The Wild West of E-Cigarettes
- Silvia Balbo*Silvia Balbo*E-mail: [email protected]Masonic Cancer Center, University of Minnesota, 2231 Sixth St. SE, Minneapolis, Minnesota 55455, United StatesMore by Silvia Balbo
- and
- Irina StepanovIrina StepanovMasonic Cancer Center, University of Minnesota, 2231 Sixth St. SE, Minneapolis, Minnesota 55455, United StatesMore by Irina Stepanov
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Abstract
The popularity of e-cigarettes is growing exponentially. Yet, the health risks associated with their use remain unclear, mainly due to the fact that they are not “one product”, but a combination of ever-evolving designs, flavors, brands, and modes of use. Research needs to better understand how these variables affect toxicity.
This publication is licensed for personal use by The American Chemical Society.
Electronic cigarettes, or e-cigarettes, are battery-powered devices designed to deliver nicotine without combusting tobacco. These devices generate aerosol by heating liquid (e-liquid) that typically contains nicotine dissolved in a mixture of propylene glycol or vegetable glycerin, with the optional presence of flavorings. There has been an exponential growth in popularity of e-cigarettes over the past decade. (1,2) This adoption has been accompanied by a significant amount of research to understand the chemical composition of e-cigarette aerosols, the impact of these devices on health risks, their abuse liability, and their potential to aid in smoking cessation. Despite substantial e-cigarette data accumulated over recent years, the only general consensus is that e-cigarette aerosol contains much lower levels of many toxicants and carcinogens that are abundant in cigarette smoke. There is still a critical lack of progress in other key areas of e-cigarette research.
There are several reasons why the gaps in our current understanding represent an urgent public health issue. First, e-cigarettes are particularly popular among the youth: according to a 2016 report by the U.S. Surgeon General, 13.5% of middle school students, 37.7% of high school students, and 35.8% of young adults (18–24 years of age) have used e-cigarettes, compared with 16.4% of adults (25 years and older). In addition, there is an urgent need to understand the relative impact of switching to e-cigarette use on smokers with health conditions caused or exacerbated by smoking, such as respiratory and cardiovascular diseases or cancer. Lastly, any regulatory measures by the World Health Organization, United States Food and Drug Administration, and other agencies need to be based on conclusive scientific evidence in order to minimize harm and protect public health.
So, why is it so difficult to produce clear and reproducible scientific data on e-cigarettes, a product that appears relatively simple? One of the major reasons is that it is not “one product”, but rather a Wild West of ever-evolving designs, flavors, brands, and modes of use, just to mention a few of many variables. These devices first appeared on the market as models resembling conventional cigarettes in shape and size, commonly referred to as “cig-a-like” type. The next generation of e-cigarettes, commonly referred to as “vape pens” or “eGos”, came in a larger size and featured a removable “tank” that can be refilled with nicotine-containing e-liquid. And the following generation of such tank systems, referred to as “mods”, became even larger and offered a plethora of customizable voltages and other settings. (3) The most recent addition which has gained great popularity, especially among high school students is JUUL, an electronic nicotine delivery device that looks like an USB drive. All of these generations, or categories, of e-cigarettes currently co-exist on the market in a vast variety of brands. The heating process of e-cigarette liquid and the aerosol yield and characteristics are highly dependent on the design of the device, the energy delivered from the battery, the airflow rate required to produce aerosol, the pressure drop, and the length of time the cartridges last, with all these characteristics often varying between and within brands. (4) Adding to this complexity is the enormous variety of e-liquids. As of January 2014, a study reported that the total number of unique flavors for 466 existing brands was 7764. (3) Nicotine content of e-liquids is usually reported in different ways, using milligrams, percentages, or descriptors like low, medium, and high, and the value indicated on the label does not always match the actual nicotine content. The number of brands, the variability in the device performance, the variety of flavors and composition of the e-liquids, the variation in amount of nicotine in each product, in addition to the possibility for consumers to customize their own liquids adding constituents, like alcohol, tobacco, and marijuana, creates significant barriers in cross-referencing results of various in vitro, in vivo, and human studies and critically limits the generalizability of any individual study. Furthermore, studies have shown large individual differences in nicotine levels in subjects using the same product, adding one more source of variability. Another important factor is that the impact of e-cigarettes occurs in the context of the widespread and continuing availability of conventional cigarettes and other tobacco products, resulting in high levels of dual use of e-cigarettes and conventional cigarettes. In smokers, e-cigarette uptake and subsequent changes in exposures and effects may be influenced by the “learning curve” for e-cigarette use. Unlike regular cigarettes, these devices have more components that need to be activated, and therefore new users must learn how to operate them to achieve consistent and satisfying nicotine intake experience. However, many of the currently published studies were conducted in e-cigarette-naive subjects, which may have affected study results. Finally, marketing and other environmental influences vary from country to country, influencing use patterns and the ultimate impact on public health differing depending on the geographical area the studies focus on.
There is an urgent and critical role for chemical toxicology research in the e-cigarette field. Such research is needed to better understand how the composition of e-liquids and the design of the devices affect toxicity. Studies are consistent in showing that e-cigarette aerosols contain some key tobacco-related constituents at levels significantly lower than in cigarette smoke. (5) However, emerging evidence suggests that the chemical profile of e-cigarette aerosols is distinct from cigarette smoke and that some byproducts of e-liquid decomposition may induce inflammatory processes and present a toxic and/or carcinogenic risk. For instance, the exposure of cultured cells to e-cigarette liquid or aerosols has been shown to reduce cell viability, induce cytokine production, and cause oxidative stress. Similarly, inflammatory responses in the lungs and DNA damage in various organs have been observed when exposing animals (mice and rats) to e-cigarette aerosols. A recent study has also shown that the potent oral and esophageal carcinogen N′-nitrosonornicotine (NNN) can be formed engodenously in e-cigarette users. Furthermore, while most of the ingredients in e-liquids, including many of the flavorings, are approved for human consumption, their safety has mainly been assessed for ingestion. In e-cigarettes, the liquid is subject to heating and evaporation, resulting in the emission of an aerosol that is inhaled instead of ingested. Direct lung exposure may result in fast absorption directly into arterial circulation and bypass of liver metabolism. The safety of many of e-liquid ingredients via inhalation remains to be established. Such knowledge is important for establishing product standards including criteria for ingredients, quality, and manufacturing. There is also an urgent need to develop testing tools and models to meet the future challenges from yet new versions of electronic nicotine delivery devices.
It is important to remember that e-cigarettes are not just one product. It is important to think creatively about designing studies that can be cross-referenced with other research findings and extrapolated to other products. Examples include using more than one product in each study, using reference products (e.g., Standardized Research E-Cigarette, or SREC, developed by the U.S. National Institute for Drug Abuse), incorporating the characterization of the e-liquid and the aerosol composition in studies, and assessing exposures in users. Such approaches may help to tame the Wild West of e-cigarettes and understand their public health impact.
Author Information
- Silvia Balbo, Masonic Cancer Center, University of Minnesota, 2231 Sixth St. SE, Minneapolis, Minnesota 55455, United States,
http://orcid.org/0000-0002-7686-0504,
- Irina Stepanov, Masonic Cancer Center, University of Minnesota, 2231 Sixth St. SE, Minneapolis, Minnesota 55455, United States,http://orcid.org/0000-0001-5140-8944
References
This article references 5 other publications.
- 1McMillen, R. C., Gottlieb, M. A., Shaefer, R. M. W., Winickoff, J. P., and Klein, J. D. (2015) Trends in Electronic Cigarette Use Among U.S. Adults: Use is Increasing in Both Smokers and Nonsmokers. Nicotine Tob. Res. 17, 1195– 1202, DOI: 10.1093/ntr/ntu213Google Scholar1https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2M3mslCmsw%253D%253D&md5=7a4eb413dd2ad0788431c5a068d18403Trends in Electronic Cigarette Use Among U.S. Adults: Use is Increasing in Both Smokers and NonsmokersMcMillen Robert C; Gottlieb Mark A; Shaefer Regina M Whitmore; Klein Jonathan D; Winickoff Jonathan PNicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco (2015), 17 (10), 1195-202 ISSN:.OBJECTIVES: We assessed trends in use of electronic cigarettes among U.S. adults, demographic predictors of use, and smoking status of current electronic cigarette users. METHODS: Mixed-mode surveys were used to obtain representative, cross-sectional samples of U.S. adults in each of 4 years. RESULTS: Sample sizes for 2010, 2011, 2012, and 2013 were 3,240, 3,097, 3,101, and 3,245, respectively. Ever use of electronic cigarettes increased from 1.8% (2010) to 13.0% (2013), while current use increased from 0.3% to 6.8%, p < .001. Prevalence of use increased significantly across all demographic groups. In 2013, current use among young adults 18-24 (14.2%) was higher than adults 25-44 (8.6%), 45-64 (5.5%), and 65+ (1.2%). Daily smokers (30.3%) and nondaily smokers (34.1%) were the most likely to currently use e-cigarettes, compared to former smokers (5.4%) and never-smokers (1.4%), p < .001. However, 32.5% of current electronic cigarette users are never- or former smokers. CONCLUSIONS: There has been rapid growth in ever and current electronic cigarette use over the past 4 years. Use is highest among young adults and current cigarette smokers. Although smokers are most likely to use these products, almost a third of current users are nonsmokers, suggesting that e-cigarettes contribute to primary nicotine addiction and to renormalization of tobacco use. Regulatory action is needed at the federal, state, and local levels to ensure that these products do not contribute to preventable chronic disease.
- 2Singh, T. (2016) Tobacco Use Among Middle and High School Students — United States, 2011–2015. MMWR. Morbidity and Mortality Weekly Report 65, 361– 367, DOI: 10.15585/mmwr.mm6514a1Google Scholar2https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC28bgt1Ggtg%253D%253D&md5=30309e3d3b8e3c76cf7c64d263dc6e89Tobacco Use Among Middle and High School Students--United States, 2011-2015Singh Tushar; Arrazola Rene A; Corey Catherine G; Husten Corinne G; Neff Linda J; Homa David M; King Brian AMMWR. Morbidity and mortality weekly report (2016), 65 (14), 361-7 ISSN:.Tobacco use is the leading cause of preventable disease and death in the United States; if current smoking rates continue, 5.6 million Americans aged <18 years who are alive today are projected to die prematurely from smoking-related disease. Tobacco use and addiction mostly begin during youth and young adulthood. CDC and the Food and Drug Administration (FDA) analyzed data from the 2011-2015 National Youth Tobacco Surveys (NYTS) to determine the prevalence and trends of current (past 30-day) use of seven tobacco product types (cigarettes, cigars, smokeless tobacco, electronic cigarettes [e-cigarettes], hookahs [water pipes used to smoke tobacco], pipe tobacco, and bidis [small imported cigarettes wrapped in a tendu leaf]) among U.S. middle (grades 6-8) and high (grades 9-12) school students. In 2015, e-cigarettes were the most commonly used tobacco product among middle (5.3%) and high (16.0%) school students. During 2011-2015, significant increases in current use of e-cigarettes and hookahs occurred among middle and high school students, whereas current use of conventional tobacco products, such as cigarettes and cigars decreased, resulting in no change in overall tobacco product use. During 2014-2015, current use of e-cigarettes increased among middle school students, whereas current use of hookahs decreased among high school students; in contrast, no change was observed in use of hookahs among middle school students, use of e-cigarettes among high school students, or use of cigarettes, cigars, smokeless tobacco, pipe tobacco, or bidis among middle and high school students. In 2015, an estimated 4.7 million middle and high school students were current tobacco product users, and, therefore, continue to be exposed to harmful tobacco product constituents, including nicotine. Nicotine exposure during adolescence, a critical period for brain development, can cause addiction, might harm brain development, and could lead to sustained tobacco product use among youths. Comprehensive and sustained strategies are warranted to prevent and reduce the use of all tobacco products among U.S. youths.
- 3Zhu, S.-H. (2014) Four hundred and sixty brands of e-cigarettes and counting: implications for product regulation. Tobacco Control 23, iii3– iii9, DOI: 10.1136/tobaccocontrol-2014-051670Google ScholarThere is no corresponding record for this reference.
- 4Williams, M. and Talbot, P. (2011) Variability Among Electronic Cigarettes in the Pressure Drop, Airflow Rate, and Aerosol Production. Nicotine Tob. Res. 13, 1276– 1283, DOI: 10.1093/ntr/ntr164Google Scholar4https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC38%252Fis1CksA%253D%253D&md5=9215b58c84f2d0e73f9d3ec909fa30a6Variability among electronic cigarettes in the pressure drop, airflow rate, and aerosol productionWilliams Monique; Talbot PrueNicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco (2011), 13 (12), 1276-83 ISSN:.INTRODUCTION: This study investigated the performance of electronic cigarettes (e-cigarettes), compared different models within a brand, compared identical copies of the same model within a brand, and examined performance using different protocols. METHODS: Airflow rate required to generate aerosol, pressure drop across e-cigarettes, and aerosol density were examined using three different protocols. RESULTS: First 10 puff protocol: The airflow rate required to produce aerosol and aerosol density varied among brands, while pressure drop varied among brands and between the same model within a brand. Total air hole area correlated with pressure drop for some brands. Smoke-out protocol: E-cigarettes within a brand generally performed similarly when puffed to exhaustion; however, there was considerable variation between brands in pressure drop, airflow rate required to produce aerosol, and the total number of puffs produced. With this protocol, aerosol density varied significantly between puffs and gradually declined. CONSECUTIVE TRIAL PROTOCOL: Two copies of one model were subjected to 11 puffs in three consecutive trials with breaks between trials. One copy performed similarly in each trial, while the second copy of the same model produced little aerosol during the third trial. The different performance properties of the two units were attributed to the atomizers. CONCLUSION: There was significant variability between and within brands in the airflow rate required to produce aerosol, pressure drop, length of time cartridges lasted, and production of aerosol. Variation in performance properties within brands suggests a need for better quality control during e-cigarette manufacture.
- 5Goniewicz, M. L. (2014) Levels of selected carcinogens and toxicants in vapour from electronic cigarettes. Tobacco Control 23, 133– 139, DOI: 10.1136/tobaccocontrol-2012-050859Google Scholar5https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3svjvVGjtw%253D%253D&md5=85173602b1891dbeb7cded6135b3a52cLevels of selected carcinogens and toxicants in vapour from electronic cigarettesGoniewicz Maciej Lukasz; Knysak Jakub; Gawron Michal; Kosmider Leon; Sobczak Andrzej; Kurek Jolanta; Prokopowicz Adam; Jablonska-Czapla Magdalena; Rosik-Dulewska Czeslawa; Havel Christopher; Jacob Peyton 3rd; Benowitz NealTobacco control (2014), 23 (2), 133-9 ISSN:.SIGNIFICANCE: Electronic cigarettes, also known as e-cigarettes, are devices designed to imitate regular cigarettes and deliver nicotine via inhalation without combusting tobacco. They are purported to deliver nicotine without other toxicants and to be a safer alternative to regular cigarettes. However, little toxicity testing has been performed to evaluate the chemical nature of vapour generated from e-cigarettes. The aim of this study was to screen e-cigarette vapours for content of four groups of potentially toxic and carcinogenic compounds: carbonyls, volatile organic compounds, nitrosamines and heavy metals. MATERIALS AND METHODS: Vapours were generated from 12 brands of e-cigarettes and the reference product, the medicinal nicotine inhaler, in controlled conditions using a modified smoking machine. The selected toxic compounds were extracted from vapours into a solid or liquid phase and analysed with chromatographic and spectroscopy methods. RESULTS: We found that the e-cigarette vapours contained some toxic substances. The levels of the toxicants were 9-450 times lower than in cigarette smoke and were, in many cases, comparable with trace amounts found in the reference product. CONCLUSIONS: Our findings are consistent with the idea that substituting tobacco cigarettes with e-cigarettes may substantially reduce exposure to selected tobacco-specific toxicants. E-cigarettes as a harm reduction strategy among smokers unwilling to quit, warrants further study. (To view this abstract in Polish and German, please see the supplementary files online.).
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, 1289-1298. https://doi.org/10.1021/acs.chemrestox.9b00085
- Benjamin Cromwell, Lisa Cid Mota, Mindy Levine. Detection of Potentially Toxic Additives in Electronic Cigarettes and Cigarette Flavourings. Analytical Letters 2020, 53
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, 1407-1415. https://doi.org/10.1080/00032719.2019.1708922
- Alexandra M. Ward, Rola Yaman, Jon O. Ebbert, . Electronic nicotine delivery system design and aerosol toxicants: A systematic review. PLOS ONE 2020, 15
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, e0234189. https://doi.org/10.1371/journal.pone.0234189
- Michael J. Bozzella, Matthew Magyar, Roberta L. DeBiasi, Kathleen Ferrer. Epiglottitis Associated With Intermittent E-cigarette Use: The Vagaries of Vaping Toxicity. Pediatrics 2020, 145
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https://doi.org/10.1542/peds.2019-2399
Abstract
References
ARTICLE SECTIONSThis article references 5 other publications.
- 1McMillen, R. C., Gottlieb, M. A., Shaefer, R. M. W., Winickoff, J. P., and Klein, J. D. (2015) Trends in Electronic Cigarette Use Among U.S. Adults: Use is Increasing in Both Smokers and Nonsmokers. Nicotine Tob. Res. 17, 1195– 1202, DOI: 10.1093/ntr/ntu213Google Scholar1https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2M3mslCmsw%253D%253D&md5=7a4eb413dd2ad0788431c5a068d18403Trends in Electronic Cigarette Use Among U.S. Adults: Use is Increasing in Both Smokers and NonsmokersMcMillen Robert C; Gottlieb Mark A; Shaefer Regina M Whitmore; Klein Jonathan D; Winickoff Jonathan PNicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco (2015), 17 (10), 1195-202 ISSN:.OBJECTIVES: We assessed trends in use of electronic cigarettes among U.S. adults, demographic predictors of use, and smoking status of current electronic cigarette users. METHODS: Mixed-mode surveys were used to obtain representative, cross-sectional samples of U.S. adults in each of 4 years. RESULTS: Sample sizes for 2010, 2011, 2012, and 2013 were 3,240, 3,097, 3,101, and 3,245, respectively. Ever use of electronic cigarettes increased from 1.8% (2010) to 13.0% (2013), while current use increased from 0.3% to 6.8%, p < .001. Prevalence of use increased significantly across all demographic groups. In 2013, current use among young adults 18-24 (14.2%) was higher than adults 25-44 (8.6%), 45-64 (5.5%), and 65+ (1.2%). Daily smokers (30.3%) and nondaily smokers (34.1%) were the most likely to currently use e-cigarettes, compared to former smokers (5.4%) and never-smokers (1.4%), p < .001. However, 32.5% of current electronic cigarette users are never- or former smokers. CONCLUSIONS: There has been rapid growth in ever and current electronic cigarette use over the past 4 years. Use is highest among young adults and current cigarette smokers. Although smokers are most likely to use these products, almost a third of current users are nonsmokers, suggesting that e-cigarettes contribute to primary nicotine addiction and to renormalization of tobacco use. Regulatory action is needed at the federal, state, and local levels to ensure that these products do not contribute to preventable chronic disease.
- 2Singh, T. (2016) Tobacco Use Among Middle and High School Students — United States, 2011–2015. MMWR. Morbidity and Mortality Weekly Report 65, 361– 367, DOI: 10.15585/mmwr.mm6514a1Google Scholar2https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC28bgt1Ggtg%253D%253D&md5=30309e3d3b8e3c76cf7c64d263dc6e89Tobacco Use Among Middle and High School Students--United States, 2011-2015Singh Tushar; Arrazola Rene A; Corey Catherine G; Husten Corinne G; Neff Linda J; Homa David M; King Brian AMMWR. Morbidity and mortality weekly report (2016), 65 (14), 361-7 ISSN:.Tobacco use is the leading cause of preventable disease and death in the United States; if current smoking rates continue, 5.6 million Americans aged <18 years who are alive today are projected to die prematurely from smoking-related disease. Tobacco use and addiction mostly begin during youth and young adulthood. CDC and the Food and Drug Administration (FDA) analyzed data from the 2011-2015 National Youth Tobacco Surveys (NYTS) to determine the prevalence and trends of current (past 30-day) use of seven tobacco product types (cigarettes, cigars, smokeless tobacco, electronic cigarettes [e-cigarettes], hookahs [water pipes used to smoke tobacco], pipe tobacco, and bidis [small imported cigarettes wrapped in a tendu leaf]) among U.S. middle (grades 6-8) and high (grades 9-12) school students. In 2015, e-cigarettes were the most commonly used tobacco product among middle (5.3%) and high (16.0%) school students. During 2011-2015, significant increases in current use of e-cigarettes and hookahs occurred among middle and high school students, whereas current use of conventional tobacco products, such as cigarettes and cigars decreased, resulting in no change in overall tobacco product use. During 2014-2015, current use of e-cigarettes increased among middle school students, whereas current use of hookahs decreased among high school students; in contrast, no change was observed in use of hookahs among middle school students, use of e-cigarettes among high school students, or use of cigarettes, cigars, smokeless tobacco, pipe tobacco, or bidis among middle and high school students. In 2015, an estimated 4.7 million middle and high school students were current tobacco product users, and, therefore, continue to be exposed to harmful tobacco product constituents, including nicotine. Nicotine exposure during adolescence, a critical period for brain development, can cause addiction, might harm brain development, and could lead to sustained tobacco product use among youths. Comprehensive and sustained strategies are warranted to prevent and reduce the use of all tobacco products among U.S. youths.
- 3Zhu, S.-H. (2014) Four hundred and sixty brands of e-cigarettes and counting: implications for product regulation. Tobacco Control 23, iii3– iii9, DOI: 10.1136/tobaccocontrol-2014-051670Google ScholarThere is no corresponding record for this reference.
- 4Williams, M. and Talbot, P. (2011) Variability Among Electronic Cigarettes in the Pressure Drop, Airflow Rate, and Aerosol Production. Nicotine Tob. Res. 13, 1276– 1283, DOI: 10.1093/ntr/ntr164Google Scholar4https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC38%252Fis1CksA%253D%253D&md5=9215b58c84f2d0e73f9d3ec909fa30a6Variability among electronic cigarettes in the pressure drop, airflow rate, and aerosol productionWilliams Monique; Talbot PrueNicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco (2011), 13 (12), 1276-83 ISSN:.INTRODUCTION: This study investigated the performance of electronic cigarettes (e-cigarettes), compared different models within a brand, compared identical copies of the same model within a brand, and examined performance using different protocols. METHODS: Airflow rate required to generate aerosol, pressure drop across e-cigarettes, and aerosol density were examined using three different protocols. RESULTS: First 10 puff protocol: The airflow rate required to produce aerosol and aerosol density varied among brands, while pressure drop varied among brands and between the same model within a brand. Total air hole area correlated with pressure drop for some brands. Smoke-out protocol: E-cigarettes within a brand generally performed similarly when puffed to exhaustion; however, there was considerable variation between brands in pressure drop, airflow rate required to produce aerosol, and the total number of puffs produced. With this protocol, aerosol density varied significantly between puffs and gradually declined. CONSECUTIVE TRIAL PROTOCOL: Two copies of one model were subjected to 11 puffs in three consecutive trials with breaks between trials. One copy performed similarly in each trial, while the second copy of the same model produced little aerosol during the third trial. The different performance properties of the two units were attributed to the atomizers. CONCLUSION: There was significant variability between and within brands in the airflow rate required to produce aerosol, pressure drop, length of time cartridges lasted, and production of aerosol. Variation in performance properties within brands suggests a need for better quality control during e-cigarette manufacture.
- 5Goniewicz, M. L. (2014) Levels of selected carcinogens and toxicants in vapour from electronic cigarettes. Tobacco Control 23, 133– 139, DOI: 10.1136/tobaccocontrol-2012-050859Google Scholar5https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3svjvVGjtw%253D%253D&md5=85173602b1891dbeb7cded6135b3a52cLevels of selected carcinogens and toxicants in vapour from electronic cigarettesGoniewicz Maciej Lukasz; Knysak Jakub; Gawron Michal; Kosmider Leon; Sobczak Andrzej; Kurek Jolanta; Prokopowicz Adam; Jablonska-Czapla Magdalena; Rosik-Dulewska Czeslawa; Havel Christopher; Jacob Peyton 3rd; Benowitz NealTobacco control (2014), 23 (2), 133-9 ISSN:.SIGNIFICANCE: Electronic cigarettes, also known as e-cigarettes, are devices designed to imitate regular cigarettes and deliver nicotine via inhalation without combusting tobacco. They are purported to deliver nicotine without other toxicants and to be a safer alternative to regular cigarettes. However, little toxicity testing has been performed to evaluate the chemical nature of vapour generated from e-cigarettes. The aim of this study was to screen e-cigarette vapours for content of four groups of potentially toxic and carcinogenic compounds: carbonyls, volatile organic compounds, nitrosamines and heavy metals. MATERIALS AND METHODS: Vapours were generated from 12 brands of e-cigarettes and the reference product, the medicinal nicotine inhaler, in controlled conditions using a modified smoking machine. The selected toxic compounds were extracted from vapours into a solid or liquid phase and analysed with chromatographic and spectroscopy methods. RESULTS: We found that the e-cigarette vapours contained some toxic substances. The levels of the toxicants were 9-450 times lower than in cigarette smoke and were, in many cases, comparable with trace amounts found in the reference product. CONCLUSIONS: Our findings are consistent with the idea that substituting tobacco cigarettes with e-cigarettes may substantially reduce exposure to selected tobacco-specific toxicants. E-cigarettes as a harm reduction strategy among smokers unwilling to quit, warrants further study. (To view this abstract in Polish and German, please see the supplementary files online.).