly used tobacco product among youth, surpassing conventional cigarettes in 2014. E-cigarette use is strongly associated with the use of other tobacco products among youth and young adults, including combustible tobacco products.
• The use of products containing nicotine poses dangers to youth, pregnant women, and fetuses. The use of products containing nicotine in any form among youth, including in e-cigarettes, is unsafe.
• E-cigarette aerosol is not harmless. It can contain harmful and potentially harmful constituents, including nicotine. Nicotine exposure during adolescence can cause addiction and can harm the developing adolescent brain.
• E-cigarettes are marketed by promoting flavors and using a wide variety of media channels and approaches that have been used in the past for marketing conventional tobacco products to youth and young adults.
• Action can be taken at the national, state, local, tribal, and territorial levels to address e-cigarette use among youth and young adults. Actions could include incorporating e-cigarettes into smokefree policies, preventing access to e-cigarettes by youth, price and tax policies, retail licensure, regulation of e-cigarette marketing likely to attract youth, and educational initiatives targeting youth and young adults.
• Chapter Conclusions

Chapter 1. Introduction, Conclusions, and Historical Background Relative to E-Cigarettes

• E-cigarettes are devices that typically deliver nicotine, flavorings, and other additives to users via an inhaled aerosol. These devices are referred to by a variety of names, including “e-cigs,” “e-hookahs,” “mods,” “vape pens,” “vapes,” and “tank systems.”
• E-cigarettes represent an evolution in a long history of tobacco products in the United States, including conventional cigarettes.
• In May 2016, the Food and Drug Administration issued the deeming rule, exercising its regulatory authority over e-cigarettes as a tobacco product.

Chapter 2. Patterns of E-Cigarette Use Among U.S. Youth and Young Adults

• Among middle and high school students, both ever and past-30-day e-cigarette use have more than tripled since 2011. Among young adults 18–24 years of age, ever e-cigarette use more than doubled from 2013 to 2014 following a period of relative stability from 2011 to 2013.
• The most recent data available show that the prevalence of past-30-day use of e-cigarettes is similar among high school students (16% in 2015, 13.4% in 2014) and young adults 18–24 years of age (13.6% in 2013–2014) compared to middle school students (5.3% in 2015, 3.9% in 2014) and adults 25 years of age and older (5.7% in 2013–2014).
• Exclusive, past-30-day use of e-cigarettes among 8th-, 10th-, and 12th-grade students (6.8%, 10.4%, and 10.4%, respectively) exceeded exclusive, past-30-day use of conventional cigarettes in 2015 (1.4%, 2.2%, and 5.3%, respectively). In contrast—in 2013–2014 among young adults 18–24 years of age—exclusive, past-30-day use of conventional cigarettes (9.6%) exceeded exclusive, past-30-day use of e-cigarettes (6.1%). For both age groups, dual use of these products is common.
• E-cigarette use is strongly associated with the use of other tobacco products among youth and young adults, particularly the use of combustible tobacco products. For example, in 2015, 58.8% of high school students who were current users of combustible tobacco products were also current users of e-cigarettes.
• Among youth—older students, Hispanics, and Whites are more likely to use e-cigarettes than younger students and Blacks. Among young adults—males, Hispanics, Whites, and those with lower levels of education are more likely to use e-cigarettes than females, Blacks, and those with higher levels of education.
• The most commonly cited reasons for using e-cigarettes among both youth and young adults are curiosity, flavoring/taste, and low perceived harm compared to other tobacco products. The use of e-cigarettes as an aid to quit conventional cigarettes is not reported as a primary reason for use among youth and young adults.
• Flavored e-cigarette use among young adult current users (18–24 years of age) exceeds that of older adult current users (25 years of age and older). Moreover, among youth who have ever tried an e-cigarette, a majority used a flavored product the first time they tried an e-cigarette.
• E-cigarette products can be used as a delivery system for cannabinoids and potentially for other illicit drugs. More specific surveillance measures are needed to assess the use of drugs other than nicotine in e-cigarettes.

Chapter 3. Health Effects of E-Cigarette Use Among U.S. Youth and Young Adults

• Nicotine exposure during adolescence can cause addiction and can harm the developing adolescent brain.
• Nicotine can cross the placenta and has known effects on fetal and postnatal development. Therefore, nicotine delivered by e-cigarettes during pregnancy can result in multiple adverse consequences, including sudden infant death syndrome, and could result in altered corpus callosum, deficits in auditory processing, and obesity.
• E-cigarettes can expose users to several chemicals, including nicotine, carbonyl compounds, and volatile organic compounds, known to have adverse health effects. The health effects and potentially harmful doses of heated and aerosolized constituents of e-cigarette liquids, including solvents, flavorants, and toxicants, are not completely understood.
• E-cigarette aerosol is not harmless “water vapor,” although it generally contains fewer toxicants than combustible tobacco products.
• Ingestion of e-cigarette liquids containing nicotine can cause acute toxicity and possibly death if the contents of refill cartridges or bottles containing nicotine are consumed.

Chapter 4. Activities of the E-Cigarette Companies

• The e-cigarette market has grown and changed rapidly, with notable increases in total sales of e-cigarette products, types of products, consolidation of companies, marketing expenses, and sales channels.
• Prices of e-cigarette products are inversely related to sales volume: as prices have declined, sales have sharply increased.
• E-cigarette products are marketed in a wide variety of channels that have broad reach among youth and young adults, including television, point-of-sale, magazines, promotional activities, radio, and the Internet.
• Themes in e-cigarette marketing, including sexual content and customer satisfaction, are parallel to themes and techniques that have been found to be appealing to youth and young adults in conventional cigarette advertising and promotion.

Chapter 5. E-Cigarette Policy and Practice Implications

• The dynamic nature of the e-cigarette landscape calls for expansion and enhancement of tobacco-related surveillance to include (a) tracking patterns of use in priority populations; (b) monitoring the characteristics of the retail market; (c) examining policies at the national, state, local, tribal, and territorial levels; (d) examining the channels and messaging for marketing e-cigarettes in order to more fully understand the impact future regulations could have; and (e) searching for sentinel health events in youth and young adult e-cigarette users, while longer-term health consequences are tracked.
• Strategic, comprehensive research is critical to identify and characterize the potential health risks from e-cigarette use, particularly among youth and young adults.
• The adoption of public health strategies that are precautionary to protect youth and young adults from adverse effects related to e-cigarettes is justified.
• A broad program of behavioral, communications, and educational research is crucial to assess how youth perceive e-cigarettes and associated marketing messages, and to determine what kinds of tobacco control communication strategies and channels are most effective.
• Health professionals represent an important channel for education about e-cigarettes, particularly for youth and young adults.
• Diverse actions, modeled after evidence-based tobacco control strategies, can be taken at the state, local, tribal, and territorial levels to address e-cigarette use among youth and young adults, including incorporating e-cigarettes into smoke-free policies; preventing the access of youth to e-cigarettes; price and tax policies; retail licensure; regulation of e-cigarette marketing that is likely to attract youth and young adults, to the extent feasible under the law; and educational initiatives targeting youth and young adults. Among others, research focused on policy, economics, and the e-cigarette industry will aid in the development and implementation of evidence-based strategies and best practices.
• Historical Background

Understanding the role of e-cigarettes requires understanding the long history of tobacco use in the United States, including the role of nicotine delivery, the multiple examples of “reduced-harm” products and associated health claims, and the impact of using tobacco products on the public’s health. Since the late nineteenth century, when the “modern” cigarette came into use, scientists and public health officials have linked cigarette smoking to a remarkable number of adverse effects, and it is now recognized as the primary cause of premature death in the United States ( USDHHS 2014 ). Correspondingly, for a century, manufacturers, scientists, entrepreneurs, and public health leaders have promoted or recommended product changes that might remove some of the harmful elements in cigarette smoke. E-cigarettes are among the latest products.

E-cigarettes are designed for users to inhale nicotine, flavorings, and other additives through an aerosol. The claims and marketing strategies employed by the e-cigarette companies, and the efforts made by others to develop scientific and regulatory tools to deal with these new products, both contribute to the current discourse on e-cigarettes. Many lessons for assessing the potential (and future) consequences of these products can be learned from examining the relevant experiences of the past century, especially the introduction of novel products (including e-cigarettes as well as other tobacco and nicotine products) and the claims of reduced exposure to toxins made by the industry and elsewhere.

Early Efforts to Modify Cigarettes

In the 1880s and 1890s, entrepreneurs promoted novel products that allegedly blocked nicotine and other constituents of conventional cigarettes believed to be poisonous. Dr. Scott’s Electric Cigarettes, advertised in Harper’s Weekly, claimed not only to light without matches but also to contain a cotton filter that “strains and eliminates the injurious qualities from the smoke,” including nicotine ( Harper’s Weekly 1887 ). Nicotine delivery was essential to the development of the modern cigarette in the twentieth century; early on, this substance was thought to be addicting and thus vital to retaining customers. In 1913, the Camel brand was a new kind of cigarette that introduced high-nicotine content by using burley tobacco, which was generally too harsh to inhale into the lungs, but was made more inhalable through the addition of casings (e. g ., sugars, licorice) ( Tindall 1992 ; Proctor 2011 ). In 1916, American Tobacco introduced its Lucky Strike blended cigarette, and in 1918 Liggett & Myers ( L &M) reformulated its Chesterfield brand to make it more palatable to users. As the market grew, advertisements for major brands routinely included health-related statements and testimonials from physicians. During the 1930s and 1940s, prominent advertising campaigns included claims like “Not a cough in a carload” (Old Gold) ( Federal Trade Commission [FTC] 1964 , p. LBA-5); “We removed from the tobacco harmful corrosive ACRIDS (pungent irritants) present in cigarettes manufactured in the old-fashioned way” (Lucky Strike) ( FTC 1964 , p. LBA-2); and “Smoking Camels stimulates the natural flow of digestive fluids … increases alkalinity” (Camel) ( FTC 1964 , p. LBA-1a). Thus, early modifications to the cigarette were made so that it was more palatable, had a higher nicotine delivery and uptake, and could be marketed as “safe” ( FTC 1964 ; Calfee 1985 ).

Filters, Tar Reduction, and Light and Low-Tar Cigarettes

The landmark 1964 Surgeon General’s report on smoking and health concluded that cigarette smoking contributed substantially to mortality from certain specific diseases, including lung cancer ( U.S. Department of Health, Education, and Welfare 1964 ). Although the 1964 report considered the topic, it found the evidence insufficient to assess the potential health benefits of cigarette filters. Cigarettes with filters became the norm by the 1960s, and marketing them with an overt message about harm reduction became the standard ( National Cancer Institute [NCI] 1996 ). However, the Surgeon General convened another group of experts on June 1, 1966, to review the evidence on the role played by the tar and nicotine content in health. The group concluded that “[t]he preponderance of scientific evidence strongly suggests that the lower the ‘tar’ and nicotine content of cigarette smoke, the less harmful are the effects” ( Horn 1966 , p. 16,168). Subsequent studies have repeatedly failed to demonstrate health benefits of smoking light and low-tar cigarettes versus full-flavor cigarettes ( Herning et al. 1981 ; Russell et al. 1982 ; Benowitz et al. 1983 , NCI 2001 ).

Over the years, the tobacco industry used multiple methods to reduce the machine-tested yields of tar and nicotine in cigarettes as a way to claim “healthier” cigarettes. Beginning in the 1970s, tobacco companies advertised the tar and nicotine levels for their cigarettes, which encouraged smokers to believe, without substantiation, they could reduce their risk of exposure to these constituents ( Cummings et al. 2002 ; Pollay and Dewhirst 2002 ). In 1996, the FTC issued a statement that it would allow cigarette companies to include statements about tar and nicotine content in their advertising as long as they used a standardized machine-testing method ( Peeler 1996 ).

The Role of Nicotine and Nicotine Delivery

Although the public health community understood early on that nicotine was the primary psycho-active ingredient in cigarette smoke, before the 1980s, little was known about the importance of nicotine in the addiction process beyond what the cigarette manufacturers had learned from their own research. Some scientists warned that due to nicotine addiction, a reduction in nicotine yields, along with decreases in tar, could lead smokers to change their smoking behavior, such as by smoking a greater number of cigarettes to maintain their nicotine intake or changing their behavior in more subtle ways, such as varying the depth of inhalation or smoking more of the cigarette ( Jarvis et al. 2001 ; National Cancer Institute 2001 ; Thun and Burns 2001 ). Not until the 1970s and 1980s, as researchers studying other forms of drug abuse began to apply their research methods to cigarette smoking, did it become apparent that nicotine was similar in its addictive capability to other drugs of abuse, such as heroin and cocaine ( USDHHS 1981 , 1988 ). As described in the 1988 Surgeon General’s report and in subsequent research, symptoms associated with nicotine addiction include craving, withdrawal, and unconscious behaviors to ensure consistent intake of nicotine ( USDHHS 1988 ; al’Absi et al. 2002 ; Hughes 2007 ).

Although the tobacco industry has long understood the importance of nicotine to maintain long-term cigarette smokers through addiction, public health officials did not fully appreciate this in a broad sense until the 1988 Surgeon General’s report, The Health Consequences of Smoking: Nicotine Addiction ( USDHHS 1988 ).

FDA and Nicotine Regulation

In 1988 (and again in 1994), the Coalition on Smoking OR Health and other public-interest organizations petitioned FDA to classify low-tar and nicotine products as drugs and to classify Premier, the short-lived “smokeless cigarette product” from R.J. Reynolds, as an alternative nicotine-delivery system ( Stratton et al. 2001 ). The Coalition on Smoking OR Health cited indirect claims made through advertising and marketing as evidence of R. J. Reynolds’s intent to have the product used for the mitigation or prevention of disease ( Slade and Ballin 1993 ). Meanwhile, FDA launched an investigation into the practices of the tobacco industry, including the manipulation of nicotine delivery. FDA asserted its jurisdiction over cigarettes and smokeless tobacco and issued certain rules governing access to and promotion of these products ( Federal Register 1996 ). On March 21, 2000, the U.S. Supreme Court ruled 5-4 that Congress had not yet given FDA the necessary statutory authority to issue any rules pertaining to tobacco products ( Gottleib 2000 ; FDA v. Brown & Williamson Tobacco Corp. 2000 ). The subsequent debate over control of nicotine products, including their potential impact on youth, ultimately led to the passage of the 2009 Family Smoking Prevention and Tobacco Control Act, which gave FDA authority to regulate tobacco products. Thus, discussions about the introduction of novel nicotine-containing tobacco products in the market during the 1980s and 1990s helped shape the current regulation of tobacco and nicotine products.

New products introduced in the 1990s or later included modified tobacco cigarettes (e. g ., Advance, Omni); cigarette-like products, also called cigalikes (e.g., Eclipse, Accord); and smokeless tobacco products (e.g., Ariva, Exalt, Revel, snus). Advance, made by Brown and Williamson, was test-marketed with the slogan “All of the taste … Less of the toxins.” Vector launched a national advertising campaign for its Omni cigarette with the slogan “Reduced carcinogens. Premium taste.” In addition to the question of whether the claims were supported by sufficient evidence, scientists and tobacco control leaders raised concerns about the potential for adverse consequences associated with novel nicotine and tobacco products marketed for harm reduction, such as a reduction in cessation rates or increased experimentation by children ( Warner and Martin 2003 ; Joseph et al. 2004 ; Caraballo et al. 2006 ). Studies have shown that smokers are interested in trying novel “reduced-exposure” products and perceive them to have lower health risks, even when advertising messages do not make explicit health claims ( Hamilton et al. 2004 ; O’Connor et al. 2005 ; Caraballo et al. 2006 ; Choi et al. 2012 ; Pearson et al. 2012 ).

At FDA ’s request, the Institute of Medicine ( IOM [now the National Academy of Medicine]) convened a committee of experts to formulate scientific methods and standards by which potentially reduced-exposure products (PREPs), whether the purported reduction was pharmaceutical or tobacco related, could be assessed. The committee concluded that “[f]or many diseases attributable to tobacco use, reducing risk of disease by reducing exposure to tobacco toxicants is feasible” ( Stratton et al. 2001 , p. 232). However, it also cautioned that “PREPs have not yet been evaluated comprehensively enough (including for a sufficient time) to provide a scientific basis for concluding that they are associated with a reduced risk of dis ease compared to conventional tobacco use” ( Stratton et al. 2001 , p. 232). The committee added that “the major concern for public health is that tobacco users who might otherwise quit will use PREPs instead, or others may initiate smoking, feeling that PREPs are safe. That will lead to less harm reduction for a population (as well as less risk reduction for that individual) than would occur without the PREP , and possibly to an adverse effect on the population” ( Stratton et al. 2001 , p. 235). Subsequently, in 2006, Judge Kessler cited these findings in her decision which demanded the removal of light and low-tar labeling due to the misleading nature of these claims ( United States v. Philip Morris 2006 ).

• The E-Cigarette

Invention of the E-Cigarette

An early approximation of the current e-cigarette appeared in a U.S. patent application submitted in 1963 by Herbert A. Gilbert and was patented in August 1965 (U.S. Patent No. 3,200,819) ( Gilbert 1965 ). The application was for a “smokeless nontobacco cigarette,” with the aim of providing “a safe and harmless means for and method of smoking” by replacing burning tobacco and paper with heated, moist, flavored air. A battery-powered heating element would heat the flavor elements without combustion ( Gilbert 1965 ). The Favor cigarette, introduced in 1986, was another early noncombustible product promoted as an alternative nicotine-containing tobacco product ( United Press International 1986 ; Ling and Glantz 2005 ).

The first device in the recent innovation in e-cigarettes was developed in 2003 by the Chinese pharmacist Hon Lik, a former deputy director of the Institute of Chinese Medicine in Liaoning Province. Lik’s patent application described a kind of electronic atomizing cigarette ( Hon 2013 ). With support from Chinese investors, in 2004 the product was introduced on the Chinese market under the company name Ruyan ( Sanford and Goebel 2014 ). The product gained some attention among Chinese smokers early on as a potential cessation device or an alternative cigarette product.

The e-cigarette was part of the U.S. market by the mid-2000s, and by 2010 additional brands started to appear in the nation’s marketplace, including Ruyan and Janty ( Regan et al. 2013 ). Ruyan gained a U.S. patent for its product with the application stating that the product is “an electronic atomization cigarette that functions as substitutes (sic) for quitting smoking and cigarette substitutes.” (U.S. Patent No. 8,490,628 B2, 2013). In August 2013, Imperial Tobacco Group purchased the intellectual property behind the Ruyan e-cigarette for $75 million. As of 2014 an estimated 90% of the world’s production of e-cigarette technology and products came from mainland China, mainly Guangdong Province and Zhejiang Province ( Barboza 2014 ).

Sales of e-cigarettes in the United States have risen rapidly since 2007. Widespread advertising via television commercials and through print advertisements for popular brands, often featuring celebrities, has contributed to a large increase in e-cigarette use by both adults and youth since 2010 ( Felberbaum 2013 ; King et al. 2013 ; Regan et al. 2013 ). Additionally, marketing through social media, as well as other forms of Internet marketing, has been employed to market these devices ( Huang et al. 2014 ; Kim et al. 2014 ).

In 2013, an estimated 13.1 million middle school and high school students were aware of e-cigarettes ( Wang et al. 2014 ). According to data from the National Youth Tobacco Survey, in 2011 the prevalence of current e-cigarette use (defined as use during at least 1 day in the past 30 days) among high school students was 1.5%; prevalence increased dramatically, however, to 16% by 2015, surpassing the rate of conventional-cigarette use among high school students ( CDC 2016b ; see Chapter 2 ). This equates to 2.4 million high school students and 620,000 middle school students having used an e-cigarette at least one time in the past 30 days in 2015 ( CDC 2016b ).

These trends have led to substantial concern and discussion within public health communities, including state and national public health agencies, professional organizations, and school administrators and teachers. A primary concern is the potential for nicotine addiction among nonsmokers, especially youth and young adults, and that this exposure to nicotine among youth and young adults is harmful. The diversity and novelty of e-cigarette products on the market and ongoing product innovations make assessments of the biological effects of current e-cigarettes under actual conditions of use—such as their long-term harmfulness—difficult to measure. Unanswered questions remain about the risk profile of these devices, their potential use by young people as a first step to other nicotine products, and their total impact on public health. There are diverging opinions about the potential public health impact of these new products. Some public health scientists have highlighted the potential for alternative nicotine products to serve as a substitute for conventional cigarettes and thus a harm reduction tool ( Henningfield et al. 2003 ; Abrams 2014 ). Others have cautioned that the use of alternative nicotine products might become a bridge that may lead to greater tobacco product use—including dual- or multiple-product use—or initiate nicotine addiction among nonsmokers, especially youth ( Cobb et al. 2010 ; Wagener et al. 2012 ; Benowitz and Goniewicz 2013 ; Britton 2013 ; Chapman 2013 ; Etter 2013 ; USDHHS 2014 ). Current evidence is insufficient to reject either of these hypotheses.

E-Cigarette Products

Components and devices.

E-cigarette devices are composed of a battery, a reservoir for holding a solution that typically contains nicotine, a heating element or an atomizer, and a mouthpiece through which the user puffs ( Figure 1.2 ). The device heats a liquid solution (often called e-liquid or e-juice) into an aerosol that is inhaled by the user. E-liquid typically uses propylene glycol and/or glycerin as a solvent for the nicotine and flavoring chemicals

Parts of an e-cigarette device. Source: Photo by Mandie Mills, CDC.

Flavors and E-Cigarettes

The e-liquids in e-cigarettes are most often flavored; a study estimated that 7,700 unique flavors exist ( Zhu et al. 2014 ) and that most of them are fruit or candy flavors ( Figure 1.3 ). A content analysis of the products available via online retail websites documented that tobacco, mint, coffee, and fruit flavors were most common, followed by candy (e. g ., bubble gum), unique flavors (e.g., Belgian waffle), and alcoholic drink flavors (e.g., strawberry daiquiri) ( Grana and Ling 2014 ). Some retail stores are also manufacturers that create custom flavors, which increases the variety of flavors available.

Examples of e-liquid flavors. Source: Photo by Mandie Mills, CDC.

The widespread availability and popularity of flavored e-cigarettes is a key concern regarding the potential public health implications of the products. The concern, among youth, is that the availability of e-cigarettes with sweet flavors will facilitate nicotine addiction and simulated smoking behavior—which will lead to the use of conventional tobacco products ( Kong et al. 2015 ; Krishnan-Sarin et al. 2015 ). Flavors have been used for decades to attract youth to tobacco products and to mask the flavor and harshness of tobacco ( USDHHS 2012 ). Industry documents show that tobacco companies marketed flavored little cigars and cigarillos to youth and to African Americans to facilitate their uptake of cigarettes ( Kostygina et al. 2014 ). Companies also intended flavored smokeless tobacco products to facilitate “graduation” to unflavored products that more easily deliver more nicotine to the user ( USDHHS 2012 ). Various studies have shown that youth are more likely than adults to choose flavored cigarettes and cigars ( CDC 2015b ). Concern over these findings led Congress to include a ban on characterizing flavors for cigarettes, other than tobacco or menthol, in the Tobacco Control Act. A similar concern exists about e-cigarettes, and this concern is supported by studies indicating that youth and young adults who have ever used e-cigarettes begin their use with sweet flavors rather than tobacco flavors ( Kong et al. 2015 ; Krishnan-Sarin et al. 2015 ). Notably, 81.5% of current youth e-cigarette users said they used e-cigarettes “because they come in flavors I like” ( Ambrose et al. 2015 ).

E-Cigarette Devices

First-generation e-cigarettes were often similar in size and shape to conventional cigarettes, with a design that also simulated a traditional cigarette in terms of the colors used (e. g ., a white body with tan mouthpiece). These devices were often called cigalikes, but there were other products designed to simulate a cigar or pipe. Other cigalikes were slightly longer or narrower than a cigarette; they may combine white with tan or may be black or colored brightly. These newer models use a cartridge design for the part of the device that holds the e-liquid, which is either prefilled with the liquid or empty and ready to be filled. The user then squeezes drops of the e-liquid onto a wick (or bit of cotton or polyfil) connected to the heating element and atomizer ( Figure 1.4 ). As e-cigarettes have become more popular, their designs have become more diverse, as have the types of venues where they are sold ( Noel et al. 2011 ; Zhu et al. 2014 ).

E-liquids being poured into an e-cigarette device. Source: Photo by Mandie Mills, CDC.

Second-generation devices include products that are shaped like pens, are comparatively larger and cylindrical, and are often referred to as “tank systems” in a nod to the transparent reservoir that holds larger amounts of e-liquid than previous cartridge-containing models. Third- and fourth-generation devices represent a diverse set of products and, aesthetically, constitute the greatest departure from the traditional cigarette shape, as many are square or rectangular and feature customizable and rebuildable atomizers and batteries. In addition, since the beginning of the availability of e-cigarettes and their component parts, users have been modifying the devices or building their own devices, which are often referred to as “mods.” The differences in design and engineering of the products are key factors in the size, distribution, and amount of aerosol particles and the variability in levels of chemicals and nicotine present in the e-liquid/aerosol and delivered to the user ( Brown and Cheng 2014 ).

E-Cigarette Product Components and Risks

One of the primary features of the more recent generation of devices is that they contain larger batteries and are capable of heating the liquid to a higher temperature, potentially releasing more nicotine, forming additional toxicants, and creating larger clouds of particulate matter ( Bhatnagar et al. 2014 ; Kosmider et al. 2014 ). For instance, one study demonstrated that, at high temperatures (150°C), exceedingly high levels of formaldehyde—a carcinogen (found to be 10 times higher than at ambient temperatures)—are present that are formed through the heating of the e-liquid solvents (propylene glycol and glycerin), although the level of tolerance of actual users to the taste of the aerosol heated to this temperature is debated ( Kosmider et al. 2014 ; CDC 2015a ; Flavor and Extract Manufacturers Association of the United States 2015 ; Pankow et al. 2015 ). There is also concern regarding the safety of inhaling e-cigarette flavorings. Although some manufacturers have claimed their flavorants are generally recognized as safe for food additives (i.e., to be used in preparing foods for eating), little is known about the long-term health effects of inhaling these substances into the lungs ( CDC 2015a ).

Many devices can be readily customized by their users, which is also leading to the concern that these devices are often being used to deliver drugs other than nicotine ( Brown and Cheng 2014 ). Most commonly reported in the news media, on blogs, and by user anecdote is the use of certain types of e-cigarette-related products for delivering different forms of marijuana ( Morean et al. 2015 ; Schauer et al. 2016 ). The tank systems, for example, have been used with liquid tetrahydrocannabinol ( THC ) or hash oil. Some personal vaporizer devices can be used with marijuana plant material or a concentrated resin form of marijuana called “wax.” One study describes the use, in Europe, of e-cigarette devices to smoke marijuana ( Etter 2015 ).

The various e-cigarette products, viewed as a group, lack standardization in terms of design, capacity for safely holding e-liquid, packaging of the e-liquid, and features designed to minimize hazards with use ( Yang et al. 2014 ). All of these design features may have implications for the health impact of e-cigarette use. Notably, from 2010 to 2014, calls to poison control centers in the United States about exposures related to e-cigarettes increased dramatically. According to the American Association of Poison Control Centers (2015) , 271 cases were reported in 2011, but 3,783 calls were reported in 2014. Among all calls, 51% involved exposure among children younger than 5 years of age ( CDC 2014 ). Most poisonings appear to have been caused by exposure to nicotine-containing liquid ( CDC 2014 ). The lack of a requirement for child-resistant packaging for e-liquid containers may have contributed to these poisonings. Since these data were released, one death in the United States has been confirmed in a child who drank e-liquid containing nicotine ( Mohney 2014 ). Additionally, serious adverse reactions, including at least two deaths, have been reported to FDA in cases that could be attributed to the use of e-cigarettes ( FDA 2013 ). This increase in poisonings prompted the Child Nicotine Poisoning Prevention Act of 2015 (2016) , which was enacted in January 2016. This law requires any container of liquid nicotine that is sold, manufactured, distributed, or imported into the United States to be placed in packaging that is difficult to open by children under 5 years of age.

Secondary risks are also of concern regarding e-cigarettes, including passive exposure to nicotine and other chemicals, and adverse events due to device malfunction. Nicotine is a neuroteratogen, and its use by pregnant women exposes a developing fetus to risks that are well documented in the 50th-anniversary Surgeon General’s report on smoking ( USDHHS 2014 ) and include impaired brain development ( England et al. 2015 ) and other serious consequences. Finally, another consequence of the lack of device regulation is the occurrence of battery failures and subsequent explosions. Explosions have typically occurred during charging, resulting in house and car fires, and sometimes causing injuries to those involved. From 2009 to late 2014, 25 incidents of explosions and fires involving e-cigarettes occurred in the United States ( Chen 2013 ; U.S. Fire Administration 2014 ; FDA 2013 ).

• E-Cigarette Companies

E-cigarette companies include manufacturers, wholesalers, importers, retailers, distributors, and some other groups that overlap with these entities ( Barboza 2014 ; Whelan 2015 ). Currently, most of the products are manufactured in Shenzhen, Guangdong Province, China ( Cobb et al. 2010 ; Grana et al. 2014 ; Zhu et al. 2014 ). One study placed the number of brands at 466 in January 2014 and found a net increase of 10.5 brands per month ( Zhu et al. 2014 ). All the major tobacco companies (e. g ., Reynolds American, Altria; Table 1.1 ) and many smaller, independent companies are now in the business. When e-cigarettes first entered the U.S. market, they were sold primarily by independent companies via the Internet and in shopping malls at kiosks where those interested could sample the products. A unique feature of the e-cigarette industry, compared to other tobacco and nicotine products, is the recruitment of visitors to their websites as “affiliates” or distributors to help market the products and, in turn, receive commissions on sales ( Grana and Ling 2014 ; Cobb et al. 2015 ). For example, some companies offer a way for users to earn a commission by advertising the products (e.g., a banner ad is placed on one’s website, and when someone clicks on the link and subsequently purchases a product, the website owner gets a percentage commission). Some companies also offer rewards programs for recruiting new customers or for brand loyalty, with web-site users earning points for free or reduced-price products ( Richardson et al. 2015 ).

Multinational tobacco companies with e-cigarette brands.

E-cigarettes are now in widespread national distribution through convenience stores, tobacco stores, pharmacies, “big box” retail chains such as Costco, online retailers, and shops devoted to e-cigarette products (often called “vape shops”) ( Giovenco et al. 2015 ; Public Health Law Center 2015 ). The “vape shops” offer a place to buy customizable devices and e-liquid solutions in many flavors and sometimes include a café or other elements that promote socializing, essentially making such places like a lounge. With the rapid increase in distribution and marketing in the industry, sales have increased rapidly and were projected to reach $2.5 billion in 2014 and $3.5 billion in 2015, including projections for retail and online channels, as well as “vape shops” ( Wells Fargo Securities 2015 ).

The advertising and marketing of e-cigarette products has engendered skepticism among public health professionals and legislators, who have noted many similarities to the advertising claims and promotional tactics used for decades by the tobacco industry to sell conventional tobacco products ( Campaign for Tobacco-Free Kids 2013 ; CDC 2016a ). Indeed, several of the e-cigarette marketing themes have been reprised from the most memorable cigarette advertising, including those focused on freedom, rebellion, and glamor ( Grana and Ling 2014 ). E-cigarette products are marketed with a variety of unsubstantiated health and cessation messages, with some websites featuring videos of endorsements by physicians (another reprisal of old tobacco industry advertising) ( Grana and Ling 2014 ; Zhu et al. 2014 ). Unlike conventional cigarettes, for which advertising has been prohibited from radio and television since 1971, e-cigarette products are advertised on both radio and television, with many ads featuring celebrities. E-cigarettes also are promoted through sports and music festival sponsorships, in contrast to conventional cigarettes and smokeless tobacco products, which have been prohibited from such sponsorships since the Master Settlement Agreement in 1998. E-cigarettes also appear as product placements in television shows and movies ( Grana et al. 2011 ; Grana and Ling 2014 ).

Another key avenue for e-cigarette promotion is social media, such as Twitter, Facebook, YouTube, and Instagram. As is true in the tobacco industry, the e-cigarette industry organizes users through advocacy groups ( Noel et al. 2011 ; Harris et al. 2014 ; Saitta et al. 2014 ; Caponnetto et al. 2015 ). The extensive marketing and advocacy through various channels broadens exposure to e-cigarette marketing messages and products; such activity may encourage nonsmokers, particularly youth and young adults, to perceive e-cigarette use as socially normative. The plethora of unregulated advertising is of particular concern, as exposure to advertising for tobacco products among youth is associated with cigarette smoking in a dose-response fashion ( USDHHS 2012 ).

• Federal Regulation of E-Cigarettes

A “Two-Pronged” Approach to Comprehensive Tobacco Control

Since the passage of the Tobacco Control Act in 2009, FDA has had the authority to regulate the manufacturing, distribution, and marketing of tobacco products sold in the United States. FDA had immediate jurisdiction over cigarettes, roll-your-own cigarette tobacco, and smokeless tobacco. In May 2016, FDA asserted jurisdiction over products that meet the statutory definition of a tobacco product, including e-cigarettes, except accessories of these products ( Federal Register 2016 ). That regulation is currently under litigation.

The IOM ’s 2007 report, Ending the Tobacco Problem: A Blueprint for the Nation, established a “two-pronged” strategy for comprehensive tobacco control: (1) full implementation of proven, traditional tobacco control measures such as clean indoor air laws, taxation, and countermarketing campaigns; and (2) “strong federal regulation of tobacco products and their marketing and distribution” ( Bonnie et al. 2007 , p. 1).

Included in FDA ’s broad authority are the restriction of marketing and sales to youth, requiring disclosure of ingredients and harmful and potentially harmful constituents, setting product standards (e. g ., requiring the reduction or elimination of ingredients or constituents), requiring premarket approval of new tobacco products and review of modified-risk tobacco products, and requiring health warnings. The standard for FDA to use many of its regulatory authorities is whether such an action is appropriate for the protection of public health ( Federal Food, Drug, and Cosmetic Act , § 907(a)(3)(A)). The public health standard in the Tobacco Control Act also requires FDA to consider the health impact of certain regulatory actions at both the individual and population levels, including their impact on nonusers, and on initiation and cessation ( Federal Food, Drug, and Cosmetic Act , § 907(a)(3)(B)).

Importantly, the Tobacco Control Act preserves the authority of state, local, tribal, and territorial governments to enact any policy “in addition to, or more stringent than” requirements established under the Tobacco Control Act “relating to or prohibiting the sale, distribution, possession, exposure to, access to, advertising and promotion of, or use of tobacco products by individuals of any age” ( Federal Food, Drug, and Cosmetic Act , § 916(a)(1)). This preservation of state and local authority ensures the continuation of more local-level, comprehensive tobacco control. However, the statute expressly preempts states and localities from establishing or continuing requirements that are different from or in addition to FDA requirements regarding standards for tobacco products, premarket review, adulteration, misbranding, labeling, registration, good manufacturing practices, or modified-risk tobacco products ( Federal Food, Drug, and Cosmetic Act , § 916(a)(2)(A)). But this express preemption provision does not apply to state and local authority to impose requirements relating to the “sale, distribution, possession, information reporting to the State, exposure to, access to, the advertising and promotion of, or use of, tobacco products by individuals of any age …” ( Federal Food, Drug, and Cosmetic Act , § 916(a)(2)(b)). The interaction of these complex provisions related to federal preemption of state law has been the subject of challenges by the tobacco industry to state and local laws. Thus far, courts have upheld certain local ordinances restricting the sale of flavored tobacco products ( National Association of Tobacco Outlets, Inc. v. City of Providence 2013 ; U.S. Smokeless Tobacco Manufacturing Co. v. City of New York 2013 ).

Legal Basis for Regulating E-Cigarettes as Tobacco Products

In the United States, e-cigarettes can be regulated either as products marketed for therapeutic purposes or as tobacco products. Since the advent of e-cigarettes in the United States around 2007, manufacturers have had the option to apply to FDA ’s Center for Drug Evaluation and Research ( CDER ) or Center for Devices and Radiological Health (CDRH) for approval to market e-cigarettes for therapeutic purposes; as of August 2016, no e-cigarette manufacturers have received approval through this avenue.

In 2008 and early 2009, FDA detained multiple shipments of e-cigarettes from overseas manufacturers and denied them entry into the United States on the grounds that e-cigarettes were unapproved drug-device combination products ( FDA 2011 ). Sottera, Inc., which now does business as NJOY, challenged that determination ( Smoking Everywhere, Inc. and Sottera, Inc., d/b/a NJOY v. U.S. Food and Drug Administration, et al. 2010 ; Bloomberg Business 2015 ). Between the filing of the lawsuit and a decision on the motion for preliminary injunction, Congress passed the Tobacco Control Act and the President signed it into law. The Tobacco Control Act defines the term “tobacco product,” in part, as any product, including component parts or accessories, “made or derived from tobacco” that is not a “drug,” “device,” or “combination product” as defined by the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 321(rr)) ( Family Smoking Prevention and Tobacco Control Act 2009 , § 101(a)). The District Court subsequently granted a preliminary injunction relying on the Supreme Court’s decision in Brown and Williamson (1996) and the recently enacted Tobacco Control Act. FDA appealed the decision and the U.S. Court of Appeals for the D.C. Circuit held that e-cigarettes and, therefore, other products “made or derived from tobacco” are not drug/device combinations unless they are marketed for therapeutic purposes, but can be regulated by FDA as tobacco products under the Tobacco Control Act ( Sottera, Inc. v. Food & Drug Administration 2010 ).

On September 25, 2015, FDA proposed regulations to describe the circumstances in which a product made or derived from tobacco that is intended for human consumption will be subject to regulation as a drug, device, or a combination product. The comment period for this proposed regulation closed on November 24, 2015.

Most e-cigarettes marketed and sold in the United States today contain nicotine made or derived from tobacco. Although some e-cigarettes claim that they contain nicotine not derived from tobacco, or that they contain no nicotine at all ( Lempert et al. 2016 ), there may be reason to doubt some of these claims. Currently, synthetic nicotine and nicotine derived from genetically modified, nontobacco plants are cost-prohibitive for e-cigarette manufacturers, although technological advances could eventually increase the cost-effectiveness of using nicotine that was not derived from tobacco ( Lempert et al. 2016 ). The health effects of passive exposure to e-cigarettes with no nicotine, as well as their actual use and the extent of exposure to these products, have just begun to be studied ( Hall et al. 2014 ; Marini et al. 2014 ; Schweitzer et al. 2015 ) and some states and localities are taking steps to regulate e-cigarettes that do not contain nicotine or tobacco ( Lempert et al. 2016 ).

Deeming Rule

The Tobacco Control Act added a new chapter to the Federal Food, Drug, and Cosmetic Act , which provides FDA with authority over tobacco products. The new chapter applied immediately to all cigarettes, cigarette tobacco, roll-your-own tobacco, and smokeless tobacco; and the law included “any other tobacco products that the Secretary of Health and Human Services by regulation deems to be subject to this chapter” ( Federal Food, Drug, and Cosmetic Act , §901 (b)). Therefore, to regulate e-cigarettes as tobacco products, FDA was required to undertake a rulemaking process to extend its regulatory authority to include e-cigarettes.

• Prohibitions on adulterated and misbranded products;
• Required disclosure of existing health information, including lists of ingredients and documents on health effects;
• Required registration of manufacturers;
• Required disclosure of a list of all tobacco products, including information related to labeling and advertising;
• Premarket review of new tobacco products (i.e., those not on the market on February 15, 2007);
• Restrictions on products marketed with claims about modified risk.
• Minimum age restrictions to prevent sales to minors;
• Requirements to include a nicotine warning; and
• Prohibitions on vending machine sales, unless in a facility that never admits youth.

Future Regulatory Options

• Product standards, including restrictions on flavors;
• Restrictions on promotion, marketing, and advertising, and prohibitions on brand-name sponsorship of events;
• Minimum package sizes;
• Prohibitions on self-service displays;
• Child-resistant packaging and the inclusion of health warnings; and
• Regulation of nicotine levels in products.

Despite this broad authority, FDA is prohibited from certain regulatory actions, even if those actions may be appropriate for the protection of public health. Specifically, FDA generally cannot restrict tobacco use in public places, levy taxes on tobacco products, prohibit sales by a specific category of retail outlet (e. g ., pharmacies), completely eliminate nicotine in tobacco products, require prescriptions for tobacco products unless it is marketed for therapeutic purposes, or establish a federal minimum age of sale for tobacco products above 18 years of age. Thus, even if FDA fully exercises all of its existing authority over e-cigarettes, regulation will still need to be complemented at the state and local levels, including efforts previously shown to be effective for conventional tobacco products, such as comprehensive smokefree laws at the state and local levels, pricing strategies, raising the minimum age of sales to minors to 21, and high-impact countermarketing campaigns. In the current context of rising rates of use by youth, localities and states can also implement policies and programs that minimize the individual- and population-level harms of e-cigarettes (see Chapter 5 ).

This chapter presents the major conclusions of this Surgeon General’s report and the conclusions of each chapter. E-cigarettes are presented within their historical context, with an overview of the components of these devices and the types of products. In 2016, FDA announced its final rule to regulate e-cigarettes under the Family Smoking Prevention and Tobacco Control Act. The chapter outlines options for the regulation of e-cigarettes, particularly as they relate to youth and young adults, based on successful smoking policies. The need to protect youth and young adults from initiating or continuing the use of nicotine-containing products forms a strong basis for the need to regulate e-cigarettes at the local, state, and national levels in the future.

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Conclusions about the effects of electronic cigarettes remain the same

An updated Cochrane Review provides an independent, rigorous assessment of the best available evidence to date about electronic cigarettes for quitting smoking.

Scroll to the bottom of this article for a round-up of media coverage

The conclusions of this updated Review are unchanged since the last review was published two years ago: electronic cigarettes may help smokers stop their smoking, and the included studies did not find any serious side effects associated with their use for up to two years.

Many studies are now underway which may help us understand more about their effects in the future.

The first Cochrane Review, published in the Cochrane Library in December 2014, showed that electronic cigarettes may be an aid to smokers in stopping their smoking. The updated Review did not find any new randomized controlled trials (RCTs) with long-term outcomes looking at the effectiveness of electronic cigarettes in helping people to stop smoking. However, this is an active area of research, with a large number of ongoing studies that will add to the evidence in the next few years.   

Smoking is a significant global health problem. Despite many smokers wanting to stop, they often find it difficult to succeed in the long term. One of the most effective and widely used strategies to help combat the cravings associated with nicotine addiction is to deliver nicotine by patches and chewing gum.

Electronic cigarettes have been around in some form for a number of years, but over the past few years their popularity has increased significantly, and they have begun to look and feel less like conventional cigarettes. Unlike chewing gum and patches, they mimic the experience of cigarette smoking because they are hand-held and generate a smoke-like vapour when used.  They help to recreate similar sensations of smoking without exposing users or others to the smoke from conventional cigarettes, and can be used to provide smokers with nicotine. Though they are used by many smokers, little is still known about how effective they are at helping people stop smoking.

This version of the updated Cochrane Review includes no new RCTs. The original Review included two RCTs involving more than 600 participants, and found that electronic cigarettes containing nicotine may increase the chances of stopping smoking within six to 12 months, compared to using an electronic cigarette without nicotine. The researchers could not determine whether using electronic cigarettes was better than a nicotine patch in helping people stop smoking, because there were not enough people taking part in the study.

This updated Review now includes observational data from an additional 11 studies.  Of the studies which measured side effects, none found any serious side effects of using electronic cigarettes for up to two years. The studies showed that throat and mouth irritation are the most commonly reported side effects in the short to medium term (up to two years).

The lead author of this Cochrane Review, Jamie Hartmann-Boyce from the Cochrane Tobacco Addiction Group, said, “The randomized evidence on smoking cessation is unchanged since the last version of the Review. We are encouraged to find many studies are now underway, particularly as electronic cigarettes are an evolving technology. Since the last version of the Review, 11 new observational and uncontrolled studies have been published. In terms of quitting, these can’t provide the same information we get from randomized controlled trials, but they contribute further information on the side effects of using electronic cigarettes to quit smoking. None detected any serious side effects, but longer term data are needed.”

Read this Press Release in French, Spanish or Polish .

Editor’s notes Full citation: Hartmann-Boyce J, McRobbie H, Bullen C, Begh R, Stead LF, Hajek P. Electronic cigarettes for smoking cessation . Cochrane Database of Systematic Reviews 2016, Issue 9. Art. No.: CD010216. DOI: 10.1002/14651858.CD010216.pub3.

Cochrane Review Author contact details : [email protected]

For all media enquiries, please contact:

Jo Anthony Senior Media and Communications Officer, Cochrane M +44(0) 7582 726 634 E  [email protected] or [email protected]

About Cochrane Cochrane is a global independent network of researchers, professionals, patients, carers, and people interested in health. Cochrane produces reviews which study all of the best available evidence generated through research and make it easier to inform decisions about health. These are called systematic reviews. Cochrane is a not-for-profit organization with collaborators from more than 130 countries working together to produce credible, accessible health information that is free from commercial sponsorship and other conflicts of interest. Our work is recognized as representing an international gold standard for high quality, trusted information.

Find out more at cochrane.org  |  Follow us on twitter @cochranecollab

If you are a journalist or member of the press and wish to receive news alerts before their online publication or if you wish to arrange an interview with an author, please contact the Cochrane press office:  [email protected]

About Wiley Wiley is a global provider of knowledge and knowledge-enabled services that improve outcomes in areas of research, professional practice, and education. Through the Research segment, the Company provides digital and print scientific, technical, medical, and scholarly journals, reference works, books, database services, and advertising. The Professional Development segment provides digital and print books, online assessment and training services, and test prep and certification. In Education, Wiley provides education solutions including online program management services for higher education institutions and course management tools for instructors and students, as well as print and digital content. The Company's website can be accessed at http://www.wiley.com .

Selected Media Coverage:

E-cigarettes can help smokers quit, says study in The Guardian . Why can't scientists agree on e-cigarettes? blog post in The Guardian . E-Cigs Might Help Some Quit Smoking, New Study Reveals on Consumer Reports .

About Electronic Cigarettes (E-Cigarettes)

• E-cigarettes have the potential to benefit adults who smoke and who are not pregnant if used as a complete substitute for regular cigarettes and other smoked tobacco products.
• E-cigarettes are not safe for youth, young adults, pregnant adults, as well as adults who do not currently use tobacco products.
• While e-cigarettes have the potential to benefit some people and harm others, scientists still have a lot to learn about whether e-cigarettes are effective in helping adults quit smoking.
• If you’ve never smoked or used other tobacco products or e-cigarettes, don’t start.
• Additional research can help understand long-term health effects.

E-cigarettes are not safe for youth, young adults, and pregnant women, as well as adults who do not currently use tobacco products.

• What are e-cigarettes?

What is in e-cigarette aerosol?

• What are the health effects of using e-cigarettes?
• What are the risks of e-cigarettes?
• Are e-cigarettes less harmful than regular cigarettes?
• Can e-cigarettes help adults quit smoking cigarettes?
• Who is using e-cigarettes?

• E-cigarettes come in many shapes and sizes. Most have a battery, a heating element, and a place to hold a liquid.
• E-cigarettes produce an aerosol by heating a liquid that usually contains nicotine—the addictive drug in regular cigarettes, cigars, and other tobacco products—flavorings, and other chemicals that help to make the aerosol. Users inhale this aerosol into their lungs. Bystanders can also breathe in this aerosol when the user exhales into the air.
• E-cigarettes are known by many different names. They are sometimes called “e-cigs,” “e-hookahs,” “mods,” “vape pens,” “vapes,” “tank systems,” and “electronic nicotine delivery systems (ENDS).”
• Some e-cigarettes are made to look like regular cigarettes, cigars, or pipes. Some resemble pens, USB sticks, and other everyday items. Larger devices such as tank systems, or “mods,” do not resemble other tobacco products.
• Using an e-cigarette is sometimes called “vaping.”
• E-cigarettes can be used to deliver marijuana and other drugs.

Some e-cigarettes are made to look like regular cigarettes, cigars, or pipes. Some resemble pens, USB sticks, and other everyday items.

The e-cigarette aerosol that users breathe from the device and exhale can contain harmful and potentially harmful substances, including:

• Ultrafine particles that can be inhaled deep into the lungs
• Flavoring such as diacetyl, a chemical linked to a serious lung disease
• Volatile organic compounds
• Cancer-causing chemicals
• Heavy metals such as nickel, tin, and lead 1

It is difficult for consumers to know what e-cigarette products contain. For example, some e-cigarettes marketed as containing zero percent nicotine have been found to contain nicotine. 2

E-cigarettes are still fairly new, and scientists are still learning about their long-term health effects. Here is what we know now.

Most e-cigarettes contain nicotine, which has known health effects. 1

• Nicotine is highly addictive.
• Nicotine is toxic to developing fetuses.
• Nicotine can harm adolescent and young adult brain development, which continues into the early to mid-20s.
• Nicotine is a health danger for pregnant adults and their developing babies.

Besides nicotine, e-cigarette aerosol can contain substances that harm the body. 1

• This includes cancer-causing chemicals and tiny particles that reach deep into lungs. However, e-cigarette aerosol generally contains fewer harmful chemicals than smoke from burned tobacco products.

E-cigarettes can cause unintended injuries. 1

• The Food and Drug Administration (FDA) collects data to help address this issue. You can report an e-cigarette explosion, or any other unexpected health or safety issue with an e-cigarette, here .
• In addition, acute nicotine exposure can be toxic. Children and adults have been poisoned by swallowing, breathing, or absorbing e-cigarette liquid through their skin or eyes.

Most e-cigarettes contain nicotine, which is addictive and toxic to developing fetuses. Nicotine exposure can also harm adolescent and young adult brain development, which continues into the early to mid-20s. 1 E-cigarette aerosol can contain chemicals that are harmful to the lungs. And youth e-cigarette use is associated with the use of other tobacco products, including cigarettes.

For more information about the risks of e-cigarettes for young people, visit Quick Facts on the Risks of E-cigarettes for Kids, Teens, and Young Adults .

Yes—but that doesn’t mean e-cigarettes are safe. E-cigarette aerosol generally contains fewer toxic chemicals than the deadly mix of 7,000 chemicals in smoke from regular cigarettes . 3 However, e-cigarette aerosol is not harmless. It can contain harmful and potentially harmful substances, including nicotine, heavy metals like lead, volatile organic compounds, and cancer-causing agents. 1

E-cigarettes are not currently approved by the FDA as a quit smoking aid. The U.S. Preventive Services Task Force, a group of health experts that makes recommendations about preventive health care, has concluded that evidence is insufficient to recommend e-cigarettes for smoking cessation in adults, including pregnant adults. 3

However, e-cigarettes may help non-pregnant adults who smoke if used as a complete substitute for all cigarettes and other smoked tobacco products.

• To date, the few studies on the issue are mixed. A Cochrane Review found evidence from two randomized controlled trials that e-cigarettes with nicotine can help adults who smoke stop smoking in the long term compared with placebo (non-nicotine) e-cigarettes. 4 However, there are some limitations to the existing research, including the small number of trials, small sample sizes, and wide margins of error around the estimates.
• A recent CDC study [PDF – 197 KB]  found that many adults are using e-cigarettes in an attempt to quit smoking. 5 However, most adult e-cigarette users do not stop smoking cigarettes and are instead continuing to use both products (known as “dual use”). 7 Dual use is not an effective way to safeguard your health, whether you’re using e-cigarettes, smokeless tobacco, or other tobacco products in addition to regular cigarettes. Because smoking even a few cigarettes a day can be dangerous, 6 quitting smoking completely is very important to protect your health.

E-cigarettes are the most commonly used tobacco product among youth.

• In 2023, 2.13 million U.S. middle and high school students used e-cigarettes in the past 30 days, including 4.6% of middle school students and 10.0% of high school students. 9
• In 2022, 2.55 million U.S. middle and high school students used e-cigarettes in the past 30 days, including 3.3% of middle school students and 14.1%  of high school students. 9
• In 2021, 4.5% of U.S. adults currently used e-cigarettes. 10
• In 2019, among adults who currently used e-cigarettes overall, 36.9% also currently smoked cigarettes, 39.5% formerly smoked cigarettes, and 23.6% had never smoked cigarettes. 11
• Among adults who currently used e-cigarettes, the percentage who have never smoked cigarettes is highest among those aged 18–24 years (56.0%), and is lower in older age groups. 11
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Electronic Cigarettes and Their Technical Aspects Research Paper

Microwave plasma atomic emission spectroscopy (mp-aes), microwave accelerated reaction system (mars), glycerin in e-liquid, propylene glycol in e-liquid, nicotine in e-liquid.

The harmful elements in tobacco smoke enter the user’s nervous system, heart, and vital organs within a few seconds of the initial inhalation, affecting each part of the body. However, it is becoming more and more popular to inhale vaporized e-liquid, which is generally considered safer than conventional tobacco products. A propylene glycerol mixture with different nicotine and flavoring percentages is what makes up an electronic cigarette (Stratton et al., 2018). The two most harmful components of tobacco smoke, tar and carbon monoxide, are neither produced using e-cigarettes. Although e-cigarettes are subject to strict safety and quality regulations, they pose certain risks because they are only slightly safer than cigarettes (Uchiyama et al., 2020). This research paper analyses the working principle of microwave plasma atomic emission spectroscopy and microwave accelerated reaction systems. The uses of glycerin, propylene glycol, and nicotine in e-liquid are also evaluated in this paper.

By analyzing a sample’s electromagnetic spectrum or mass spectrum, atomic spectroscopy refers to various analytical methods employed to ascertain the sample’s fundamental makeup. A nuclear emission method is microwave plasma atomic emission spectroscopy (Balaram, 2020). It uses the feature that when an atom of a particular element is stimulated, it releases light in a distinctive range of wavelengths as it rebounds to the initial state (Jung et al., 2019). The inductively coupled argon plasma (ICP) and the microwave plasma (MP), both higher temperature generators and hence suitable stimulation sources for atomic emission spectroscopy, are transmitters of nuclear emission. Temperature readings in the nitrogen-fueled microwave plasma approach 5,000 K (Vudagandla et al., 2017). Atomic emission is substantial at these levels, resulting in suitable identification ranges and linear dynamic spectrum for most components.

As a less expensive and safer option than Flame Atomic Absorption Spectrometry (FAAS) for multi-element evaluation of organic materials, Microwave Plasma Atomic Emission Spectrometry is gaining popularity. The existence of a FAAS flame is a hazard for labs using organic solvents and necessitates regular surveillance (Ozbek, 2018). MP-AES utilizes magnetically linked microwave radiation to create a stable and reliable plasma that may be used to detect critical elements in organic solvents directly (Münzel et al., 2020). The benefits of MP-AES include simplicity of use, excellent performance for challenging organic materials, and a safe approach with minimal operating costs (Qudus et al., 2021). Individual element assessment and the usage of combustible gases like C 2 H 2 and oxidizing gas N 2 O for certain elements are drawbacks of the procedure.

An invention for solvent recovery of environmental contaminants from solid matrices is the Microwave-Accelerated Reaction System (MARS). It is the procedure of separating chemicals from the specimen to the solvent after heating solid sample-solvent combinations using microwave radiation in a closed system (Bizzi et al., 2017). The MARS is equipped to perform solvent separation for organic assessment and acid digesting for inorganic evaluation. MARS is made for usage in laboratories and may be used to extract, dissolve, hydrolyze, or dry a variety of organic compounds (Chew et al., 2019). It is a technology for quick sample preparations for many different analytical techniques. The extraction is carried out in a closed vessel microwave heating technology with temperature and pressure controls.

The illustration below shows the microwave system’s main elements, including the magnetron, mode stirrer, isolator, cavity, and waveguide. A microwave powering system on the MARS has a tunable output range of 0 to 1500 watts, plus or minus 5% (Kumar et al., 2020). The magnetron produces microwave radiation, which travels via the waveguide and is injected into the pit. The mode stirrer disperses the energy in different directions, and the hole serves as a confinement container until the material load inside the cavity consumes the power (Nomanbhay & Ong, 2017). The magnetron is shielded from radiation that is not captured by the sampling load by the isolator. Energy may go through the transformer to the pits with the help of the isolator, but it cannot return from the hole to the magnetron.

Most e-liquids are manufactured with a base liquid such as vegetable glycerin, flavorings, and nicotine. According to Akshay (2020), the Food and Drug Association in the United States recognizes flavorings as acceptable for oral intake, sure of the components, such as 2,3-Pentanedione, acetoin, and cinnamaldehyde, are known to inflict irreparable lung damage. Although these substances are acceptable for use in food and beverages, they harm the respiratory system when inhaled (Ind, 2020). Vegetable glycerin, commonly known as glycerol, is an unscented, delightful solution that is colorless or yellowish and naturally occurs in certain living things. Many businesses, including the pharmaceutical and aesthetic sectors, use glycerin (Gotts et al., 2019). Vegetable glycerin can moisten the skin and ease constipation, among other advantages, although these advantages depend on how it is administered.

Sugar alcohol generated from plants, animals, or petroleum is known as glycerin. The kind derived from plant oils is called vegetable glycerin (Soogan et al., 2018). It is believed to have been found by accident more than 200 years ago when lead monoxide and olive oil were heated together. However, it was not until the mid-1900s, when it was initially utilized to produce dynamite, that it started to gain commercial and industrial significance (Woodall et al., 2020). Vegetable glycerin is made by pressing or combining a concentrated alkali, such as lye, with triglyceride-rich vegetable oils, like palm, soy, and coconut fats. This enables the glycerin to separate from the fatty compounds and combine with water to create an unscented, syrup-like liquid with a delicious flavor (Chun et al., 2017). Inflammation of the respiratory system can result from prolonged use of vaping or e-cigarettes, which contain vegetable glycerin. Consuming more glycerin in e-cigarettes is harmful and fatal to the human body.

Organic chemical propylene glycol (PG) is non-toxic and safe for human ingestion. Years ago, cereal, cheese, soft drinks, and ice cream were a few of the commercially accessible foods that contained propylene glycol as a food ingredient (Cotta et al., 2017). Based on e-liquids, propylene glycol gives e-cigarettes their throat sensation and vapor clouds. To keep the components of the e-liquid blended, propylene glycol, a thin, flavorless liquid, is utilized in e-cigarettes (Harvanko et al., 2019). However, propylene glycol levels rise in the blood of e-cigarette users who smoke twice daily for a month, which is harmful (Li et al., 2020). Propylene glycol creates smaller vapor clouds than vegetable glycerin because of its lower density.

When Charles-Adolphe Wurtz originally described propylene glycol in 1859, it was first thought that it would be used in medicinal formulations. It was suggested to swap out ethylene glycol with another substance to act as a solvent and delivery system for a bismuth substance employed to combat syphilis (Martinelli et al., 2019). Comparing propylene glycol to ethylene glycol, which can potentially have adverse effects and even fatal results, short- and long-term pharmacological tests have demonstrated that PG has a minimal side effect when employed as solvents in food and medicines (McGowan et al., 2018). It has a strong affinity for water and readily dissolves in substances including water, ether, glycerol, chloroform, ethyl and methyl alcohols, and ethyl acetate (Smith et al., 2020). Overall, propylene glycol possesses all of ethylene glycol’s great solvent qualities.

A nicotine-containing vapor is what electronic cigarettes are made to offer to the consumer. Commercially accessible e-liquids range from having little to a lot of nicotine. The chemical, which accounts for around 95% of the alkaloid’s composition of combustion in traditional cigarettes and 1% of the volume of cigarette tobacco, is the most prevalent tobacco alkaloid (Hajek et al., 2019). Although some e-liquids are nicotine-free, most are, and e-cigarette nicotine levels can vary (Tiwari et al., 2020). The amount of nicotine present in e-cigarette discharges is a significant factor in determining systemic sensitivity to nicotine and probably has a direct bearing on the misuse potential of e-cigarettes (Bhatt et al., 2020). It is anticipated that the device attributes that change the aerosol’s nicotine content will similarly change how easily e-cigarettes may be abused.

Most e-cigarettes contain nicotine, which is very addictive. The brain and body of e-cigarette users become used to nicotine over time, so once they stop vaping, they may experience nicotine withdrawal problems (Marques et al., 2021). It is challenging to stop using nicotine because of physical and psychological issues. Nicotine releases dopamine in the same brain parts where other addictive substances act (McGrath-Morrow et al., 2020). It brings about changes in mood that enable the individual to feel pleasant momentarily. Smoke is particularly addicting since it takes only 20 seconds for nicotine to reach the brain after inhalation (Picciotto & Kenny, 2020). Pulse rate, cardiac muscle oxygen absorption level, and ventricular pulse pressure all rise with nicotine addiction, causing various respiratory diseases. Nicotine concentrations in the central nervous system decrease after a smoker quits. This alteration sets off the mechanisms that lead to the pattern of desires and impulses that sustains addiction.

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The Risks of Another Epidemic: Teenage Vaping

“We’re stepping backward from all the advances we’ve made in tobacco control,” one investigator said.

By Jane E. Brody

While most of us strive to avoid inhaling aerosols that could harbor a deadly virus, millions of teens and young adults are deliberately bathing their lungs in aerosols rich in chemicals with known or suspected health hazards.

I’m referring to vaping (or “ juuling ”): the use of e-cigarettes that is hooking young people on a highly addictive drug — nicotine — and will be likely to keep them hooked for decades. Meanwhile, e-cigarettes and other vaping devices are legally sold with few restrictions while producers and sellers reap the monetary rewards. Although many states prohibit e-cigarette sales to persons younger than 18 or 21, youngsters have little trouble accessing the products online or from friends and relatives.

In just one year, from 2017 to 2018, vaping by high school seniors increased more than “for any substance we’ve ever monitored in 45 years, and the next year it rose again almost as much,” said Richard Miech, principal investigator for the national survey Monitoring the Future.

By 2019, a quarter of 12th graders were vaping nicotine, nearly half of them daily. Daily vaping rose in all three grades surveyed — eighth, 10th and 12th — “with accompanying increases in the proportions of youth who are physically addicted to nicotine,” Dr. Miech and colleagues reported in The New England Journal of Medicine last year.

Although self-reported use of e-cigarettes by high school and middle school students decreased over the past year, Dr. Robert R. Redfield, director of the Centers for Disease Control and Prevention, cautioned, “Youth e-cigarette use remains an epidemic.”

“We’re stepping backward from all the advances we’ve made in tobacco control,” Dr. Miech, professor at the Institute for Social Research at the University of Michigan, said in an interview. “I’m worried that we will eventually return to the tobacco situation of yore. There’s evidence that kids who vape are four to five times more likely the next year to experiment with cigarettes for the first time.”

As someone who witnessed the persuasive tactics the tobacco industry used to get nearly half of American adults hooked on regular cigarettes in the 1950s, I see similar efforts being used today to promote these new delivery systems for nicotine: sex, glamour, endorsements by celebrities and doctors, and sponsorship of popular sports and musical events. Only now there are even more pervasive avenues of influence through websites and social media.

In 2016, ads for e-cigarettes reached nearly four in five middle and high school students in the United States, Dr. Ellen S. Rome noted.

As in decades past, the nation’s regulatory agencies have been slow — some say negligent — to recognize this fast-growing threat to the health and development of young Americans. Dr. Rome, a pediatrician who heads the Center for Adolescent Medicine at the Cleveland Clinic, explained that nicotine forms addictive pathways in the brain that can increase a youngster’s susceptibility to addiction throughout life. The adolescent brain is still developing, she told me, and e-cigarette use is often a gateway to vaping of marijuana, which can affect the brain centers responsible for attention, memory, learning, cognition, self-control and decision-making.

In a review published last December in the Cleveland Clinic Journal of Medicine, Dr. Rome and her co-author, Perry Dinardo, challenged the public perception that vaping is harmless, or “at least less harmful than cigarette smoking.”

While it’s likely to be true that vaping may be less hazardous than tobacco cigarettes, since the vaped aerosols that reach the lungs are devoid of the thousands of tobacco-derived toxic and carcinogenic substances inhaled by cigarette smokers, vaping still introduces a fair share of potentially harmful chemicals. In addition to nicotine, some of the chemicals, like the carcinogen formaldehyde, are created when the nicotine-rich liquid in some vaping devices is heated to high temperatures.

“E-cigarettes might have their own unique health effects we haven’t discovered yet,” said Theodore L. Wagener, director of the Center for Tobacco Research at Ohio State University. “Although compared to tobacco cigarettes, e-cigarettes without a doubt expose users to much lower levels of harmful chemicals , we still don’t know how the body handles them and what their long-term effects might be.”

Remember, it took many decades of smoking by tens of millions of people before the deadly hazards of tobacco cigarettes were recognized.

The surge in the use of electronic cigarettes was tied to a game-changing product, Juul, a cartridge device introduced in 2017 in a slew of enticing flavors. Flavors especially attractive to youngsters are now banned from use in closed-system devices like Juul , which now is sold only in tobacco and menthol flavors, but can still be used in the open-system products sold in vape shops. And now, taking advantage of a loophole in regulations, a disposable product called Puff Bar , which comes in more than 20 flavors, has replaced Juul as the vape of choice among young people.

Concerns about vaping grew after a 2019 outbreak of severe lung injuries , which were subsequently linked to vitamin E acetate, an additive found in some vaping devices that deliver THC, the psychoactive ingredient in marijuana. Juul pods are not designed to be refillable with substances like THC or other chemicals.

Producers of Juul introduced changes that enhanced the palatability and safety of vaping, but at the same time “made it easier for kids to start using nicotine,” Dr. Wagener said. Instead of freebase nicotine that is very harsh to inhale, Juul contains a nicotine salt, “a very palatable form of nicotine that makes inhaling high doses of nicotine easy,” he explained. And Juul doesn’t require the high temperatures that produce toxic substances like formaldehyde. A single pod contains the nicotine equivalent of a pack of conventional cigarettes.

“Juul made it cool, and young people who had never smoked cigarettes are becoming addicted to nicotine ,” said Erika R. Cheng, a public health epidemiologist at Indiana University School of Medicine. In addition to nicotine, Juul pods contain a mix of glycerol, propylene glycol, benzoic acid and flavoring agents, the long-term health effects of which have yet to be determined , she said.

“E-cigarettes were initially advertised as a means to help people transition from harmful tobacco smoking,” Dr. Cheng said. “A lot of early users didn’t even know they contained nicotine.” Although a small minority of smokers have used e-cigarettes to help them quit or reduce their dependence on tobacco, most who use the devices vape to get their nicotine fix when they can’t smoke regular cigarettes.

Although there have been calls for bans on e-cigarettes, Abigail S. Friedman, a health economist at Yale University School of Public Health, cautioned that “bans can push people into the black market looking for something that can be acutely dangerous.”

Dr. Friedman said that rather than outright bans that can have unanticipated costs, she favors better regulations. Currently, other than flavors, what is inhaled from e-cigarettes is unregulated. Still, she and other experts are very concerned about the explosive uptake of vaping by young people. In the 2019 Youth Risk Behavior Survey of 4.9 million high school students, she said, 6 percent reported smoking conventional cigarettes while 33 percent puffed e-cigarettes in the past 30 days. In December 2018, the U.S. Surgeon General, Dr. Jerome Adams, declared e-cigarette use by youth an epidemic .

Jane Brody is the Personal Health columnist, a position she has held since 1976. She has written more than a dozen books including the best sellers “Jane Brody’s Nutrition Book” and “Jane Brody’s Good Food Book.” More about Jane E. Brody

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• Published: 18 May 2021

An updated overview of e-cigarette impact on human health

• Patrice Marques   ORCID: orcid.org/0000-0003-0465-1727 1 , 2 ,
• Laura Piqueras   ORCID: orcid.org/0000-0001-8010-5168 1 , 2 , 3 &
• Maria-Jesus Sanz   ORCID: orcid.org/0000-0002-8885-294X 1 , 2 , 3  

Respiratory Research volume  22 , Article number:  151 ( 2021 ) Cite this article

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The electronic cigarette ( e-cigarette ), for many considered as a safe alternative to conventional cigarettes, has revolutionised the tobacco industry in the last decades. In e-cigarettes , tobacco combustion is replaced by e-liquid heating, leading some manufacturers to propose that e-cigarettes have less harmful respiratory effects than tobacco consumption. Other innovative features such as the adjustment of nicotine content and the choice of pleasant flavours have won over many users. Nevertheless, the safety of e-cigarette consumption and its potential as a smoking cessation method remain controversial due to limited evidence. Moreover, it has been reported that the heating process itself can lead to the formation of new decomposition compounds of questionable toxicity. Numerous in vivo and in vitro studies have been performed to better understand the impact of these new inhalable compounds on human health. Results of toxicological analyses suggest that e-cigarettes can be safer than conventional cigarettes, although harmful effects from short-term e-cigarette use have been described. Worryingly, the potential long-term effects of e-cigarette consumption have been scarcely investigated. In this review, we take stock of the main findings in this field and their consequences for human health including coronavirus disease 2019 (COVID-19).

Electronic nicotine dispensing systems (ENDS), commonly known as electronic cigarettes or e-cigarettes , have been popularly considered a less harmful alternative to conventional cigarette smoking since they first appeared on the market more than a decade ago. E-cigarettes are electronic devices, essentially consisting of a cartridge, filled with an e-liquid, a heating element/atomiser necessary to heat the e-liquid to create a vapour that can be inhaled through a mouthpiece, and a rechargeable battery (Fig.  1 ) [ 1 , 2 ]. Both the electronic devices and the different e-liquids are easily available in shops or online stores.

Effect of the heating process on aerosol composition. Main harmful effects documented. Several compounds detected in e-cigarette aerosols are not present in e-liquid s and the device material also seems to contribute to the presence of metal and silicate particles in the aerosols. The heating conditions especially on humectants, flavourings and the low-quality material used have been identified as the generator of the new compounds in aerosols. Some compounds generated from humectants (propylene glycol and glycerol) and flavourings, have been associated with clear airways impact, inflammation, impairment of cardiovascular function and toxicity. In addition, some of them are carcinogens or potential carcinogens

The e-liquid typically contains humectants and flavourings, with or without nicotine; once vapourised by the atomiser, the aerosol (vapour) provides a sensation similar to tobacco smoking, but purportedly without harmful effects [ 3 ]. However, it has been reported that the heating process can lead to the generation of new decomposition compounds that may be hazardous [ 4 , 5 ]. The levels of nicotine, which is the key addictive component of tobacco, can also vary between the commercially available e-liquids, and even nicotine-free options are available. For this particular reason, e-cigarettes are often viewed as a smoking cessation tool, given that those with nicotine can prevent smoking craving, yet this idea has not been fully demonstrated [ 2 , 6 , 7 ].

Because e-cigarettes are combustion-free, and because most of the damaging and well-known effects of tobacco are derived from this reaction, there is a common and widely spread assumption that e-cigarette consumption or “vaping” is safer than conventional cigarette smoking. However, are they risk-free? Is there sufficient toxicological data on all the components employed in e-liquids ? Do we really know the composition of the inhaled vapour during the heating process and its impact on health? Can e-cigarettes be used to curb tobacco use? Do their consumption impact on coronavirus disease 2019 (COVID-19)? In the present review, we have attempted to clarify these questions based on the existing scientific literature, and we have compiled new insights related with the toxicity derived from the use of these devices.

Effect of e-cigarette vapour versus conventional cigarette exposure: in vivo and in vitro effects

Numerous studies have been performed to evaluate the safety/toxicity of e-cigarette use both in vivo and in in vitro cell culture.

One of the first studies in humans involved the analysis of 9 volunteers that consumed e-cigarettes , with or without nicotine, in a ventilated room for 2 h [ 8 ]. Pollutants in indoor air, exhaled nitric oxide (NO) and urinary metabolite profiles were analysed. The results of this acute experiment revealed that e-cigarettes are not emission-free, and ultrafine particles formed from propylene glycol (PG) could be detected in the lungs. The study also suggested that the presence of nicotine in e-cigarettes increased the levels of NO exhaled from consumers and provoked marked airway inflammation; however, no differences were found in the levels of exhaled carbon monoxide (CO), an oxidative stress marker, before and after e-cigarette consumption [ 8 ]. A more recent human study detected significantly higher levels of metabolites of hazardous compounds including benzene, ethylene oxide, acrylonitrile, acrolein and acrylamide in the urine of adolescent dual users ( e-cigarettes and conventional tobacco consumers) than in adolescent e-cigarette -only users (Table 1 ) [ 9 ]. Moreover, the urine levels of metabolites of acrylonitrile, acrolein, propylene oxide, acrylamide and crotonaldehyde, all of which are detrimental for human health, were significantly higher in e-cigarette -only users than in non-smoker controls, reaching up to twice the registered values of those from non-smoker subjects (Table 1 ) [ 9 ]. In line with these observations, dysregulation of lung homeostasis has been documented in non-smokers subjected to acute inhalation of e-cigarette aerosols [ 10 ].

Little is known about the effect of vaping on the immune system. Interestingly, both traditional and e-cigarette consumption by non-smokers was found to provoke short-term effects on platelet function, increasing platelet activation (levels of soluble CD40 ligand and the adhesion molecule P-selectin) and platelet aggregation, although to a lesser extent with e-cigarettes [ 11 ]. As found with platelets, the exposure of neutrophils to e-cigarette aerosol resulted in increased CD11b and CD66b expression being both markers of neutrophil activation [ 12 ]. Additionally, increased oxidative stress, vascular endothelial damage, impaired endothelial function, and changes in vascular tone have all been reported in different human studies on vaping [ 13 , 14 , 15 , 16 , 17 ]. In this context, it is widely accepted that platelet and leukocyte activation as well as endothelial dysfunction are associated with atherogenesis and cardiovascular morbidity [ 18 , 19 ]. In line with these observations the potential association of daily e-cigarettes consumption and the increased risk of myocardial infarction remains controversial but benefits may occur when switching from tobacco to chronic e-cigarette use in blood pressure regulation, endothelial function and vascular stiffness (reviewed in [ 20 ]). Nevertheless, whether or not e-cigarette vaping has cardiovascular consequences requires further investigation.

More recently, in August 2019, the US Centers for Disease Control and Prevention (CDC) declared an outbreak of the e-cigarette or vaping product use-associated lung injury (EVALI) which caused several deaths in young population (reviewed in [ 20 ]). Indeed, computed tomography (CT scan) revealed local inflammation that impaired gas exchange caused by aerosolised oils from e-cigarettes [ 21 ]. However, most of the reported cases of lung injury were associated with use of e-cigarettes for tetrahydrocannabinol (THC) consumption as well as vitamin E additives [ 20 ] and not necessarily attributable to other e-cigarette components.

On the other hand, in a comparative study of mice subjected to either lab air, e-cigarette aerosol or cigarette smoke (CS) for 3 days (6 h-exposure per day), those exposed to e-cigarette aerosols showed significant increases in interleukin (IL)-6 but normal lung parenchyma with no evidence of apoptotic activity or elevations in IL-1β or tumour necrosis factor-α (TNFα) [ 22 ]. By contrast, animals exposed to CS showed lung inflammatory cell infiltration and elevations in inflammatory marker expression such as IL-6, IL-1β and TNFα [ 22 ]. Beyond airway disease, exposure to aerosols from e-liquids with or without nicotine has also been also associated with neurotoxicity in an early-life murine model [ 23 ].

Results from in vitro studies are in general agreement with the limited number of in vivo studies. For example, in an analysis using primary human umbilical vein endothelial cells (HUVEC) exposed to 11 commercially-available vapours, 5 were found to be acutely cytotoxic, and only 3 of those contained nicotine [ 24 ]. In addition, 5 of the 11 vapours tested (including 4 that were cytotoxic) reduced HUVEC proliferation and one of them increased the production of intracellular reactive oxygen species (ROS) [ 24 ]. Three of the most cytotoxic vapours—with effects similar to those of conventional high-nicotine CS extracts—also caused comparable morphological changes [ 24 ]. Endothelial cell migration is an important mechanism of vascular repair than can be disrupted in smokers due to endothelial dysfunction [ 25 , 26 ]. In a comparative study of CS and e-cigarette aerosols, Taylor et al . found that exposure of HUVEC to e-cigarette aqueous extracts for 20 h did not affect migration in a scratch wound assay [ 27 ], whereas equivalent cells exposed to CS extract showed a significant inhibition in migration that was concentration dependent [ 27 ].

In cultured human airway epithelial cells, both e-cigarette aerosol and CS extract induced IL-8/CXCL8 (neutrophil chemoattractant) release [ 28 ]. In contrast, while CS extract reduced epithelial barrier integrity (determined by the translocation of dextran from the apical to the basolateral side of the cell layer), e-cigarette aerosol did not, suggesting that only CS extract negatively affected host defence [ 28 ]. Moreover, Higham et al . also found that e-cigarette aerosol caused IL-8/CXCL8 and matrix metallopeptidase 9 (MMP-9) release together with enhanced activity of elastase from neutrophils [ 12 ] which might facilitate neutrophil migration to the site of inflammation [ 12 ].

In a comparative study, repeated exposure of human gingival fibroblasts to CS condensate or to nicotine-rich or nicotine-free e-vapour condensates led to alterations in morphology, suppression of proliferation and induction of apoptosis, with changes in all three parameters greater in cells exposed to CS condensate [ 29 ]. Likewise, both e-cigarette aerosol and CS extract increased cell death in adenocarcinomic human alveolar basal epithelial cells (A549 cells), and again the effect was more damaging with CS extract than with e-cigarette aerosol (detrimental effects found at 2 mg/mL of CS extract vs. 64 mg/mL of e-cigarette extract) [ 22 ], which is in agreement with another study examining battery output voltage and cytotoxicity [ 30 ].

All this evidence would suggest that e-cigarettes are potentially less harmful than conventional cigarettes (Fig.  2 ) [ 11 , 14 , 22 , 24 , 27 , 28 , 29 ]. Importantly, however, most of these studies have investigated only short-term effects [ 10 , 14 , 15 , 22 , 27 , 28 , 29 , 31 , 32 ], and the long-term effects of e-cigarette consumption on human health are still unclear and require further study.

Comparison of the degree of harmful effects documented from e-cigarette and conventional cigarette consumption. Human studies, in vivo mice exposure and in vitro studies. All of these effects from e-cigarettes were documented to be lower than those exerted by conventional cigarettes, which may suggest that e-cigarette consumption could be a safer option than conventional tobacco smoking but not a clear safe choice

Consequences of nicotine content

Beyond flavour, one of the major issues in the e-liquid market is the range of nicotine content available. Depending on the manufacturer, the concentration of this alkaloid can be presented as low , medium or high , or expressed as mg/mL or as a percentage (% v/v). The concentrations range from 0 (0%, nicotine-free option) to 20 mg/mL (2.0%)—the maximum nicotine threshold according to directive 2014/40/EU of the European Parliament and the European Union Council [ 33 , 34 ]. Despite this normative, however, some commercial e-liquids have nicotine concentrations close to 54 mg/mL [ 35 ], much higher than the limits established by the European Union.

The mislabelling of nicotine content in e-liquids has been previously addressed [ 8 , 34 ]. For instance, gas chromatography with a flame ionisation detector (GC-FID) revealed inconsistencies in the nicotine content with respect to the manufacturer´s declaration (average of 22 ± 0.8 mg/mL vs. 18 mg/mL) [ 8 ], which equates to a content ~ 22% higher than that indicated in the product label. Of note, several studies have detected nicotine in those e-liquids labelled as nicotine-free [ 5 , 35 , 36 ]. One study detected the presence of nicotine (0.11–6.90 mg/mL) in 5 of 23 nicotine-free labelled e-liquids by nuclear magnetic resonance spectroscopy [ 35 ], and another study found nicotine (average 8.9 mg/mL) in 13.6% (17/125) of the nicotine-free e-liquids as analysed by high performance liquid chromatography (HPLC) [ 36 ]. Among the 17 samples tested in this latter study 14 were identified to be counterfeit or suspected counterfeit. A third study detected nicotine in 7 of 10 nicotine-free refills, although the concentrations were lower than those identified in the previous analyses (0.1–15 µg/mL) [ 5 ]. Not only is there evidence of mislabelling of nicotine content among refills labelled as nicotine-free, but there also seems to be a history of poor labelling accuracy in nicotine-containing e-liquids [ 37 , 38 ].

A comparison of the serum levels of nicotine from e-cigarette or conventional cigarette consumption has been recently reported [ 39 ]. Participants took one vape from an e-cigarette , with at least 12 mg/mL of nicotine, or inhaled a conventional cigarette, every 20 s for 10 min. Blood samples were collected 1, 2, 4, 6, 8, 10, 12 and 15 min after the first puff, and nicotine serum levels were measured by liquid chromatography-mass spectrometry (LC–MS). The results revealed higher serum levels of nicotine in the conventional CS group than in the e-cigarette group (25.9 ± 16.7 ng/mL vs. 11.5 ± 9.8 ng/mL). However, e-cigarettes containing 20 mg/mL of nicotine are more equivalent to normal cigarettes, based on the delivery of approximately 1 mg of nicotine every 5 min [ 40 ].

In this line, a study compared the acute impact of CS vs. e-cigarette vaping with equivalent nicotine content in healthy smokers and non-smokers. Both increased markers of oxidative stress and decreased NO bioavailability, flow-mediated dilation, and vitamin E levels showing no significant differences between tobacco and e-cigarette exposure (reviewed in [ 20 ]). Inasmuch, short-term e-cigarette use in healthy smokers resulted in marked impairment of endothelial function and an increase in arterial stiffness (reviewed in [ 20 ]). Similar effects on endothelial dysfunction and arterial stiffness were found in animals when they were exposed to e-cigarette vapor either for several days or chronically (reviewed in [ 20 ]). In contrast, other studies found acute microvascular endothelial dysfunction, increased oxidative stress and arterial stiffness in smokers after exposure to e-cigarettes with nicotine, but not after e-cigarettes without nicotine (reviewed in [ 20 ]). In women smokers, a study found a significant difference in stiffness after smoking just one tobacco cigarette, but not after use of e-cigarettes (reviewed in [ 20 ]).

It is well known that nicotine is extremely addictive and has a multitude of harmful effects. Nicotine has significant biologic activity and adversely affects several physiological systems including the cardiovascular, respiratory, immunological and reproductive systems, and can also compromise lung and kidney function [ 41 ]. Recently, a sub-chronic whole-body exposure of e-liquid (2 h/day, 5 days/week, 30 days) containing PG alone or PG with nicotine (25 mg/mL) to wild type (WT) animals or knockout (KO) mice in α7 nicotinic acetylcholine receptor (nAChRα7-KO) revealed a partly nAChRα7-dependent lung inflammation [ 42 ]. While sub-chronic exposure to PG/nicotine promote nAChRα7-dependent increased levels of different cytokines and chemokines in the bronchoalveolar lavage fluid (BALF) such as IL-1α, IL-2, IL-9, interferon γ (IFNγ), granulocyte-macrophage colony-stimulating factor (GM-CSF), monocyte chemoattractant protein-1 (MCP-1/CCL2) and regulated on activation, normal T cell expressed and secreted (RANTES/CCL5), the enhanced levels of IL-1β, IL-5 and TNFα were nAChRα7 independent. In general, most of the cytokines detected in BALF were significantly increased in WT mice exposed to PG with nicotine compared to PG alone or air control [ 42 ]. Some of these effects were found to be through nicotine activation of NF-κB signalling albeit in females but not in males. In addition, PG with nicotine caused increased macrophage and CD4 + /CD8 + T-lymphocytes cell counts in BALF compared to air control, but these effects were ameliorated when animals were sub-chronically exposed to PG alone [ 42 ].

Of note, another study indicated that although RANTES/CCL5 and CCR1 mRNA were upregulated in flavour/nicotine-containing e-cigarette users, vaping flavour and nicotine-less e-cigarettes did not significantly dysregulate cytokine and inflammasome activation [ 43 ].

In addition to its toxicological effects on foetus development, nicotine can disrupt brain development in adolescents and young adults [ 44 , 45 , 46 ]. Several studies have also suggested that nicotine is potentially carcinogenic (reviewed in [ 41 ]), but more work is needed to prove its carcinogenicity independently of the combustion products of tobacco [ 47 ]. In this latter regard, no differences were encountered in the frequency of tumour appearance in rats subjected to long-term (2 years) inhalation of nicotine when compared with control rats [ 48 ]. Despite the lack of carcinogenicity evidence, it has been reported that nicotine promotes tumour cell survival by decreasing apoptosis and increasing proliferation [ 49 ], indicating that it may work as a “tumour enhancer”. In a very recent study, chronic administration of nicotine to mice (1 mg/kg every 3 days for a 60-day period) enhanced brain metastasis by skewing the polarity of M2 microglia, which increases metastatic tumour growth [ 50 ]. Assuming that a conventional cigarette contains 0.172–1.702 mg of nicotine [ 51 ], the daily nicotine dose administered to these animals corresponds to 40–400 cigarettes for a 70 kg-adult, which is a dose of an extremely heavy smoker. We would argue that further studies with chronic administration of low doses of nicotine are required to clearly evaluate its impact on carcinogenicity.

In the aforementioned study exposing human gingival fibroblasts to CS condensate or to nicotine-rich or nicotine-free e-vapour condensates [ 29 ], the detrimental effects were greater in cells exposed to nicotine-rich condensate than to nicotine-free condensate, suggesting that the possible injurious effects of nicotine should be considered when purchasing e-refills . It is also noteworthy that among the 3 most cytotoxic vapours for HUVEC evaluated in the Putzhammer et al . study, 2 were nicotine-free, which suggests that nicotine is not the only hazardous component in e-cigarettes [ 24 ] .

The lethal dose of nicotine for an adult is estimated at 30–60 mg [ 52 ]. Given that nicotine easily diffuses from the dermis to the bloodstream, acute nicotine exposure by e-liquid spilling (5 mL of a 20 mg/mL nicotine-containing refill is equivalent to 100 mg of nicotine) can easily be toxic or even deadly [ 8 ]. Thus, devices with rechargeable refills are another issue of concern with e-cigarettes , especially when e-liquids are not sold in child-safe containers, increasing the risk of spilling, swallowing or breathing.

These data overall indicate that the harmful effects of nicotine should not be underestimated. Despite the established regulations, some inaccuracies in nicotine content labelling remain in different brands of e-liquids . Consequently, stricter regulation and a higher quality control in the e-liquid industry are required.

Effect of humectants and their heating-related products

In this particular aspect, again the composition of the e-liquid varies significantly among different commercial brands [ 4 , 35 ]. The most common and major components of e-liquids are PG or 1,2-propanediol, and glycerol or glycerine (propane-1,2,3-triol). Both types of compounds are used as humectants to prevent the e-liquid from drying out [ 2 , 53 ] and are classified by the Food and Drug Administration (FDA) as “Generally Recognised as Safe” [ 54 ]. In fact, they are widely used as alimentary and pharmaceutical products [ 2 ]. In an analysis of 54 commercially available e-liquids , PG and glycerol were detected in almost all samples at concentrations ranging from 0.4% to 98% (average 57%) and from 0.3% to 95% (average 37%), respectively [ 35 ].

With regards to toxicity, little is known about the effects of humectants when they are heated and chronically inhaled. Studies have indicated that PG can induce respiratory irritation and increase the probability of asthma development [ 55 , 56 ], and both PG and glycerol from e-cigarettes might reach concentrations sufficiently high to potentially cause irritation of the airways [ 57 ]. Indeed, the latter study established that one e-cigarette puff results in a PG exposure of 430–603 mg/m 3 , which is higher than the levels reported to cause airway irritation (average 309 mg/m 3 ) based on a human study [ 55 ]. The same study established that one e-cigarette puff results in a glycerol exposure of 348–495 mg/m 3 [ 57 ], which is close to the levels reported to cause airway irritation in rats (662 mg/m 3 ) [ 58 ].

Airway epithelial injury induced by acute vaping of PG and glycerol aerosols (50:50 vol/vol), with or without nicotine, has been reported in two randomised clinical trials in young tobacco smokers [ 32 ]. In vitro, aerosols from glycerol only-containing refills showed cytotoxicity in A549 and human embryonic stem cells, even at a low battery output voltage [ 59 ]. PG was also found to affect early neurodevelopment in a zebrafish model [ 60 ]. Another important issue is that, under heating conditions PG can produce acetaldehyde or formaldehyde (119.2 or 143.7 ng/puff at 20 W, respectively, on average), while glycerol can also generate acrolein (53.0, 1000.0 or 5.9 ng/puff at 20 W, respectively, on average), all carbonyls with a well-documented toxicity [ 61 ]. Although, assuming 15 puffs per e-cigarette unit, carbonyls produced by PG or glycerol heating would be below the maximum levels found in a conventional cigarette combustion (Table 2 ) [ 51 , 62 ]. Nevertheless, further studies are required to properly test the deleterious effects of all these compounds at physiological doses resembling those to which individuals are chronically exposed.

Although PG and glycerol are the major components of e-liquids other components have been detected. When the aerosols of 4 commercially available e-liquids chosen from a top 10 list of “ Best E-Cigarettes of 2014” , were analysed by gas chromatography-mass spectrometry (GC–MS) after heating, numerous compounds were detected, with nearly half of them not previously identified [ 4 ], thus suggesting that the heating process per se generates new compounds of unknown consequence. Of note, the analysis identified formaldehyde, acetaldehyde and acrolein [ 4 ], 3 carbonyl compounds with known high toxicity [ 63 , 64 , 65 , 66 , 67 ]. While no information was given regarding formaldehyde and acetaldehyde concentrations, the authors calculated that one puff could result in an acrolein exposure of 0.003–0.015 μg/mL [ 4 ]. Assuming 40 mL per puff and 15 puffs per e-cigarette unit (according to several manufacturers) [ 4 ], each e-cigarette unit would generate approximately 1.8–9 μg of acrolein, which is less than the levels of acrolein emitted by a conventional tobacco cigarette (18.3–98.2 μg) [ 51 ]. However, given that e-cigarette units of vaping are not well established, users may puff intermittently throughout the whole day. Thus, assuming 400 to 500 puffs per cartridge, users could be exposed to up to 300 μg of acrolein.

In a similar study, acrolein was found in 11 of 12 aerosols tested, with a similar content range (approximately 0.07–4.19 μg per e-cigarette unit) [ 68 ]. In the same study, both formaldehyde and acetaldehyde were detected in all of the aerosols tested, with contents of 0.2–5.61 μg and 0.11–1.36 μg, respectively, per e-cigarette unit [ 68 ]. It is important to point out that the levels of these toxic products in e-cigarette aerosols are significantly lower than those found in CS: 9 times lower for formaldehyde, 450 times lower for acetaldehyde and 15 times lower for acrolein (Table 2 ) [ 62 , 68 ].

Other compounds that have been detected in aerosols include acetamide, a potential human carcinogen [ 5 ], and some aldehydes [ 69 ], although their levels were minimal. Interestingly, the existence of harmful concentrations of diethylene glycol, a known cytotoxic agent, in e-liquid aerosols is contentious with some studies detecting its presence [ 4 , 68 , 70 , 71 , 72 ], and others finding low subtoxic concentrations [ 73 , 74 ]. Similar observations were reported for the content ethylene glycol. In this regard, either it was detected at concentrations that did not exceed the authorised limit [ 73 ], or it was absent from the aerosols produced [ 4 , 71 , 72 ]. Only one study revealed its presence at high concentration in a very low number of samples [ 5 ]. Nevertheless, its presence above 1 mg/g is not allowed by the FDA [ 73 ]. Figure  1 lists the main compounds detected in aerosols derived from humectant heating and their potential damaging effects. It would seem that future studies should analyse the possible toxic effects of humectants and related products at concentrations similar to those that e-cigarette vapers are exposed to reach conclusive results.

Impact of flavouring compounds

The range of e-liquid flavours available to consumers is extensive and is used to attract both current smokers and new e-cigarette users, which is a growing public health concern [ 6 ]. In fact, over 5 million middle- and high-school students were current users of e-cigarettes in 2019 [ 75 ], and appealing flavours have been identified as the primary reason for e-cigarette consumption in 81% of young users [ 76 ]. Since 2016, the FDA regulates the flavours used in the e-cigarette market and has recently published an enforcement policy on unauthorised flavours, including fruit and mint flavours, which are more appealing to young users [ 77 ]. However, the long-term effects of all flavour chemicals used by this industry (which are more than 15,000) remain unknown and they are not usually included in the product label [ 78 ]. Furthermore, there is no safety guarantee since they may harbour potential toxic or irritating properties [ 5 ].

With regards to the multitude of available flavours, some have demonstrated cytotoxicity [ 59 , 79 ]. Bahl et al. evaluated the toxicity of 36 different e-liquids and 29 different flavours on human embryonic stem cells, mouse neural stem cells and human pulmonary fibroblasts using a metabolic activity assay. In general, those e-liquids that were bubblegum-, butterscotch- and caramel-flavoured did not show any overt cytotoxicity even at the highest dose tested. By contrast, those e-liquids with Freedom Smoke Menthol Arctic and Global Smoke Caramel flavours had marked cytotoxic effects on pulmonary fibroblasts and those with Cinnamon Ceylon flavour were the most cytotoxic in all cell lines [ 79 ]. A further study from the same group [ 80 ] revealed that high cytotoxicity is a recurrent feature of cinnamon-flavoured e-liquids. In this line, results from GC–MS and HPLC analyses indicated that cinnamaldehyde (CAD) and 2-methoxycinnamaldehyde, but not dipropylene glycol or vanillin, were mainly responsible for the high cytotoxicity of cinnamon-flavoured e-liquids [ 80 ]. Other flavouring-related compounds that are associated with respiratory complications [ 81 , 82 , 83 ], such as diacetyl, 2,3-pentanedione or acetoin, were found in 47 out of 51 aerosols of flavoured e-liquids tested [ 84 ] . Allen et al . calculated an average of 239 μg of diacetyl per cartridge [ 84 ]. Assuming again 400 puffs per cartridge and 40 mL per puff, is it is possible to estimate an average of 0.015 ppm of diacetyl per puff, which could compromise normal lung function in the long-term [ 85 ].

The cytotoxic and pro-inflammatory effects of different e-cigarette flavouring chemicals were also tested on two human monocytic cell lines—mono mac 6 (MM6) and U937 [ 86 ]. Among the flavouring chemicals tested, CAD was found to be the most toxic and O-vanillin and pentanedione also showed significant cytotoxicity; by contrast, acetoin, diacetyl, maltol, and coumarin did not show any toxicity at the concentrations assayed (10–1000 µM). Of interest, a higher toxicity was evident when combinations of different flavours or mixed equal proportions of e-liquids from 10 differently flavoured e-liquids were tested, suggesting that vaping a single flavour is less toxic than inhaling mixed flavours [ 86 ]. Also, all the tested flavours produced significant levels of ROS in a cell-free ROS production assay. Finally, diacetyl, pentanedione, O-vanillin, maltol, coumarin, and CAD induced significant IL-8 secretion from MM6 and U937 monocytes [ 86 ]. It should be borne in mind, however, that the concentrations assayed were in the supra-physiological range and it is likely that, once inhaled, these concentrations are not reached in the airway space. Indeed, one of the limitations of the study was that human cells are not exposed to e-liquids per se, but rather to the aerosols where the concentrations are lower [ 86 ]. In this line, the maximum concentration tested (1000 µM) would correspond to approximately 80 to 150 ppm, which is far higher than the levels found in aerosols of some of these compounds [ 84 ]. Moreover, on a day-to-day basis, lungs of e-cigarette users are not constantly exposed to these chemicals for 24 h at these concentrations. Similar limitations were found when five of seven flavourings were found to cause cytotoxicity in human bronchial epithelial cells [ 87 ].

Recently, a commonly commercialized crème brûlée -flavoured aerosol was found to contain high concentrations of benzoic acid (86.9 μg/puff), a well-established respiratory irritant [ 88 ]. When human lung epithelial cells (BEAS-2B and H292) were exposed to this aerosol for 1 h, a marked cytotoxicity was observed in BEAS-2B but not in H292 cells, 24 h later. However, increased ROS production was registered in H292 cells [ 88 ].

Therefore, to fully understand the effects of these compounds, it is relevant the cell cultures selected for performing these assays, as well as the use of in vivo models that mimic the real-life situation of chronic e-cigarette vapers to clarify their impact on human health.

The e-cigarette device

While the bulk of studies related to the impact of e-cigarette use on human health has focused on the e-liquid components and the resulting aerosols produced after heating, a few studies have addressed the material of the electronic device and its potential consequences—specifically, the potential presence of metals such as copper, nickel or silver particles in e-liquids and aerosols originating from the filaments and wires and the atomiser [ 89 , 90 , 91 ].

Other important components in the aerosols include silicate particles from the fiberglass wicks or silicone [ 89 , 90 , 91 ]. Many of these products are known to cause abnormalities in respiratory function and respiratory diseases [ 89 , 90 , 91 ], but more in-depth studies are required. Interestingly, the battery output voltage also seems to have an impact on the cytotoxicity of the aerosol vapours, with e-liquids from a higher battery output voltage showing more toxicity to A549 cells [ 30 ].

A recent study compared the acute effects of e-cigarette vapor (with PG/vegetable glycerine plus tobacco flavouring but without nicotine) generated from stainless‐steel atomizer (SS) heating element or from a nickel‐chromium alloy (NC) [ 92 ]. Some rats received a single e-cigarette exposure for 2 h from a NC heating element (60 or 70 W); other rats received a similar exposure of e-cigarette vapor using a SS heating element for the same period of time (60 or 70 W) and, a final group of animals were exposed for 2 h to air. Neither the air‐exposed rats nor those exposed to e-cigarette vapor using SS heating elements developed respiratory distress. In contrast, 80% of the rats exposed to e-cigarette vapor using NC heating units developed clinical acute respiratory distress when a 70‐W power setting was employed. Thus, suggesting that operating units at higher than recommended settings can cause adverse effects. Nevertheless, there is no doubt that the deleterious effects of battery output voltage are not comparable to those exerted by CS extracts [ 30 ] (Figs.  1 and 2 ).

E-cigarettes as a smoking cessation tool

CS contains a large number of substances—about 7000 different constituents in total, with sizes ranging from atoms to particulate matter, and with many hundreds likely responsible for the harmful effects of this habit [ 93 ]. Given that tobacco is being substituted in great part by e-cigarettes with different chemical compositions, manufacturers claim that e -cigarette will not cause lung diseases such as lung cancer, chronic obstructive pulmonary disease, or cardiovascular disorders often associated with conventional cigarette consumption [ 3 , 94 ]. However, the World Health Organisation suggests that e-cigarettes cannot be considered as a viable method to quit smoking, due to a lack of evidence [ 7 , 95 ]. Indeed, the results of studies addressing the use of e-cigarettes as a smoking cessation tool remain controversial [ 96 , 97 , 98 , 99 , 100 ]. Moreover, both FDA and CDC are actively investigating the incidence of severe respiratory symptoms associated with the use of vaping products [ 77 ]. Because many e-liquids contain nicotine, which is well known for its powerful addictive properties [ 41 ], e-cigarette users can easily switch to conventional cigarette smoking, avoiding smoking cessation. Nevertheless, the possibility of vaping nicotine-free e-cigarettes has led to the branding of these devices as smoking cessation tools [ 2 , 6 , 7 ].

In a recently published randomised trial of 886 subjects who were willing to quit smoking [ 100 ], the abstinence rate was found to be twice as high in the e-cigarette group than in the nicotine-replacement group (18.0% vs. 9.9%) after 1 year. Of note, the abstinence rate found in the nicotine-replacement group was lower than what is usually expected with this therapy. Nevertheless, the incidence of throat and mouth irritation was higher in the e-cigarette group than in the nicotine-replacement group (65.3% vs. 51.2%, respectively). Also, the participant adherence to the treatment after 1-year abstinence was significantly higher in the e-cigarette group (80%) than in nicotine-replacement products group (9%) [ 100 ].

On the other hand, it is estimated that COPD could become the third leading cause of death in 2030 [ 101 ]. Given that COPD is generally associated with smoking habits (approximately 15 to 20% of smokers develop COPD) [ 101 ], smoking cessation is imperative among COPD smokers. Published data revealed a clear reduction of conventional cigarette consumption in COPD smokers that switched to e-cigarettes [ 101 ]. Indeed, a significant reduction in exacerbations was observed and, consequently, the ability to perform physical activities was improved when data was compared with those non-vapers COPD smokers. Nevertheless, a longer follow-up of these COPD patients is required to find out whether they have quitted conventional smoking or even vaping, since the final goal under these circumstances is to quit both habits.

Based on the current literature, it seems that several factors have led to the success of e-cigarette use as a smoking cessation tool. First, some e-cigarette flavours positively affect smoking cessation outcomes among smokers [ 102 ]. Second, e-cigarettes have been described to improve smoking cessation rate only among highly-dependent smokers and not among conventional smokers, suggesting that the individual degree of nicotine dependence plays an important role in this process [ 97 ]. Third, the general belief of their relative harmfulness to consumers' health compared with conventional combustible tobacco [ 103 ]. And finally, the exposure to point-of-sale marketing of e-cigarette has also been identified to affect the smoking cessation success [ 96 ].

Implication of e-cigarette consumption in COVID-19 time

Different reports have pointed out that smokers and vapers are more vulnerable to SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) infections or more prone to adverse outcomes if they suffer COVID-19 [ 104 ]. However, while a systematic review indicated that cigarette smoking is probably associated with enhanced damage from COVID-19, a meta-analysis did not, yet the latter had several limitations due to the small sample sizes [ 105 ].

Interestingly, most of these reports linking COVID-19 harmful effects with smoking or vaping, are based on their capability of increasing the expression of angiotensin-converting enzyme 2 (ACE2) in the lung. It is well known that ACE2 is the gate for SARS-CoV-2 entrance to the airways [ 106 ] and it is mainly expressed in type 2 alveolar epithelial cells and alveolar macrophages [ 107 ]. To date, most of the studies in this field indicate that current smokers have higher expression of ACE2 in the airways (reviewed by [ 108 ]) than healthy non-smokers [ 109 , 110 ]. However, while a recent report indicated that e-cigarette vaping also caused nicotine-dependent ACE2 up-regulation [ 42 ], others have revealed that neither acute inhalation of e-cigarette vapour nor e-cigarette users had increased lung ACE2 expression regardless nicotine presence in the e-liquid [ 43 , 110 ].

In regard to these contentions, current knowledge suggests that increased ACE2 expression is not necessarily linked to enhanced susceptibility to SARS-CoV-2 infection and adverse outcome. Indeed, elderly population express lower levels of ACE2 than young people and SARS-CoV-2/ACE2 interaction further decreases ACE2 expression. In fact, most of the deaths provoked by COVID-19 took place in people over 60 years old of age [ 111 ]. Therefore, it is plausible that the increased susceptibility to disease progression and the subsequent fatal outcome in this population is related to poor angiotensin 1-7 (Ang-1-7) generation, the main peptide generated by ACE2, and probably to their inaccessibility to its anti-inflammatory effects. Furthermore, it seems that all the efforts towards increasing ACE2 expression may result in a better resolution of the pneumonic process associated to this pandemic disease.

Nevertheless, additional complications associated to COVID-19 are increased thrombotic events and cytokine storm. In the lungs, e-cigarette consumption has been correlated to toxicity, oxidative stress, and inflammatory response [ 32 , 112 ]. More recently, a study revealed that while the use of nicotine/flavour-containing e-cigarettes led to significant cytokine dysregulation and potential inflammasome activation, none of these effects were detected in non-flavoured and non-nicotine-containing e-cigarettes [ 43 ]. Therefore, taken together these observations, e-cigarette use may still be a potent risk factor for severe COVID-19 development depending on the flavour and nicotine content.

In summary, it seems that either smoking or nicotine vaping may adversely impact on COVID-19 outcome. However, additional follow up studies are required in COVID-19 pandemic to clarify the effect of e-cigarette use on lung and cardiovascular complications derived from SARS-CoV-2 infection.

Conclusions

The harmful effects of CS and their deleterious consequences are both well recognised and widely investigated. However, and based on the studies carried out so far, it seems that e-cigarette consumption is less toxic than tobacco smoking. This does not necessarily mean, however, that e-cigarettes are free from hazardous effects. Indeed, studies investigating their long-term effects on human health are urgently required. In this regard, the main additional studies needed in this field are summarized in Table 3 .

The composition of e-liquids requires stricter regulation, as they can be easily bought online and many incidences of mislabelling have been detected, which can seriously affect consumers’ health. Beyond their unknown long-term effects on human health, the extended list of appealing flavours available seems to attract new “never-smokers”, which is especially worrying among young users. Additionally, there is still a lack of evidence of e-cigarette consumption as a smoking cessation method. Indeed, e-cigarettes containing nicotine may relieve the craving for smoking, but not the conventional cigarette smoking habit.

Interestingly, there is a strong difference of opinion on e-cigarettes between countries. Whereas countries such as Brazil, Uruguay and India have banned the sale of e-cigarettes , others such as the United Kingdom support this device to quit smoking. The increasing number of adolescent users and reported deaths in the United States prompted the government to ban the sale of flavoured e-cigarettes in 2020. The difference in opinion worldwide may be due to different restrictions imposed. For example, while no more than 20 ng/mL of nicotine is allowed in the EU, e-liquids with 59 mg/dL are currently available in the United States. Nevertheless, despite the national restrictions, users can easily access foreign or even counterfeit products online.

In regard to COVID-19 pandemic, the actual literature suggests that nicotine vaping may display adverse outcomes. Therefore, follow up studies are necessary to clarify the impact of e-cigarette consumption on human health in SARS-CoV-2 infection.

In conclusion, e-cigarettes could be a good alternative to conventional tobacco cigarettes, with less side effects; however, a stricter sale control, a proper regulation of the industry including flavour restriction, as well as further toxicological studies, including their chronic effects, are warranted.

Availability of data and materials

Not applicable.

Abbreviations

Angiotensin-converting enzyme 2

Angiotensin 1-7

Bronchoalveolar lavage fluid

Cinnamaldehyde

US Centers for Disease Control and Prevention

Carbon monoxide

Chronic obstructive pulmonary disease

Coronavirus disease 2019

Cigarette smoke

Electronic nicotine dispensing systems

e-cigarette or vaping product use-associated lung injury

Food and Drug Administration

Gas chromatography with a flame ionisation detector

Gas chromatography-mass spectrometry

Granulocyte–macrophage colony-stimulating factor

High performance liquid chromatography

Human umbilical vein endothelial cells

Interleukin

Interferon γ

Liquid chromatography-mass spectrometry

Monocyte chemoattractant protein-1

Matrix metallopeptidase 9

α7 Nicotinic acetylcholine receptor

Nickel‐chromium alloy

Nitric oxide

Propylene glycol

Regulated on activation, normal T cell expressed and secreted

Reactive oxygen species

Severe acute respiratory syndrome coronavirus 2

Stainless‐steel atomizer

Tetrahydrocannabinol

Tumour necrosis factor-α

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Acknowledgements

The authors gratefully acknowledge Dr. Cruz González, Pulmonologist at University Clinic Hospital of Valencia (Valencia, Spain) for her thoughtful suggestions and support.

This work was supported by the Spanish Ministry of Science and Innovation [Grant Number SAF2017-89714-R]; Carlos III Health Institute [Grant Numbers PIE15/00013, PI18/00209]; Generalitat Valenciana [Grant Number PROMETEO/2019/032, Gent T CDEI-04/20-A and AICO/2019/250], and the European Regional Development Fund.

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Patrice Marques, Laura Piqueras & Maria-Jesus Sanz

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Marques, P., Piqueras, L. & Sanz, MJ. An updated overview of e-cigarette impact on human health. Respir Res 22 , 151 (2021). https://doi.org/10.1186/s12931-021-01737-5

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Why e-cigarettes are better for smokers than regular ones essay sample, example.

Smoking tobacco is probably one of the worst habits humankind has developed. Originating as a tradition of the Native Americans, practiced mostly on special occasions, smoking has gradually become a kind of mass addiction. Due to the efforts of tobacco companies seeking to increase their sales, people started smoking more and more often; the evolution of a more traditional pipe to a cigarette took some time, but eventually tobacco became more affordable and easier to use (you now simply need to light it up, instead of having to always carry a tobacco pouch, stuff a pipe, puff it, and so on). As a result, deaths and health issues connected to tobacco consumption became a worldwide concern.

A popular belief is that it is nicotine that kills. It is only partially true: although nicotine does harm one’s health (mostly affecting the cardiovascular system), it is the tar, carbon monoxide, hard particles contained in cigarette smoke, and a bunch of toxic emissions and heavy metals that deal the most damage. Nicotine causes addiction, and the smoke does the rest.

Nowadays, there are alternatives to analogue tobacco smoking: the widely popular electronic cigarettes. Although it is hotly debated whether e-cigarettes are harmful to smokers’ health or not, it is hard to argue that substituting cigarettes with these devices does more good than bad, since they possess a number of advantages that cannot be neglected easily. And whereas smoking still remains a dangerous and unacceptable addiction, e-cigarettes might be a decent way to break free of it.

Electronic cigarettes deliver nicotine to a smoker not through burning (which obviously implies inhaling harmful and toxic smoke), but through the evaporation of nicotine-containing liquids. An e-cigarette heats up the liquid in a special container called an atomizer; the liquid evaporates, and through this vapor a smoker receives their dose of nicotine. Thus, the process of nicotine consumption in this case should be called “vaping,” not “smoking.” These liquids usually comprise glycerol, propylene glycol, ethylene glycol, propanediol, and some other components ( NCBI ). Although some of them are not completely harmless, the chemical composure of e-cigarette liquids is definitely safer than the one of a regular cigarette. However, thorough control over the composure of these liquids should be established, and the usage of such components as ethylene glycol and propanediol should probably be banned. Still, if a smoker does not plan to quit, he or she might want to consider using e-cigarettes instead of real tobacco.

Another good reason for a smoker to start using e-cigarettes is that the aforementioned liquids can contain different amounts of nicotine. A heavy smoker might want to start vaping using liquids containing up to 24 milligrams of nicotine, and the good news for them is that it is possible to gradually decrease the dose until zero milligrams are present.

Although some smokers might experience physical symptoms when trying to quit smoking tobacco, in the majority of cases, it is a strong psychological component that does not let a smoker give up their addiction. It can be assumed that there are five main components of this psychological addiction: 1) believing in the relaxing/stimulating effect of nicotine that helps a smoker deal with stressful situations; 2) a smoker’s need to “keep hands busy” when bored, waiting for something, feeling nervous, and so on; 3) socializing with “fellow smokers”; 4) unconsciously and “automatically” following the habit; 5) the fear that if a smoker quits, he or she will lose something valuable, a source of psychological support or pleasure. In addition, some smokers find it aesthetic to inhale/exhale smoke, or have other reasons to continue tobacco consumption. Generally speaking, smoking is a behavioral pattern consisting of repeating situations and reactions. Without neglecting or challenging these reasons, it can be said that an e-cigarette is probably a safer alternative for a person who does not want to give up nicotine. They still deliver nicotine to a smoker’s body (thus fulfilling the reasons 1 and 5); they disrupt automatic smoking described in points 2 and 4 (since e-cigarettes function differently from their traditional analogues); they allow a person to continue socializing with other smokers during breaks at work, or on other occasions, as mentioned in point 3. But, while performing the same functions as regular cigarettes, electronic devices are safer and more socially acceptable.

In addition, a purely aesthetic reason to prefer e-cigarettes over their analogues: when evaporated, the liquids taste and smell better than tobacco. They are sold in a variety of flavors: melons, apples, cherry, tropical fruit, mint, blueberry, and so on. At the same time, regular tobacco smells and tastes awful not only for the non-smokers, but for a smoking person as well. So, why not stop poisoning oneself with toxic smoke, and at least substitute it with pleasantly smelling vapor?

Nicotine addiction in any of its forms, regardless of whether it is smoking or vaping, is a huge problem for addicts. It leads to a number of severe, chronic diseases and even to death. At the same time, there might be a healthier alternative for those smokers who realize the harm they cause to themselves, but who cannot yet give up their addiction. Electronic cigarettes are nowadays considered to be safer than regular cigarettes. Liquids used in these e-cigarettes contain fewer toxic elements, and do not include the products that are commonly burned in cigarettes. Vapor from e-cigarettes is mostly harmless to non-smokers; it tastes and smells better, which makes smoking e-cigarettes a less reproached habit. Finally, many smokers might discover that e-cigarettes do not obstruct their reasons to continue smoking, while making it possible to decrease the amounts of consumed nicotine and to eventually break the habit. Therefore, without praising or advertising e-cigarettes, it can still be stated that they are a more preferable alternative for smokers.

Works Cited

• “Electronic Cigarettes: Overview of Chemical Composition and Exposure Estimation.” NCBI . BioMed Central, 2014. Web. 14 Nov. 2016.

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Electronic cigarettes, otherwise known as e-cigarettes, are battery-operated electronic smoking devices that differ from traditional cigarettes because they emit an aerosol vapor instead of smoke, and typically consists of various flavorings of fruits and candy, nicotine, propylene glycol, and other chemicals. They are manufactured to resemble either traditional cigarettes, cigars or pipes, pens, or even USB memory drives. Since its initial introduction in the United States in 2007, the trend of adolescents who use e-cigarettes has grown rapidly. Between 2013 and 2014 alone, e-cigarette use has tripled among middle school students (1.1%-3.9%) and high school students (4.5%-13.4%) making e-cigarettes the most commonly used nicotine product among adolescents. This is a public health concern because research suggests that adolescents who use e-cigarettes are likely to experiment with other tobacco products in the future, such as conventional cigarettes, putting them at risk of several associated diseases. Several factors contribute to the alarming rates of e-cigarette use among teens, which includes concentrated amounts of tobacco retail stores in their environments, as well as advertisements displayed on TV, billboards, print media, the internet, and through point of sales (POS) displays of tobacco products. Adolescents who have never smoked but recall tobacco POS are more likely to become smokers after 30 months of follow-up. The opposite effect is true when tobacco POS is banned, as seen in other parts of the world, as well as when increased taxes on cigarettes are imposed. Consequently, increased availability and advertising of e-cigarettes is associated with its higher consumption among youth. Although research is limited to the exact health effects associated with e-cigarette use, it can likely cause secondhand exposure, despite the fact that emittance of nicotine and probable carcinogens are released at lower rates than traditional cigarettes. Also, accidental overdose and poisoning of nicotine liquids are likely among youth, due to the fact that the solution is sold in bottles and cartridges. There is contradicting evidence to support the claims made by e-cigarette manufacturers that e-cigarettes are a healthier alternative to traditional cigarette products and are useful as a smoking cessation tool, especially due to the fact that it contains nicotine and other harmful substances as well. Studies have proven that exposure to nicotine during adolescence has several harmful effects on brain development such as attention and cognition deficits, mood dysfunctions, and increased propensity for negative risk taking. Nonetheless, very little is known about the product in general and thus, it is difficult to determine its health risks and if it differentiates at all from regular cigarettes. Adolescents are increasingly exposed to e-cigarette advertisements primarily because there are no regulations on them. Since April 2014, the FDA only proposes to regulate e-cigarettes that are marketed for its therapeutic use, for instance, to aid in the cessation of smoking. However, there is currently no e-cigarette that is approved by the FDA according to this standard. Lack of regulation has allowed the e-cigarette industry to launch marketing campaigns that appeal particularly to adolescents, which contributes to their increased use and inception of use among those who have never smoked. Advertisements for e-cigarettes have been broadcasted on many popular television programs such as during the 2013 Super Bowl commercials by the e-cigarette company NJOY and are frequently advertised on popular social media websites like Facebook and YouTube. Even popular cartoon characters like “Hello Kitty” have been used in advertisements of e-cigarettes. Overall, due to the propensity of e-cigarette companies to market their products that are appealing towards youth, their subsequent surge of use, as well as the potential health risks that are associated with it, there is a need for regulation of e-cigarette products that involve banning or restricting its promotion, advertisement, and sponsorship.

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Home — Essay Samples — Social Issues — Vaping — Electronic Cigarettes and Vape Products Should Be Banned

Electronic Cigarettes and Vape Products Should Be Banned

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Expertly Written Argumentative Essay On Smoking E-Cigarettes To Follow

Type of paper: Argumentative Essay

Topic: Smoking , Teenagers , Cigarettes , Health , Students , Teen , Teens , Cigarette

Published: 03/08/2023

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[Health care]

Introduction

Though smoking has only negative effects, especially when it can cause different cancers in the body, nevertheless, the mass media try to make smoking look acceptable and cool, which helps tobacco firms enlarge their revenues (Services, Health and First).

In recent years, separated from traditional cigarette smoking, which comparatively went down, we can observe a significant increase in using electronic cigarettes. The amount of students who are studying in high school or even middle school, continue smoking e-cigarettes and what is terrible to state that the number of such occasions doubled from 2012 and kept increasing (Gonchar). Teenagers think that it is cool to smoke e-cigarette, however, they do not care about health problems that may occur in the elderly. Entirely in 2012 year, up to 1.8 million both high and middle school students in total told that they had already tried e-cigarettes, which anyway cannot be good, according to the national survey, carried out by the Centers for Disease Control and Prevention ("Notes From The Field: Electronic Cigarette Use Among Middle And High School Students — United States"). Moreover, respondents said that they had tried single cigarettes before. Despite the fact that traditional cigarette smoking in high and middle schools has declined to record lows, the use of e-cigarettes tripled from 2013 to 2014 (Steinmetz).

Some facts about smoking

Here is some valid data about smoking: 90% of all smokers began this activity before 19 years old; approximately 30% of all teenagers will keep on smoking and die early because of a smoking-related illness; youngsters smokers are more inclined to get panic attacks, have mental health problems, nervous disorders or suffer from depression; researchers found that very first cigarette to be smoked by a teenager usually occurs before the graduation from the high school; commonly smokers live 13-14 years less than non-smokers; annually up to 1.5 million packs are bought by minors; some investigations proved that hookah smoke has a higher level of a combination of tar, nicotine or heavy metals, rather than smoke of typical cigarettes ("11 Facts About Teen Smoking”).

Health risks

Smoking tobacco is very harmful to your health in the short and long haul. In a short period of time, it can cause serious difficulties to your breath and can result in diminished lung function. Moreover, it can lead to respiratory diseases and coughing. In addition, smoking can decrease physical activity of a teenager engaged in some sports or gym. Long haul smoking can be very fatal to your health: it may cause serious health issues, constant lung troubles, heart attacks or even problems with vision (Boehlke).

Addiction to tobacco use

People became addicted to smoking because of nicotine concentration in tobacco. Here are several symptoms of addiction: you feel anxious without a cigarette; you want to smoke and cannot even wait a minute without a puff; one day you decided to abandon smoking but later continue doing that, etc. What should be added here, that other forms of tobacco, such as e-cigarettes, chewing tobacco, menthol cigarettes or cigars are threatening to your health as well, because they accommodate deadly chemicals/ingredients that can damage your feeling ("For Teens: Straight Talk About Smoking").

On the whole, smoking is not only a problem for teenagers, but also a threat to their health. Parents should control their kids, explain how serious this issue is, and tell them that the longer children wait to stop smoking the harder it will be for them to quit. Is quitting possible? Yes, certainly, there is always a way out! However, not for everybody it is that easy to stop smoking. Just give it a try and that is all! Even you fail to quit smoking, do your best to make the second attempt. Practice make excellent!

Works cited

Services, A, 1st Health, and Recovery First. "Teens And Smoking – Nicotine Addiction – Teen Smoking – Problems With Teen Smoking". Projectknow.com. N.p., 2016. Web. 14 May 2016. Retrieved from: http://www.projectknow.com/research/teens-and-smoking/ Gonchar, Michael. "Is Smoking Still A Problem Among Teenagers?". The Learning Network. N.p., 2013. Web. 14 May 2016. Retrieved from: http://learning.blogs.nytimes.com/2013/09/06/is-smoking-still-a-problem-among-teenagers/?_r=0 "Notes From The Field: Electronic Cigarette Use Among Middle And High School Students — United States, 2011–2012". Cdc.gov. N.p., 2016. Web. 14 May 2016. Retrieved from: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6235a6.htm?s_cid=mm6235a6_w "11 Facts About Teen Smoking | Dosomething.Org | Volunteer For Social Change". Dosomething.org. N.p., 2016. Web. 14 May 2016. Retrieved from: https://www.dosomething.org/facts/11-facts-about-teen-smoking Boehlke, Julie. "Teen Smoking Problems". LIVESTRONG.COM. N.p., 2015. Web. 14 May 2016. Retrieved from: http://www.livestrong.com/article/108848-teen-smoking-problems/ "For Teens: Straight Talk About Smoking". HealthyChildren.org. N.p., 2016. Web. 14 May 2016. Retrieved from: https://www.healthychildren.org/English/ages-stages/teen/substance-abuse/Pages/Teens-and-Smoking.aspx Steinmetz, Krystal. "Smoking Is Down Among Teens, But There’S This Other Problem ". Money Talks News. N.p., 2015. Web. 14 May 2016. Retrieved from: http://www.moneytalksnews.com/smoking-down-among-teens-but-theres-this-other-problem/

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