ENDS Public Health

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Studies, Surveys, Papers, and Case Studies

  • Sometimes it's necessary to view the PDF version to access the full study.
  • This page is for referencing the possible benefits of ENDS products vs. smoking cigarettes from a Public Health standpoint. (Electronic Nicotine Delivery Systems are also known as vapor technology, e-cigarettes, ecigs, EVP, etc.)
  • If you'd prefer someone else to add a study to a topic, there is a subject section called "Suggested studies to add to this page". You may put the link in that section for one of the regular page editors to address.
  • If you'd like to help add content to this page, please see the directions at the bottom of the page.

2nd Hand Vapor

2022: Computational modeling method to estimate secondhand exposure potential from exhalations during e-vapor product use under various real-world scenarios

  • Acetaldehyde and acrolein were not detectable after use of any of the test products.
  • When these data were used as inputs to a computational room air level and non-user intake model, the ambient concentrations of exhaled nicotine and formaldehyde predicted that non-user intakes were substantially reduced for test product use compared to conventional cigarette use.
  • Collectively, the results predict that room air levels and exposure of the selected analytes to non-users were relatively low and several-fold below regulatory PELs and AIHA limit under the modeled space and use conditions.
  • ...room air levels of nicotine, formaldehyde, acrolein, and acetaldehyde levels were significantly below OSHA PELs or American Industrial Hygiene Association (AIHA) limit...

2020: Comparative Indoor Pollution from Glo, Iqos, and Juul, Using Traditional Combustion Cigarettes as Benchmark: Evidence from the Randomized SUR-VAPES AIR Trial

  • Glo, Iqos, and Juul have significantly less intense and persistent effects on indoor pollution in comparison to combustible tobacco cigarettes.

2018: Characterization of the Spatial and Temporal Dispersion Differences Between Exhaled E-Cigarette Mist and Cigarette Smoke

  • For both product categories, the particle concentrations registered following each puff were in the same order of magnitude. However, for e-cigarettes the particle concentration returned rapidly to background values within seconds; for conventional cigarettes it increased with successive puffs, returning to background levels after 30–45 minutes. Unlike for the e-cigarette devices tested, such temporal variation was dependent on the room ventilation rate. Particle size measurements showed that exhaled e-cigarette particles were smaller than those emitted during smoking conventional cigarettes and evaporated almost immediately after exhalation, thus affecting the removal of particles through evaporation rather than displacement by ventilation.

2017 Evaluation of Chemical Exposures at a Vape Shop

  • We collected air samples for flavoring chemicals (diacetyl, 2,3-pentanedione, 2,3-hexanedione, acetaldehyde, and acetoin), nicotine, formaldehyde, and propylene glycol.
  • Concentrations of vaping-related chemicals in our air samples were below occupational exposure limits.
  • Citation: NIOSH 2017. Evaluation of chemical exposures at a vape shop. By Zwack LM, Stefaniak AB, LeBouf RF. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Health Hazard Evaluation Report 2015-0107-3279

2017 Dr. Michael Siegel - Vape Shop Air Sampling by California State Health Department Suggests that Second Hand Vape Exposure is Minimal

  • This study, although conducted under very high exposure conditions in a small, non-ventilated vape shop with many employees and customers vaping and clouds of vapor visible, did not document any dangerous levels of exposure to any hazardous chemical. Nicotine exposure was essentially non-existent. Formaldehyde exposure was no different than in many indoor and outdoor environments at baseline. Acetone, acetoin, other aldehydes, toluene, benzene, and xylene were not detected. Chemicals that have been associated with "popcorn lung" were also not detected by the standard method.
  • This study adds to the evidence that under real-life conditions, "secondhand vaping" does not appear to pose any significant health risks.

2015: A rapid method for the chromatographic analysis of volatile organic compounds in exhaled breath of tobacco cigarette and electronic cigarette smokers

  • Tobacco cigarette smoke provided the samples containing highest concentrations of all compounds analyzed. Besides nicotine it contained benzene, toluene, xylenes, ethylbenzene and naphthalene in high abundance as well as other compounds such as isoprene, pent-1-ene, n-pentane, n-hexane, n-heptane and others.
  • This composition was in strong contrast with that of vapor from the e-cigarettes in which all these compounds were virtually absent except nicotine

2014: Peering through the mist: systematic review of what the chemistry of contaminants in electronic cigarettes tells us about health risks

  • Threshold Limit Values (TLVs), were conducted under “worst case” assumptions about both chemical content of aerosol and liquids as well as behavior of vapers.
  • There was no evidence of potential for exposures of e-cigarette users to contaminants that are associated with risk to health at a level that would warrant attention if it were an involuntary workplace exposures.
  • Exposures of bystanders are likely to be orders of magnitude less, and thus pose no apparent concern.

2012: Comparison of the effects of e-cigarette vapor and cigarette smoke on indoor air quality

  • Comparisons of pollutant concentrations were made between e-cigarette vapor and tobacco smoke samples. Pollutants included VOCs, carbonyls, PAHs, nicotine, TSNAs, and glycols.
  • Non-cancer risk analysis revealed “No Significant Risk” of harm to human health for vapor samples from e-liquids.
  • With regard to cancer risk analysis, no vapor sample from e-liquids exceeded the risk limit for either children or adults.

Continuum of Risk

2023: Time-varying association between cigarette and ENDS use on incident hypertension among US adults: a prospective longitudinal study.

  • Conclusions: We found that smoking increased the risk of self-reported hypertension, but ENDS use did not. These results highlight the importance of using prospective longitudinal data to examine the health effects of ENDS use.
  • Like the previous paper on asthma, the analysis is carefully designed to avoid bias/confounding from smoking history, and to avoid errors of temporal sequence (allowing data points where the outcome could have occurred prior to the exposure). This is especially valuable because of the concern that nicotine has direct cardiovascular effects – the evidence for which is mostly at a physiological level rather than a human clinical level. While this analysis does not prove the absence of an effect, it’s important nonetheless in raising doubts that ENDS have a clinically-meaningful cardiovascular effect at the population level.
  • Cook S, Hirschtick JL, Barnes G, Arenberg D, Bondarenko I, Patel A, Jiminez Mendoza E, Jeon J, Levy D, Meza R, Fleischer NL. BMJ Open. 2023 Apr 21;13(4):e062297. doi: 10.1136/bmjopen-2022-062297. PMID: 37085311 Free PMC article.

2023: Nicotine - friend or foe? The complex interplay between its role in dependence, harm reduction and risk communication.

  • So, how should we communicate the risks of nicotine? The quixotic attitude towards nicotine in our field has unintended consequences elsewhere. O’Brien et al.’s study of adolescents in the PATH study confirms findings in adults, including medical professionals, that nicotine is believed to cause smoking-related harms beyond addiction, such as cancer. Encouragingly, those having higher risk perceptions were less likely to start using nicotine-containing products a year later. Concerningly, even among adolescent smokers nearly half believed that nicotine in NRT was harmful, which may reduce the use of effective medication to help them stop smoking.
  • Clearly, no one wants to see a generation of nicotine-dependent youth, and more effective measures to limit access to nicotine, especially combustible nicotine, are needed. But when it comes to communicating research to the wider public, we must avoid conflating the relatively limited harm of nicotine dependence with its effects on maintaining tobacco addiction, and therefore well-established tobacco-related harm, not least because of the impact this has on risk perceptions of those most in need of nicotine-based treatment: Tobacco users.
  • This is a valuable commentary because it acknowledges the concerns about nicotine use and dependence, but points out the major danger in overemphasizing the associated risks  (perpetuating the most harmful form of nicotine). There seems to be a common ends-justify-the-means attitude that condones or even encourages greater risk perceptions (especially among youth) in the hopes that it will deter them from using nicotine, but Dr. Shahab points out the obvious public health risks of this as well.
  • Shahab L. Nicotine Tob Res. 2023 Apr 15:ntad053. doi: 10.1093/ntr/ntad053. Online ahead of print. PMID: 37061812 No abstract available.

2020: E-cigarettes and their impact on health: from pharmacology to clinical implications

Despite many areas of ambiguity, current evidence suggest that e-cigarettes are less harmful than combustible products, but this only applies to smokers who completely switched to e-cigarettes. Thus, e-cigarettes still hold a great potential to reduce incidences of tobacco-related diseases and could be a part of the strategy to reduce the damage caused by smoking. Therefore, mechanisms should be developed to protect young people from using e-cigarettes but support smokers in their decisions to quit smoking with e-cigarettes.

2020: The ethics of tobacco harm reduction: An analysis of e-cigarette availability from the perspectives of utilitarianism, bioethics, and public health ethics

Much evidence suggests e-cigarettes are substantially less harmful than combustible cigarettes. E-Cigarette Availability (ECA) involves making e-cigarettes available to allow smokers to switch to them, and informing smokers of the lower risks of e-cigarettes vis-à-vis smoking. First, ECA is supported by a public health ethics framework. ECA is a population-level intervention consistent with respecting individual autonomy by using the least restrictive means to accomplish public health goals, and it supports equity and justice. Second, ECA is supported by four principles that form a biomedical ethics framework. By reducing smokers' health risks and not harming them, ECA fulfills principles of beneficence and non-maleficence. Because ECA allows smokers to make informed health decisions for themselves, it fulfills the principle requiring respect for persons and their autonomy. ECA can also advance justice by providing a harm reduction alternative for disadvantaged groups that disproportionately bear the devastating consequences of smoking. Policies of differential taxation of cigarettes and e-cigarettes can facilitate adoption of less harmful alternatives by those economically disadvantaged. We conclude that public health and biomedical ethics frameworks are mutually reinforcing and supportive of ECA as a tobacco harm reduction strategy.

2018: Harm Minimization and Tobacco Control: Reframing Societal Views of Nicotine Use To Rapidly Save Lives

FDA’s Gottlieb & Zeller state: “Nicotine,though not benign, is not directly responsible for the tobacco-caused cancer, lung disease and heart disease that kill hundreds of thousands of Americans each year” Inhalation of the toxic smoke produced by combusting tobacco products,primarily cigarettes, is the overwhelming cause of tobacco-related disease and death in the United States and globally. A diverse class of alternative nicotine delivery systems (ANDS) has recently been developed that do notcombust tobacco and are substantially less harmful than cigarettes. ANDS have the potential to disrupt the 120-year dominance of the cigarette and challenge the field on how the tobacco pandemic could be reversed if nicotine is decoupled from lethal inhaled smoke. ANDS may provide a means to compete with, and even replace, combusted cigarette use, saving more lives more rapidly than previously possible. Most reviews of toxicological, clinical, and epidemiological evidence indicate that the chemicals found in e-cigarettes, when used as intended, are far fewer and well below levels seen in cigarette smoke Studies in humans have also documented improved physiological outcomes, including reduced blood pressure, improved lung function, andlower disease symptoms, among smokers who switched to e-cigarettes E-cigarettes are much less dependence-producing than are cigarettes The potential harm of e-cigarettes falls in the low range on the continuum

2017: Potential deaths averted in USA by replacing cigarettes with e-cigarettes

Compared with the Status Quo, replacement of cigarette by e-cigarette use over a 10-year period yields 6.6 million fewer premature deaths with 86.7 million fewer life years lost in the Optimistic Scenario. Under the Pessimistic Scenario, 1.6 million premature deaths are averted with 20.8 million fewer life years lost. The largest gains are among younger cohorts, with a 0.5 gain in average life expectancy projected for the age 15 years cohort in 2016. The tobacco control community has been divided regarding the role of e-cigarettes in tobacco control. Our projections show that a strategy of replacing cigarette smoking with vaping would yield substantial life year gains, even under pessimistic assumptions regarding cessation, initiation and relative harm.

2016: Obsolete tobacco control themes can be hazardous to public health: the need for updating views on absolute product risks and harm reduction

Implications of updating the leading themes for regulation, policymaking and advocacy in tobacco control are proposed as an important next step. A new reframing can align action plans to more powerfully and rapidly achieve population-level benefit and minimize harm to eliminate in our lifetime the use of the most deadly combustible tobacco products and thus prevent the premature deaths of 1 billion people projected to occur worldwide by 2100

2016: Withholding differential risk information on legal consumer nicotine/tobacco products: The public health ethics of health information quarantines

The straight-forward principles of harm reduction should be as uncontroversial for tobacco products as they are for alcohol, cars, air travel, children's clothing, sexual practices, electrical goods and other goods and activities. Concerns for some adverse public health effects of harm reduction products such as SLT (Smokeless Tobacco) and vape are reasonable and worth trying to minimize, but there is no current evidence that such products actually represent an imminent danger to public health overall. Efforts to discourage the use of tobacco/nicotine products need not be reduced, but should be done in a harm-proportionate way. Telling consumers that all product options are as bad as cigarettes is untrue and almost certainly as deadly for users as telling at-risk populations that condom use affords no protection.

2016: Ethical considerations of e-cigarette use for tobacco harm reduction

Current evidence suggests that e-cigarettes have the potential to make significant public health gains through their role as tobacco harm reduction devices. In clinical practice, physicians have an ethical duty to provide their patients with evidence-based comparative risk assessments to allow them to make informed choices with respect to their smoking status. At its core, the objective of the smoking cessation agenda should be to improve population health, which will likely require some concessions in the form of harm reduction. This entails a willingness to negotiate the tensions between utilitarian and liberal ethics in designing policy that upholds autonomy while protecting broader public health interests.

2014: Estimating the Harms of Nicotine-Containing Products Using the MCDA Approach

The group defined 12 products and 14 harm criteria. Seven criteria represented harms to the user, and the other seven indicated harms to others. The results of this study suggest that of all nicotine-containing products, cigarettes (and small cigars in the USA) are very much the most harmful. Interventions to reduce this pre-eminence are likely to bring significant benefits not just to users but also to non-smokers and society as a whole. Attempts to use other forms of nicotine such as ENDS and NRT to reduce cigarette smoking should be encouraged as the harms of these products are much lower.

Risk Graph

Dependence (Addiction, Abuse) vs Harm / Harm Reduction - Ecigs and Nicotine

2023: Individual and conjoint factors associated with beliefs about the harmfulness of nicotine replacement therapies relative to combustible cigarettes among people who smoke: Findings from the 2020 ITC Four Country Smoking and Vaping Survey.

  • An analysis of risk perceptions of NRT vs cigarettes among adults (18+) in ITC data:
  • Results: Percentages believing that NRTs are much less harmful than CCs were 29.7% (95% CI:26.2-33.5%) in Australia, 27.4% (95% CI=25.1-29.8%) in England, 26.4% (95% CI=24.4-28.4%) in Canada and 21.7% (95% CI=19.2-24.3%) in the US.
  • Another data point confirming the abysmal risk perceptions around nicotine products. Since these data were from 2020, it’s likely that things have gotten even worse since then. As the analysis goes on to show, different variations on nicotine misperceptions are correlated with each other:
    • Across all countries, believing nicotine is not at all/slightly harmful to health (aOR=1.53-2.27), endorsing nicotine vaping products as less harmful than CCs (much less harmful: aOR=7.24-14.27; somewhat less harmful: aOR=1.97-3.23), and possessing higher knowledge of smoking harms (aOR=1.23-1.88) were individual factors associated with increased odds of believing NRTs are much less harmful than CCs.
  • Echoing comments from the E-Cig Summit last week, this calls for some much-needed communication from government health agencies around authorized nicotine products to better inform adults who smoke about less-harmful alternatives.

2023: 2013-2017: a multistate Markov transition analysis

  • Results: Sole cigarette and SLT use were persistent, with 77% and 78% of adults continuing use after one wave. Other use states were more transient, with 29%–48% of adults reporting the same pattern after one wave. If single-product users transitioned, it was most likely to non-current use while dual or poly cigarette users were most likely to transition to exclusive cigarette use.
  • It's notable that e-cigarette use was more transient (~46%), which corroborates other evidence that much of e-cigarette use was experimental in nature and did not lead to regular or long-term use. Even more notable is that this was during a period of continually rising e-cigarette use (2013-2017); since youth e-cigarette use has declined again in more recent years, I would expect later waves of data to show even less persistence of use.
  • Review of PATH Waves 1-4
  • Shafie Khorassani F, Brouwer AF, Hirschtick JL, Jeon J, Jimenez-Mendoza E, Meza R, Fleischer NL. Tob Control. 2023 Apr 24:tc-2022-057822. doi: 10.1136/tc-2022-057822. Online ahead of print. PMID: 37094934

2020: Dependence on e‐cigarettes and cigarettes in a cross‐sectional study of US adults

Among current users, dependence on e‐cigarettes was significantly lower than dependence on cigarettes, in within‐subjects comparisons among dual users of both e‐cigarettes and cigarettes, and in separate groups of e‐cigarette users and cigarette smokers, and among both daily and non‐daily users of each product. Among former users, residual symptoms were significantly lower for e‐cigarettes than cigarettes, both among former dual users and among users of one product. The highest level of e‐cigarette dependence was among e‐cigarette users who had stopped smoking. Use of e‐cigarettes appears to be consistently associated with lower nicotine dependence than cigarette smoking.

2017: A comparison of nicotine dependence among exclusive E-cigarette and cigarette users in the PATH study

Cigarette smokers are more likely to consider themselves addicted, to have strong cravings, and to feel like they really needed to use their product. Cigarette smokers found it more difficult not to use in places where prohibited. E-cig users report less dependence on their product than cigarette smokers. E-cig users report a longer time-to-first-use after waking. These results are consistent with previous studies, in finding that exclusive daily e-cigarette users are less dependent on their respective product than comparable cigarette smokers.

2017: Evaluating nicotine dependence levels in e-cigarette users

Results showed that e-cigarette users scored lower than cigarette smokers in both FTND (Fagerström test for nicotine dependence) and all NDSS (nicotine dependence syndrome scale) subscales. Our findings extend previous research on e-cigarette use and nicotine addiction and suggest that e-cigarette users are less dependent on nicotine than current tobacco cigarette smokers.

2017: E-cigarettes: Impact of E-liquid Components and Device Characteristics on Nicotine Exposure

Given the large range of factors that can impact nicotine delivery, not only within the e-liquids but also in the hardware and user behavior, any regulatory framework intended to moderate nicotine exposure in users may not achieve its intended aim if it is solely limited to a regulation of the nicotine concentration of the e-liquid.

2014: Dependence levels in users of electronic cigarettes, nicotine gums and tobacco cigarettes

E-cigarettes may be as or less addictive than nicotine gums, which themselves are not very addictive.

2013: A fresh look at tobacco harm reduction: the case for the electronic cigarette

“Thus even if 50% of the non-smoking population should decide to addict itself to nicotine via an E-cig, the associated disease risks, if any, would be minimal. Thus, “abuse liability” is a moot point in this context.”

2012: Dependence on Tobacco and Nicotine Products: A Case for Product-Specific Assessment

Conclusion: “The other suggestion made is that when the totality of the dependence is measured, different forms of tobacco/nicotine products probably have different potential for dependence development. There might be a continuum of dependence where in one end, we find the cigarette and in the other end, NR products and particularly the patch formulation. If a particular product is far from cigarettes and close to NR on the continuum of harm and at the same time closer to cigarettes than NR on the continuum of dependence, this product may have considerable success in reducing the public health costs associated with cigarette use.”

2012: Clinical laboratory assessment of the abuse liability of an electronic cigarette

Electronic cigarettes can deliver clinically significant amounts of nicotine and reduce cigarette abstinence symptoms and appear to have lower potential for abuse relative to traditional tobacco cigarettes.

2011: Electronic cigarettes as a harm reduction strategy for tobacco control: A step forward or a repeat of past mistakes?

We conclude that electronic cigarettes show tremendous promise in the fight against tobacco-related morbidity and mortality. By dramatically expanding the potential for harm reduction strategies to achieve substantial health gains, they may fundamentally alter the tobacco harm reduction debate.


2019 Article: New smoking statistics shows ‘gray vaping’ is on the rise in the UK

Sorry link dead, please let us know if you know where this can be found!

2019 PDF of Study (43 pages) NHS Statistics on Smoking

Link now dead, if anyone has a copy or link please let us know, thanks!


2021: Ethics and Harm Reduction Approaches in Tobacco Control (Special journal edition)

  • This special issue of Nicotine and Tobacco Research focuses on the ethical aspects of tobacco harm reduction as a strategy in tobacco control. Several of the papers arise from presentations given in May 2018 at a Summer Academy on population-level bioethics hosted by the Brocher Foundation, organized by Samia Hurst, Dan Wikler, Nir Eyal, and Monica Magalhaes, specifically focusing on tobacco control. This event led to a call for papers for this journal.
  • The polarization of this debate and the impact this has on trainees and early career researchers and professionals in the field of nicotine and tobacco is discussed in the commentary by Carroll and colleagues.
  • This further motivates the search for ethical principles, which can explain why participants in these debates take the positions they do, and assist us to find an ethical position that can clarify and guide policy choice.
  • Thomas and colleagues consider the debate from the point of view of three major analytical approaches in bioethics—utilitarianism, (individual oriented) bioethics, and public health ethics—arguing that the first is not adequate to tackle the problems, but that the latter approaches are in fact complementary and draw to similar conclusions.
  • The papers in this issue consider what may be familiar problems to most readers of this journal, but in possibly unfamiliar ways drawing from the discipline of philosophy.

2019: A critical analysis of Australia’s ban on the sale of electronic nicotine delivery systems

  • Australia does not allow adult smokers to buy or use electronic nicotine delivery systems (ENDS) that contain nicotine without a prescription. This paper critically evaluates the empirical and ethical justifications provided for the policy by Federal and State governments, public health advocates and health organisations.
  • We also argue that even if the evidence were stronger, it would not justify denying adult smokers the right to use ENDS either to quit smoking or as a long-term alternative to smoking cigarettes.
  • We outline ENDS policies that would more ethically address the public health concerns that motivated the current policy by allowing adult smokers to access ENDS for smoking cessation or tobacco harm reduction under tight regulations that discourage commercial promotion and adolescent use.
  • Hall, W., Morphett, K. & Gartner, C. A Neuroethics 14 (Suppl 3), 323–331 (2021). https://doi.org/10.1007/s12152-019-09402-x

Mental Health

2020: E-cigarette use and associated factors among smokers with severe mental illness

Among participants, mean age was 46 years, the majority (70.3%) had tried an e-cigarette. Among those who had ever tried an e-cigarette, over half (54.6%) reported the reason was to quit smoking, while 13.9% reported that the reason was to reduce smoking.

2020: A qualitative study of the views about smoking, licensed cessation aids and e-cigarettes in people with schizophrenia spectrum disorders

There is a need to find ways of making traditional cigarettes less appealing and alternative less harmful nicotine products (licensed and unlicensed) more appealing and accessible to this group of high risk smokers.

2014: Use of e-cigarettes by individuals with mental health conditions

Individuals with mental health conditions (MHC) have disproportionately high tobacco-related morbidity and mortality due to high smoking prevalence rates. As high consumers of cigarettes, smokers with MHC may consider using e-cigarettes as an alternative form of nicotine delivery. Individuals with MHC were more likely to have tried e-cigarettes (14.8%) and to be current users of e-cigarettes (3.1%) than those without MHC (6.6% and 1.1%, respectively; p<0.01). Ever smokers with MHC were also more likely to have tried approved pharmacotherapy (52.2% vs 31.1%, p<0.01) and to be currently using these products (9.9% vs 3.5%, p<0.01) than those without MHC. Additionally, current smokers with MHC were more susceptible to future use of e-cigarettes than smokers without MHC (60.5% vs 45.3%, respectively, p<0.01). Smokers with MHC are differentially affected by the rise in popularity of e-cigarettes. Clinical interventions and policies for tobacco control on e-cigarettes should take into account the possible outcomes and their implications for this priority population.

2013: Impact of an Electronic Cigarette on Smoking Reduction and Cessation in Schizophrenic Smokers: A Prospective 12-Month Pilot Study

Even with intensive smoking cessation management programs specifically designed for patients with schizophrenia, quit rates are low. Although not formally regulated as a pharmaceutical product, the e-cigarette can help smokers with schizophrenia to reduce their cigarette consumption or remain abstinent and reduce the burden of smoking-related morbidity and mortality, particularly in schizophrenic patients who smoke

2011: Smoking Cessation with E-Cigarettes in Smokers with a Documented History of Depression and Recurring Relapses

The most important message from this case series is that these individuals were able to quit and to remain abstinent for at least 6 months after taking up an electronic cigarette. This is the first time that objective measures of smoking cessation are reported in smokers, suffering from depression, who quit after experimenting with the e-cigarette. This is quite outstanding in consideration of the fact that this result was accomplished by highly addicted smokers who repeatedly failed professional smoking cessation assistance without the support of recommended nicotine dependence treatments and smoking cessation counselling.

See Also

Never Smokers

2024: A Global Health Survey of People Who Vape but Never Smoked: Protocol for the VERITAS (Vaping Effects: Real-World International Surveillance) Study

  • There is only limited information about the health effects of regular vaping. Research on the health status of people who used to smoke faces the challenge that previous smoking may have caused unknown health effects. Only studies of people who vape but have never smoked combustible cigarettes can enable the detection of harms attributable to vaping.
  • Large prospective studies of well-characterized electronic cigarette users with and without a history of combustible cigarette smoking are warranted to establish the long-term effects of regular vaping on respiratory health.
    • We will conduct a global cross-sectional survey of individuals from 6 world regions. Respiratory symptoms will be assessed using a validated questionnaire-the Respiratory Symptom Experience Scale (RSES). Current vapers who are nonusers of other tobacco or nicotine products will be compared with matched controls who are nonusers of vapes and other tobacco or nicotine products.
    • This will be a multicountry, cross-sectional internet-based survey of 750 adults aged ≥18 years who satisfy the criteria for inclusion in either a cohort of people who exclusively vape and who are nonusers of other tobacco or nicotine products ("vapers cohort"; target N=500) or a cohort of nonvapers who are also nonusers of other tobacco or nicotine products ("controls cohort"; target N=250).
  • Participant recruitment started in April 2023, and enrollment was completed by November 2023 with 748 participants. Results will be reported in 2024.
  • https://www.researchprotocols.org/2024/1/e54236

2020: E-Cigarettes and Respiratory Disease: A Replication, Extension, and Future Directions

  • The statistical associations between e-cigarette use and respiratory disease are driven by e-cigarette users who are also current or former smokers of combustible tobacco.
  • A striking feature of the data is that almost all e-cigarette users were either current or former smokers of combustible tobacco.
  • Among respondents who had never smoked combustible tobacco, we find no evidence that current or former e-cigarette use is associated with respiratory disease.

Link to PDF

2020: Electronic Cigarette Use Among U.S. Adults, 2018

In 2018, 34 million U.S. adults were current smokers, and 55 million were former cigarette smokers for any duration (5). E-cigarette use was highest among current smokers and former smokers who quit cigarettes within the past year and those who quit 1–4 years ago. The percentages who had ever used an e-cigarette or who were current e-cigarette users declined among former smokers who had gone longer without smoking cigarettes and was lowest among those who never smoked cigarettes.

2017: Health impact of E-cigarettes: a prospective 3.5-year study of regular daily users who have never smoked

In a small sample of young-adult never-smoking, daily EC users who were carefully followed for approximately 3½ years, we found no decrements in spirometric indices, development of respiratory symptoms, changes in markers of lung inflammation in exhaled air or findings of early lung damage on HRCT, when compared with a carefully matched group of never-smoking non-EC users. Even the heaviest EC users failed to exhibit any evidence of emerging lung injury as reflected in these physiologic, clinical or inflammatory measures. Moreover, no changes were noted in blood pressure or heart rate. Since the EC users who we studied were never smokers, potential confounding by inhalation of combustion products of tobacco were obviated. While the sample size was small, the results of this study may provide some preliminary evidence that long-term use of ECs is unlikely to raise significant health concerns in relatively young users

2016: Visible Vaping: E-Cigarettes and the Further Denormalization of Smoking

Visible vaping was commonly reported by interviewees who typically interpreted such vaping as indicating that the individual was seeking to reduce or cease his or her smoking. Whilst the sight of someone using an e-cigarette could stimulate curiosity on the part of non-smokers as to what the experience of vaping was like there was little indication that our sample of non-smokers were intending taking up vaping on a regular basis. There were indications from our interviews that visible vaping had resulted in either no change in what individuals assessed as their likelihood of to smoke and for a minority of interviewees visible vaping had resulted in a reduced likelihood of smoking as assessed by interviewees. To the extent that electronic cigarette use remains distinguishable from smoking combustible cigarettes there is a possibility that vaping may be associated with further denormalization of smoking.


Please visit the Nicotine - Pregnancy - Nursing page for more information.

Perception - safety vs harm - effects on use

2023: Medicalisation of vaping in the UK? E-cigarette users' perspectives on the merging of commercial and medical routes to vaping.

  • An important paper, investigates the co-existence, synergies and tensions between the two models of vaping for public health - the medicalised and consumer-based approaches - drawing on the insights of users.  Great subject, because these two models have entirely different modes of engagement and action.  We would ideally like both to work, but it could be problematic if one compromised the impact of the other.
    • Three qualitative themes were identified: pro-partnership, anti-partnership and medicalisation dissonance. Medicalisation was discussed for its potential to reassure smokers about e-cigarette harms and its potential to reach smokers from disadvantaged backgrounds. Concerns were raised about cost-effectiveness, quality of support, conflicts of interest and limiting product choice. Most participants rated interventions involving partnership working as potentially helpful in switching from smoking to vaping. There were no statistically significant associations between age, gender and socioeconomic status, and helpfulness ratings.
  • Being qualitative, the paper is sprinkled with revealing quotes from vapers... e.g.
    • [Millions of] people are now using e-cigarettes in the UK and that this change came about with no involvement of any health professionals whatever. My guess is that the best thing would be for health professionals to leave things as they are, while doing everything they can to counteract adverse media reportage and trumpet the benefits of switching from smoking to e-cigarette use. (Survey participant 21)
  • The authors see complementary benefits in pursuing both models...
    • Conclusion: Both commercial and medical routes to vaping offer perceived benefits to vapers and may complement and reinforce each other to support smoking cessation.
  • Ward E, Dawkins L, Holland R, Pope I, Notley C. Perspect Public Health. 2023 Aug 6:17579139231185481. doi: 10.1177/17579139231185481. Online ahead of print. PMID: 37544328

2023: Awareness and beliefs about FDA e-cigarette regulation in the premarket application review era.

  • A survey of awareness and attitudes about regulation of e-cigarettes, among adults who smoke and youth (15-20):
  • Awareness that FDA regulates e-cigarettes was low among adults who smoke (25.4 %) and youth (18.5 %). Awareness that FDA authorizes e-cigarettes was also low among adults who smoke (10.8 %) and youth (12.7 %).
  • Additionally, participants were asked about two positive beliefs regarding regulation (“agree that FDA regulation makes e-cigarettes safer”, ~40%; “agree that FDA regulation helps prevent youth uptake”, ~25%), and two negative beliefs (“agree that FDA regulation takes away freedom to choose”, ~20%; “agree that FDA regulation limits choices”, ~40%). Current e-cigarette use was associated with higher odds of agreeing to each item (both positive and negative beliefs).
  • Seems to indicate a lot of confusion about regulation, and responses that are not always consistent (e.g. the two negative beliefs are both about choice, but have very different rates of endorsement).
  • Again this is very timely considering conversations during this week’s E-Cig Summit: given the low awareness of e-cigarettes among the population who would benefit most from them (adults who smoke), seems like a prime opportunity for some communication from FDA about authorized e-cigarette products.
  • Weiger C, Chen-Sankey J, Jeong M, Delnevo C, Wackowski O. Addict Behav. 2023 May 9;144:107748. doi: 10.1016/j.addbeh.2023.107748. Online ahead of print. PMID: 37182238

2023: US Physicians' Self-reported Discussions About Tobacco-Free Nicotine Pouches During Clinical Encounters With Patients in 2021.

  • This survey asked US physicians whether patients have asked them about nicotine pouches, and some characteristics about those conversations:
    • Results: Of 745 participating physicians, 63 (9.7%) reported being asked by patients about tobacco-free nicotine pouches… Fifty respondents described patient discussions about nicotine pouches, which clustered into 3 themes: discouraging use of pouches (20 [40.0%]), learning about nicotine pouches from patients or neutral communication (19 [38.0%]), and communicating to patients that they were open to pouch use for cessation or harm reduction (11 [22.0%]).
  • These numbers are remarkably similar to risk perceptions overall in the US if you map the physician response categories onto different risk perception categories: the largest group incorrectly thinks that noncombustible nicotine products are harmful and should be discouraged, followed by a large minority who doesn’t know one way or another, and only ~20% viewing noncombustible nicotine products as less risky. In other words, doctors are just as confused and misinformed about nicotine as most of the rest of us.
    • Discussion: Previous guidance on e-cigarettes may be helpful to inform physicians’ approach to nicotine pouches—in a discussion of cigarette substitutes, clinicians should urge patients to quit or reduce combustible tobacco use, and while the effects of long-term nicotine pouch use remain unknown, such products are likely less harmful than combustible tobacco.
  • Hrywna M, Bover-Manderski MT, Wackowski OA, Steinberg MB, Delnevo CD. JAMA Netw Open. 2023 May 1;6(5):e2313583. doi: 10.1001/jamanetworkopen.2023.13583. PMID: 37191964 Free PMC article.

2020: Perception of the relative harm of electronic cigarettes compared to cigarettes amongst US adults from 2013 to 2016: analysis of the Population Assessment of Tobacco and Health (PATH) study data

In this study, the proportion of US adults who incorrectly perceived e-cigarettes as equal to, or more, harmful than cigarettes increased steadily regardless of smoking or vaping status. Current adult smokers appear to be poorly informed about the relative risks of e-cigarettes yet have potentially the most to gain from transitioning to these products. The findings of this study emphasise the urgent need to accurately communicate the reduced relative risk of e-cigarettes compared to continued cigarette smoking and clearly differentiate absolute and relative harms. The lack of accurate and consistent messaging from both public health agencies and the media may be contributing to public, and more specifically adult smokers’, perceptions about the relative risk of nicotine when decoupled from combustion and tobacco smoke. Confusion may potentially be discouraging adult smokers from using alternative, less hazardous products which may ultimately result in a missed opportunity to positively impact health at both an individual and population level.

2020: Association between changes in harm perceptions and e-cigarette use among current tobacco smokers in England: a time series analysis

There is a decreasing trend in the proportion of individuals who perceive e-cigarettes to be less harmful than conventional cigarettes across the UK, Europe and the US. For every 1% decrease in the mean prevalence of current tobacco smokers who endorsed the belief that e-cigarettes are less harmful than combustible cigarettes, the mean prevalence of e-cigarette use decreased by 0.48% Between 2014 and 2019 in England, at the population level, monthly changes in the prevalence of accurate harm perceptions among current tobacco smokers were strongly associated with changes in e-cigarette use.


The increase in e-cigarette risk perceptions might discourage adult smokers from using e-cigarettes as a way to quit smoking, despite evidence from a clinical trial that ecigarettes are a more effective cessation method than FDA-approved products such as the nicotine patch. Our econometric results suggest that the immediate impact of the first information shock was to increase the fraction of respondents who perceived e-cigarettes as more harmful than smoking by about 16 percentage points. More targeted advice about the risks of THC e-cigarettes (vs nicotine products) might have more effectively reduced the use of those products, potentially preventing EVALI cases.

  • PDF Version
  • Citation: Dave, D., Dench, D., Kenkel, D. et al. News that takes your breath away: risk perceptions during an outbreak of vaping-related lung injuries. J Risk Uncertain 60, 281–307 (2020). doi: 10.1007/s11166-020-09329-2
  • Acknowledgement: Dhaval Dave acknowledges support through grant R01DA039968 from the National Institute on Drug Abuse. The authors are grateful to Cornell University and the Health Thought Leadership Network at Bentley University for funding the data collection.

2014 Characteristics, Perceived Side Effects and Benefits of Electronic Cigarette Use: A Worldwide Survey of More than 19,000 Consumers

In this large sample of dedicated EC users, it seems that ECs are used as long-term substitutes to smoking. They can be effective even in subjects who are highly dependent on smoking and are heavy smokers. Mild temporary side-effects and significant benefits are reported by this population. Motivation for using ECs comes from their expected less harmful potential compared to smoking.

Propylene Glycol

2009: Propylene glycol in e cigarettes might keep us healthy, says researchers

“Propylene glycol, the primary ingredient in the electronic cigarette cartridge, may be a powerful deterrent against pneumonia, influenza, and other respiratory diseases when vaporized and inhaled according to a study by Dr. Oswald Hope Robertson. Decades before the e cigarette was invented, a study was conducted by Dr. Robertson of the University of Chicago's Billings Hospital in 1942 on inhalation of vaporized propylene glycol in laboratory mice. A more in-depth article was printed in the 1942 issue of TIME Magazine http://www.time.com/time/magazine/article/0,9171,932876,00.html for November 16th. "Dr. Robertson placed groups of mice in a chamber and sprayed its air first with propylene glycol, then with influenza virus. All the mice lived. Then he sprayed the chamber with virus alone. All the mice died."” The researchers also found that "the propylene glycol itself was a potent germicide. One part of glycol in 2,000,000 parts of air would--within a few seconds--kill concentrations of air-suspended pneumococci, streptococci and other bacteria numbering millions to the cubic foot."


  • Comparative observations on the growth rates, blood counts, urine examinations, kidney function tests, fertility and general condition of the test and control groups, exhibited no essential differences between them with the exception that the rats in the glycol atmospheres exhibited consistently higher weight gains. Some drying of the skin of the monkeys' faces occurred after several months continuous exposure to a heavy fog of triethylene glycol. However, when the vapor concentration was maintained just below saturation by means of the glycostat this effect did not occur.
  • Examination at autopsy likewise failed to reveal any differences between the animals kept in glycolized air and those living in the ordinary room atmosphere. Extensive histological study of the lungs was made to ascertain whether the glycol had produced any generalized or local irritation. None was found. The kidneys, liver, spleen and bone marrow also were normal.
  • The results of these experiments in conjunction with the absence of any observed ill effects in patients exposed to both triethylene glycol and propylene glycol vapors for months at a time, provide assurance that air containing these vapors in amounts up to the saturation point is completely harmless.
  • Animal study
  • O. H. ROBERTSON, CLAYTON G. LOOSLI, THEODORE T. PUCK, HENRY WISE, HENRY M. LEMON and WILLIAM LESTER JR. Journal of Pharmacology and Experimental Therapeutics September 1947, 91 (1) 52-76;


It has been found that propylene glycol vapor dispersed into the air of an enclosed space produces a marked and rapid bactericidal effect on microorganisms introduced into such an atmosphere in droplet form. Concentrations of 1 gm. of propylene glycol vapor in two to four million cc. of air produced immediate and complete sterilization of air into which pneumococci, streptococci, staphylococci, H. influenzae, and other microorganisms as well as influenza virus had been sprayed….


2018: Lack of Substantial Post-Cessation Weight Increase in Electronic Cigarettes Users

  • “Conclusion: Within the study limitations, EC use may help smokers attenuate cigarette consumption or remain abstinent, as well as reduce their post-cessation weight increase. The potential role of the e-vapour category for harm minimization in relation to tobacco and/or food abuse requires confirmation from larger prospective studies. Moreover, the observed lack of post-cessation weight gain in those who reduced substantially cigarette consumption by switching to ECs (i.e., dual users) is an interesting finding and calls for further research investigating the role of nicotine in weight control. Meanwhile, these preliminary findings should be communicated to smokers and particularly to weight-conscious smokers intending to quit.
  • By combining substantial reduction of smoking with prevention of post-cessation weight gain, EC-based interventions may promote an overall improvement in quality of life. Considering that the negative effects of weight increase could overshadow the health benefits of smoking abstinence, it is important to stimulate more research in this area.”

2018: E-cigarettes and Weight Loss—Product Design Innovation Insights From Industry Patents

E-cigarettes may be presented to cigarette users as a possible solution to support smoking cessation and address the fear of weight gain.

2017: Could Vaping be a New Weapon in the Battle of the Bulge?

Obesity is set to overtake tobacco smoking in many countries as the primary cause of several high-cost diseases. Tobacco smoking mitigates weight gain through nicotine’s effect on the brain and metabolism. There have been some reports among vapers that vaping is helping to mitigate weight gain after stopping smoking and or vaping is helping them to control their weight. There are several potential mechanisms by which vaping, in addition to the direct effects of nicotine, could facilitate weight control, these include taste perception, physical mouthfeel, and sensation and behavioral replacement.

See Also

PAGE EDITORS - Please only add Studies, Surveys, Papers in this format to keep page organized

  • Topic
  • Year (list new to old) Name of Study (In link format to the study)
  • Note here if animal study (leave blank if not)
  • Brief Summary
  • Link to PDF Version
  • Citation
  • Acknowledgements (funded by, helped by)
  • Keywords
  • Other

Suggested studies to add to this page

The data reliability pyramid. Shows the quality of various data from expert opinion at the bottom to systematic review at the top (lowest quality at bottom, highest at top)
The data reliability pyramid

2023: Vaping: Government announces "swap to stop" scheme to cut smoking rates.

  • One million smokers in England will be given a free vaping starter kit as part of a government package of measures to get smoking rates below 5% by 2030
  • Comment and write up in BMJ of UK policy.

2023: Preprint Propylene glycol inactivates respiratory viruses and prevents airborne transmission

  • Mouse study
  • Preprint not yet published
  • Christine T. Styles, Jie Zhou, Katie E. Flight, Jonathan C. Brown, Michael Vanden Oever, Thomas P. Peacock, Ziyin Wang, Rosie Millns,  John S. O’Neill, Wendy S. Barclay, John S. Tregoning,  Profile Rachel S. Edgar doi: https://doi.org/10.1101/2023.02.13.528349

2021: Interventions for preventing weight gain after smoking cessation

  • There was moderate‐certainty that NRT reduced weight at end of treatment and moderate‐certainty that the effect may be similar at 12 months, although the estimates are too imprecise to assess long‐term benefit.

2022: Cross-sectional e-cigarette studies are unreliable without timing of exposure and disease diagnosis

2022: Do Young People Perceive E-Cigarettes and Heated Tobacco as Less Harmful Than Traditional Cigarettes? A Survey from Poland

  • The results of the study showed that 52.2% and 61.9% of young people perceive e-cigarettes and heated tobacco products as less harmful compared to traditional cigarettes, respectively.
  • Note: They are correct in perception.

2022: Youth E-Cigarette Use and Functionally Important Respiratory Symptoms: The Population Assessment of Tobacco and Health (PATH) Study Waves 3 and 4

  • Exposure was e-cigarette use status (never, former, or current) at [PATH Wave 3]. The outcome was a respiratory symptom index based on responses for seven wheezing items at Wave 4.
  • Baseline e-cigarette use did not increase the odds of having functionally important respiratory symptoms at follow-up regardless of combustible tobacco use status.

Click on the category link below for more studies by topic on ENDS and Nicotine.