1. Effects of Electronic Cigarette Use on Myocardial Function
Dr. Konstantinos Farsalinos
You’ll see Dr. Farsalinos’ work mentioned several times throughout this blog. Dr. Farsalinos is a cardiac specialist from Greece who has dedicated many hours in recent over the last four years to studies in which e-cig vapour is studied and compared to cigarette smoke.
I have chosen this study, conducted between 2011 and 2012, as the first on my list because it set the groundwork for every subsequent electronic cigarette investigation by Farsalinos and his team. It is the first of its kind that presents clinical evidence regarding e-cigarette use and its effect on the cardiovascular function.
They recruited two groups of participants for the study, one group of smokers and one group of ex-smokers who’d completely switched to vaping. They took measurements of heart function, then asked the group of smokers to smoke one cigarette and the vapers to vape for seven minutes. After this, they took another set of measurements. After smoking a cigarette, there was an increase in both systolic and diastolic blood pressure (the top and bottom numbers in a blood pressure reading, respectively), whereas the vapers only showed a slight elevation is diastolic blood pressure. For the heart function measurements, smoking impaired function in one area of the heart, whereas vaping had no effects.
This study was presented at a conference originally, and the group had a similar piece of research published in BMC Cardiovascular Disorders in 2014.
2. E-cigarettes Emit Very High Formaldehyde Levels Only In Conditions That Are Aversive to Users: A Replication Study Under Verified Realistic Use Condition
Konstantinos E. Farsalinos, Vassilis Voudris, Alketa Spyrou and Konstantinos Poulas
The New England Journal of Medicine formaldehyde study is one of the most well-known pieces of research into e-cigarettes, and led to many headlines warning about the dangers of formaldehyde in e-cigarette vapour. However, the research was immediately criticized by vapers for the unrealistic vaping conditions used in the test. The authors tested a low-quality atomizer at a much higher voltage setting than it was capable of being used at.
The criticisms were initially brushed aside, but they gained a lot more traction when Dr. Farsalinos and his team published a study which confirmed that the atomizer’s wicking ability is central to the settings it can be used at and the formaldehyde production.
But the study that makes the list is a direct replication of the NEJM research, which Dr. Farsalinos and colleagues had published in 2017. The researchers got the exact same equipment as they used in the original study, and used the same puffing schedule from the study too. The key additional step was recruiting 26 experienced vapers to test out the protocol before looking at what was in the vapour. The vapers tried 5 to 7 puffs at increasing voltages (with a short break between each session) and were told to identify when they detected the awful taste that signifies a “dry puff.” The vast majority of vapers said they got dry puffs at 4.2 V or lower, while the remaining three said they got dry puffs at 4.4 V.
The results show that levels of formaldehyde in vapour increase drastically in dry puff scenarios. Even at the upper end of realistic use – and using “worst case” assumptions like the authors of the NEJM study did – the researchers calculated that a day of vaping would reduce your formaldehyde exposure by 32% compared to a pack-a-day smoker. In a nutshell, the study showed that the NEJM paper’s results were completely irrelevant to real-world use, because of the dry puff effect.
3. Carbonyl Emissions in E-cigarette Aerosol: A Systematic Review and Methodological Considerations
Konstantinos E. Farsalinos and Gene Gillman
The formaldehyde issue made such a big fuss in the media and Dr. Farsalinos and his team’s subsequent research put it all into context so well that in early 2018, the time was right for a complete summary of what we know so far. The systematic review from Dr. Farsalinos and Gene Gillman does just that, looking over 32 studies and drawing attention to the problems with the methods the researchers used.
Not only were the methods and results inconsistent, but many of them also fall prey to the dry puff issue and therefore have little to no relevance to vapers in the real world. As well as drawing attention to the replication studies published by Dr. Farsalinos and his team, the paper goes through some advice – which is admittedly fairly basic to anybody familiar with vaping – to ensure dry puffs aren’t an issue in future research. The simplest advice is to have vapers test the protocol to validate it prior to conducting a study, but only four out of the 32 studies covered actually did it.
This systematic review is the ideal rebuttal to concerns about formaldehyde, acetaldehyde, acrolein and other similar chemicals in e-cigarette vapour, especially combined with the direct replication of the NEJM study above.
4. Can e-Cigarettes and Pharmaceutical Aids Increase Smoking Cessation and Reduce Cigarette Consumption? Findings from a Nationally Representative Cohort of American Smokers.
Benmarhnia, T., Pierce, J.P., Leas, E., White, M. M., Strong D.R., Noble, M. L. and Trinidad, D.R.
One of the main issues in the vaping debate is whether e-cigarettes are effective for helping smokers quit, and if so, how effective they are. Many studies have attempted to address this question, but several of them use less-than-ideal methods and don’t really add anything of value to what we know.
However, this US-based study examined over 3,000 quit attempts from smokers involved in the US Population Assessment of Tobacco and Health (PATH) study from 2013 to 2015. They looked at the influence of pharmaceutical quit smoking aids and e-cigarettes on persistent abstinence from cigarettes (defined as 30 days or more of not smoking). They even matched the participants on how difficult it was likely to be for them to quit, to ensure that the people included in different groups were fairly comparable.
Firstly, the results showed that vaping was the most popular quit-smoking aid – used by just over a quarter of smokers who tried to quit. More importantly, though, participants who vaped were much more likely to have quit smoking by the end of the study. Although they’re the most widely recommended quitting aids by professionals, pharmaceutical approaches (including Chantix, Wellbutrin/Zyban and patches/gums) did not significantly improve quitting rates. In short, vaping worked for the smokers but medications and nicotine replacement therapies didn’t help at all.
5. Peering Through the Mist: Systematic Review of What the Chemistry of Contaminants in Electronic Cigarettes Tells Us About Health Risks
Published in January 2014, this study by Igor Burstyn looks at the effects of the chemicals in electronic cigarettes and whether or not we (or bystanders) should be concerned overexposures to vapour As with all chemicals of any kind, the study recommends monitoring the general health of those exposed to the chemicals in e-cigs while keeping any negative effects as small as possible.
Burstyn looked through peer-reviewed and “grey” literature on the chemicals in vapor, and compared the detected levels to Threshold Limit Values, which are the most universally recognised workplace exposure limits. The investigation found that the vast majority of predicted daily exposures were well below 1% of the values permissible in the workplace, with exposure to acrolein and formaldehyde were below 5% of their limits. The only chemicals vapers are likely to be exposed to in potentially concerning amounts – based on the admittedly precautionary workplace limits – are the declared ingredients PG and VG.
Burstyn also highlights that exposure to bystanders is likely to be “orders of magnitude less” than direct vapour stream.
In short, the study shows that there is little for vapers to be concerned about when it comes to the chemicals in vapour.
6. Nicotine Without smoke: Tobacco Harm Reduction
Royal College of Physicians
The Royal College of Physicians’ report into e-cigarettes is one of the most well-known and widely-cited reviews of the evidence on e-cigarette. The report is huge but is absolutely chock-full of useful information about smoking in Britain, nicotine, current tobacco control efforts, non-tobacco nicotine products, and e-cigarettes.
Reading the whole thing is a big undertaking, but the basic conclusions drawn from the research conducted up to 2016 release of the report are very positive about the harm reduction potential of vaping.
The report states that e-cigarettes appear to be effective when used to quit smoking and that concerns about “renormalization” of smoking or gateway effects from vaping are overblown, given that they are overwhelmingly being used by existing smokers looking for a way to reduce harm to themselves.
On the point of harm, the report states that they are likely to be more dangerous to users than nicotine patches and gums, but that the risks from long-term vaping are unlikely to exceed 5% of the risks from smoking.
The summary of the report concludes:
“in the interests of public health, it is important to promote the use of e-cigarettes, NRT, and other non-tobacco nicotine products as widely as possible as a substitute for smoking in the UK.”
7. Electronic Cigarettes for Smoking Cessation
Jamie Hartmann‐Boyce, Hayden McRobbie, Chris Bullen, Rachna Begh, Lindsay F Stead and Peter Hajek
Cochrane reviews are widely-respected systematic reviews of all of the evidence on a particular topic, and their look at the safety and effectiveness of e-cigarettes for quitting smoking, therefore, carries a lot of weight.
The researchers looked at randomised controlled trials and other studies that measured abstinence from smoking after a period of six months or longer. They found two eligible randomized controlled trials and 21 cohort studies for their analysis.
The researchers concluded that the two trials show that e-cigarettes help smokers quit long-term in comparison to placebo (i.e. nicotine-free) e-cigarettes. Additionally, one study comparing e-cigarettes to nicotine patches found no difference in success rates.
The evidence is graded “low” by quality standards because of a small number of trials and few participants, meaning that the results presently involve a lot of uncertainty. However, these studies were reliably conducted, and while lower quality, the cohort studies supported this result too.
No studies detected serious health effects from vaping for up to two years, and the authors note that there are 15 randomized controlled trials in progress which would be eligible for such a review in future.
8. E-Cigarettes: Methodological and Ideological Issues and Research Priorities
Professor Etter looks at the methodology and ideological issues present in current research. Methods of testing need to change as quickly as technology does when it comes to e-cigs.
Many vapers are aware that our current devices will be “outdated” in several months, and Etter stresses that long-term studies are important but it must be understood they will be outdated by the time they are published. In order to combat this, research must be done effectively and quickly.
Etter points out that failure to acknowledge that e-cigs only need to be safer than traditional cigarettes, and not completely safe, creates a negative attitude towards products that reduce the risks of smoking. The emphasis on negatives of e-cigs by public health, media and tobacco control does not always reflect the actual findings of the research conducted.
In conclusion, he calls on regulators to take into account the inadvertent consequences of excessive regulation.
9. An Assessment of Indoor Air Quality Before, During and After Unrestricted Use of E-Cigarettes in a Small Room
Grant O’Connell, Stéphane Colard, Xavier Cahours and John D. Pritchard
One of the main issues for the public discussion of the potential benefits and risks of e-cigarettes is how much risk – if any – they pose to bystanders in the room with someone who is vaping. This study aimed to answer this question, recruiting five vapers (three regular vapers and two non-vapers) to two vape for almost three hours in a room just less than 40 cubic meters in volume. They analyzed the air in the room before, during and after the vaping session.
The authors looked for nicotine, PG, VG, polycyclic aromatic hydrocarbons, carbonyls (like formaldehyde), metals and tobacco-specific nitrosamines. The researchers found no significant changes in the levels of most of the chemicals, with the exception of PG – which decreased rapidly after the session. They also detected a small increase in carbonyl levels, but these remained well within indoor air quality guideline levels. The authors concluded:
“[A]ny additional chemicals present in indoor air from the exhaled e-cigarette aerosol, are unlikely to present an air quality issue to bystanders at the levels measured.”
The study was published in the International Journal of Environmental Research and Public Health, but the authors were employees of Imperial Tobacco Group/Fontem Ventures.
10. Effect of Smoking Abstinence and Reduction in Asthmatic Smokers Switching to Electronic Cigarettes: Evidence for Harm Reversal
Riccardo Polosa, Jaymin Morjaria, Pasquale Caponnetto, Massimo Caruso, Simona Strano, Eliana Battaglia and Cristina Russo
Asthma affects a large proportion of the population and is further exacerbated by smoking or being around smokers. This study shows that by using an e-cig, asthma sufferers can reduce their cigarette use, which in turn will help reduce asthma-related complications.
The researchers looked at lung function using spirometry tests, which include things like the amount of air you can exhale after taking the deepest breath you can. In addition, they conducted tests of airway hyper-responsiveness, which is the characteristic issue for people with asthma. They also evaluated their condition based on an asthma control questionnaire and the number of times their condition worsened (and required short term additional treatment) over the period of the study. The study took baseline measurements before the asthmatics switched to vaping, and then followed up 6 and 12 months later.
The results show that lung functioning, asthma control and airway hyper-responsiveness were improved in both the participants who switched completely to vaping and the ones who became dual users. There were also reductions in the number of exacerbations, but these differences weren’t statistically significant. Overall, the study suggests that switching to vaping leads to improvements in asthmatics’ condition.
Positive results from this study lead the researchers to recommend large controlled trials to further confirm their observations.
11. Are Metals Emitted from Electronic Cigarettes a Reason for Health Concern? A Risk-Assessment Analysis of Currently Available Literature
Konstantinos E. Farsalinos , Vassilis Voudris and Konstantinos Poulas
One of the most common arguments against e-cigarette is that the vapour contains dangerous chemicals, and metals are one of the most commonly-cited concerns. However, the presence of a potentially dangerous chemical isn’t a sign of risk on its own, because the dose makes the poison – i.e. the amount of the substance is absolutely crucial to work out the risk.
This paper from Dr. Farsalinos and colleagues looks at the evidence on metals in e-cigarette vapor, with a specific focus on performing a risk assessment. The researchers used standards established for inhalable medicines from the US Pharmacopeia, workplace limits established by the National Institute of Occupational Safety and Health (NIOSH) and one from the Agency for Toxic Substances and Disease Registry. They based their assessment on an extreme case of 1,200 puffs per day – twice as many as most vapers will take.
The results show that the exposure to most metals is way below the limit for inhalable medicines, with the exception of cadmium in just one out of the 13 products tested, which exceeded the limit by 10%. All of the products were far below the limits established by the other two regulatory bodies, even with the extreme assumptions used for the amount of vaping each day.
The researchers concluded:
“Based on currently available data, overall exposure to metals from EC use is not expected to be of significant health concern for smokers switching to EC use, but is an unnecessary source of exposure for never-smokers.”
In other words, if you’re a smoker, you’re much better off vaping, but if you’re a non-smoker, you’re better off staying that way!
12. Young People’s Use of E-Cigarettes Across the United Kingdom: Findings from Five Surveys 2015–2017
Linda Bauld, Anne Marie MacKintosh, Brian Eastwood, Allison Ford, Graham Moore, Martin Dockrell, Deborah Arnott, Hazel Cheeseman and Ann McNeill
The issue of vaping among young people is one that people opposed to e-cigarettes constantly mention. Vaping may be safer than smoking, they concede, but it’s creating untold problems among youth, getting young people addicted to nicotine and possibly causing them to start smoking. This study looks at data from five UK surveys conducted between 2015 and 2017 to see the extent of youth vaping, including two surveys from ASH, schools surveys from Wales and Scotland, and the Youth Tobacco Policy Survey.
The results are very reassuring for anybody concerned about the impact of the rise of vaping on Britain’s youth. In 2015 and 2016, between 11 and 20% of 11 to 16-year-olds had ever smoked, with regular smoking at between 1 and 4%. For vaping, 7 to 18% of youth had ever tried it, and 1 to 3% vaped regularly.
The big concern is vaping among never-smokers, but the results show that between 4 and 10% had ever tried vaping and just between 0.1 and 0.5% vaped regularly. In contrast, 67 to 92% of regular smokers had tried vaping and between 7 and 38% of them vaped regularly. The picture is simple: most vaping among youths is experimental, and regular use is almost entirely confined to youth who currently or previously smoked.
People critical of vaping might point out that this study only applies to the UK, and so you can’t use the results to allay fears about youth vaping in the US or Australia, for example. However, the UK has a relatively permissive stance towards vaping compared to most other countries. Because of this, you’d expect that if vaping was going to cause a problem among youth, it would be most likely to be happening in the UK.
13. Patterns of Flavored E-Cigarette Use Among Adult Vapers in the United States: An Internet Survey
Konstantinos Farsalinos, Christopher Russell, George Lagoumintzis and Konstantinos Poulas
Dr. Farsalinos, Christopher Russell and colleagues submitted this study directly to the FDA in response to their call for public comment on the issue of flavours in tobacco products. The survey covers almost 70,000 adult vapers in the US, and it was conducted in April 2018. The survey was promoted by major e-cigarette advocacy groups, so most of the responses were from dedicated vapers. Notably, though, around 5% of the respondents were never-smokers, while most were former smokers.
The researchers broke the results down by smoking status – current, former and never-smokers – but it made effectively no difference to the overall result: fruits, desserts and candies were the three most popular classes of e-cigarette flavour, in that order. This was true regardless of smoking status, and both when the vapers first started and now. The standard narrative is that sweet flavours are intended to attract non-smokers and youths to vaping. However,, but this result clearly shows that in the US, all adult vapers prefer these flavours, including the 74.6% of respondents who were vaping at the time they quit smoking.
In a nutshell, this study shows that a flavour ban would primarily affect adults intending to or likely to quit smoking by vaping.
14. The Impact of Flavor Descriptors on Nonsmoking Teens’ and Adult Smokers’ Interest in Electronic Cigarettes
Saul Shiffman, PhD, Mark A. Sembower, MS, Janine L. Pillitteri, PhD, Karen K. Gerlach, PhD, MPH and Joseph G. Gitchell, BA
Vapers know that flavours play a big part in our vaping journey, as shown by the previous study. We also know that we are constantly under the scrutiny of those who imply manufacturers are marketing to children with candy or sweet flavours.
This study came before the previous one, but addresses the key concern of anti-vaping campaigners more directly. It shows that non-smoking teens were less attracted to flavours than adult smokers. Interest among both groups was relatively low, but in the adult smoker group, interest was greatly affected by the presence of e-liquid flavours.
In contrast, while interest in vaping didn’t vary by flavour among the non-smoking teens, if anything, single malt scotch e-liquid was the flavour they were most interested in, not bubblegum or others commonly highlighted as part of anti-vaping campaigns.
15. Effectiveness of the Electronic Cigarette: An Eight-Week Flemish Study with Six-Month Follow-up on Smoking Reduction, Craving and Experienced Benefits and Complaints
Karolien Adriaens, Dinska Van Gucht, Paul Declerck and Frank Baeyens
This study tested a range of determining factors in the process of cessation over a period of 8 weeks, using two groups of e-cig users and a control group. It showed that second generation e-cigs (not cigalikes) were very effective reducing cigarette cravings and withdrawal symptoms. with nearly half of the participants completely abstaining from traditional tobacco for at least 6 months after the lab sessions.
The study had a unique design, with the two e-cig user groups vaping from the beginning of the two months of lab sessions, then the control group being given an e-cig to use after the end of the lab sessions. After the lab sessions, none of the control group had quit smoking but 34% of the vapers had. Three months later, 38% of the original control group (who were now vaping too) and 37% of the original groups of vapers were abstinent from smoking. At the end of the study, 21% of the whole group had stopped smoking completely, and overall, the group were smoking 60% fewer cigarettes per day than at the beginning of the study.
As with all smaller studies, the researchers encourage large scale trials to confirm their results.
16. Health Impact of E-Cigarettes: A Prospective 3.5-Year Study of Regular Daily Users Who Have Never Smoked
Riccardo Polosa, Fabio Cibella, Pasquale Caponnetto, Marilena Maglia, Umberto Prosperini, Cristina Russo and Donald Tashkin
Arguably the most commonly-heard refrain from people opposed to e-cigarettes is “we just don’t know enough to estimate the risks yet.” The big problem with this statement is that it’s often used as a way to ignore all of the things that we do know, but it is of course true that there hasn’t been much time to conduct long-term studies of the effects of vaping yet. However, this study from Professor Riccardo Polosa and colleagues offers some crucial evidence of exactly the type we need.
The researchers followed 9 daily vapers who had never smoked a cigarette for three and a half years, and compared them with a group of 12 never-smokers who didn’t vape. They looked at their blood pressure, heart rate, body weight, lung function, breathing symptoms, exhaled nitric oxide (which is a measure of airway inflammation) and carbon monoxide, as well as a high resolution scan of the lungs.
The study found absolutely nothing to suggest that the 3.5 years of vaping affected the never-smokers’ health, by comparing both their baseline measurements to their follow-up measurements and comparing their results to the control group results.
The researchers conclude:
“Although it cannot be excluded that some harm may occur at later stages, this study did not demonstrate any health concerns associated with long-term use of [e-cigarettes] in relatively young users who did not also smoke tobacco.”
17. Stigma and the Ethics of Public Health: Not Can We but Should We?
Smoking, Stigma and Tobacco ‘Denormalization’: Further Reflections on the Use of Stigma as a Public Health Tool. A commentary on Social Science & Medicine’s Stigma, Prejudice, Discrimination and Health Special Issue
Bell K., Salmon A., Bowers M., Bell J. and McCullough L.
While these studies, published in PubMed back in 2008 and 2010, are not about vaping, all us vapers were smokers at some point in our lives. In the world of vaping advocacy it is important to remember not to stigmatize smokers for their choice to smoke or lack of willingness to quit.
By demonizing smokers (or vapers) we run the risk of discouraging people from making well-informed choices about their health and those around them. Public health officials should also remain unbiased and refrain from judgmental behaviour. Remaining positive and encouraging, while providing good information, will help smokers make the switch to vaping.
There’s a further reason to be cautious around the messages we send to smokers. A study by advertising guru Martin Lindstrom found that graphic anti-smoking ads can activate the very part of the brain that stimulates desire for nicotine. Our very attempts to persuade smokers to quit could be having the opposite effect!
18. Smoking in England, the Smoking Toolkit Study
Smoking in England
The Smoking Toolkit Study is an important source of information that every vaper should follow. They have been collecting data since 2006, so far totalling over 240,000 responses from smokers and ex-smokers. The most recent results from July 2018 show that smoking has declined from 24.2% in 2007 to 17.5% in 2018, with the success rate for people who tried to quit having increased over the same period.
Vaping has remained relatively stable since 2013, but the number of long-term ex-smokers who vape has increased over the same time period. This strongly suggests that people are successfully quitting smoking by starting to vape.
However, the use of e-cigs among recent ex-smokers has declined slightly after a peak in late 2016. At the same time, vaping among never-smokers has been consistently low, and comparable to the use of NRT (like patches and gums) by never-smokers.
Although “dual use” is common in both NRT users and vapers, it is more likely that people using NRT will also smoke. Additionally, the number of people aged 16 to 24 who’ve ever smoked has declined slightly since 2011, countering claims that vaping will “renormalise” smoking.
This data is promising for smokers that are looking to reduce harm, and shows that e-cigs are a viable and popular option. It also goes a long way to counter arguments that e-cigarettes don’t help smokers stop using tobacco cigarettes.
19. Use of Electronic Cigarettes (Vapourisers) Among Adults in Great Britain
Action on Smoking and Health
May 2017 brought even more promising data from ASH. They estimated that 2.9 million adults in Britain currently vape, an increase from 700,000 the time of their first survey in 2012. The 2017 survey is the first time there were more ex-smokers who vape than current smokers, with 52% of users being ex-smokers (1.5 million) compared to 45% being current smokers (1.3 million). Ex-smokers report vaping to quit, while most smokers say they’re vaping to reduce the amount they smoke.
The survey also shows that people who vape every day are more likely to have quit smoking than people who vape less frequently. If they do still smoke, people who vape every day have fewer cigarettes per day on average than less frequent vapers.
Unfortunately the study also shows that only 13% of the public correctly respond that e-cigarettes are “a lot less harmful” than smoking, with an additional 30% saying they’re just “less harmful.” This situation has also being getting progressively worse since 2013.
The survey also has some interesting data on the reasons people vape, the reasons people stop vaping and the reasons non-vaping smokers have never tried it, as well as some data on the types of e-cigarettes used and vapers’ preferred flavours.
20. Nicotine Levels and Presence of Selected Tobacco-Derived Toxins in Tobacco Flavoured Electronic Cigarette Refill Liquids
Konstantinos E. Farsalinos, I. Gene Gillman, Matt S. Melvin, Amelia R. Paolantonio, Wendy J. Gardow, Kathy E. Humphries, Sherri E. Brown, Konstantinos Poulas and Vassilis Voudris
Dr Farsalinos and his team tested 21 samples of e-liquid and compared chemicals found in them to those found in tobacco products. While his study confirms that e-liquids are not free from potentially harmful chemicals, similar to those found in tobacco products, and that e-liquids containing naturally extracted tobacco could result in higher exposures, e-liquids still contained much lower levels of TSNAs and nitrates, making them less harmful than tobacco products.
This study is very promising in determining the level of risk vapers are faced with compared to smoking, but further studies would need to be conducted to continually verify what we all have known for years now – electronic cigarettes are much less harmful than smoking.
21 New: Electronic cigarette use and harm reversal: emerging evidence in the lung
We had to update this article with the latest study from Professor Polosa, who found that switching to e-cigs from cigarette could lead to improvements in lung problems caused by smoking. 65.4% of people with asthma and 75.7% of people with COPD reported an improvement in symptoms, with over 18% no longer needing any medicine.
Polosa went on to write:
…the emerging evidence that EC use can reverse harm from tobacco smoking should be taken into consideration by regulatory authorities seeking to adopt proportional measures for the e-vapor category.
One of the most frustrating claims we have heard (repeatedly!) over the years is:
“We just don’t know if e-cigs are safe.”
Yet the studies here are just a small fraction of the total studies carried out into e-cigarettes. And while e-cigarette may not be ‘safe,’ the studies do show that they are far ‘safer’ than tobacco cigarettes. In fact, the consensus amongst e-cig researchers is that they are at least 95% safer than tobacco cigarettes.
So next time you hear a wild accusation about electronic cigarettes, try pointing them towards a study that counters that claim!