E-cigarette vapour could damage health of non-smokers
BMJ 2014; 349 doi: https://doi.org/10.1136/bmj.g6882 (Published 17 November 2014) Cite this as: BMJ 2014;349:g6882
All rapid responses
Rapid responses are electronic comments to the editor. They enable our users to debate issues raised in articles published on bmj.com. A rapid response is first posted online. If you need the URL (web address) of an individual response, simply click on the response headline and copy the URL from the browser window. A proportion of responses will, after editing, be published online and in the print journal as letters, which are indexed in PubMed. Rapid responses are not indexed in PubMed and they are not journal articles. The BMJ reserves the right to remove responses which are being wilfully misrepresented as published articles or when it is brought to our attention that a response spreads misinformation.
From March 2022, the word limit for rapid responses will be 600 words not including references and author details. We will no longer post responses that exceed this limit.
The word limit for letters selected from posted responses remains 300 words.
I have no wish to comment on any declared or undeclared interests. However, the reply to our response by Torjesen perpetuates and reinforces the errors in the original article. Her article did indeed report that our results “provide evidence for a possible exposure risk to passive smokers in enclosed spaces with limited ventilation if all the emissions from e-cigarettes were exhaled”, but went very much further in asserting a health risk. A risk, or probability, of exposure to something does not imply a health risk. It is not necessary to be a scientist to know that there is a potential exposure; a visible mist is exhaled by e-cigarette users (or vapers). Our study was simply concerned with quantification of this exposure, not its effects on health.
Consider an alternative situation with a high likelihood of exposure but low risk to health. An onlooker accidentally stumbles on a nudist beach. They may not approve of the exposure and may take a particular moral standpoint on it. However, it is unlikely that their health will be compromised. Similarly, without a causal link between the exposure to the liquid droplets produced in e-cigarette mist and adverse health consequences, there should be no conflation of exposure risk and health risk. It is possible to object to an exposure on moral grounds, but not on the basis of current scientific evidence for a health risk. Similar objections may be raised to exposure to strong perfumes, air fresheners or indeed bodily odours. No study has demonstrated any health risk at any exposure to e-cigarette mist particles and certainly not at levels anywhere near as low as those found in our study (and these were likely orders of magnitude higher than normal levels). Indeed, as reaffirmed at the summit, all previous studies of secondhand exposure have consistently confirmed the absence of toxins from the environment of second-hand exposure. Thus, there is no substantiation that there is any risk to bystanders. Unlike the acknowledged linkages between the combustion derived smoke particles from cigarettes and health, there is simply no evidence for a health risk. Our data only support a potential exposure.
As Torjesen indicates, it is important that emerging data such as those from our study are reported. However, they must not be appropriated for a particular purpose, nor used to support conjecture that they cannot. The preliminary nature of our data is such that they cannot be used to "ensure that we do not put the health of non-smokers at risk through passive exposure to e-cigarette vapour while trying to reduce the risks for “smokers” trying to quit cigarettes or follow a harm reduction approach". Further studies investigating the relationship between exposure to e-cigarette mist and possible health risks are required before any assertion can be made.
As detailed in our original response, we must request retraction of inaccuracies in the original article. In particular, our study did not find that "particles in secondhand vapour from e-cigarettes have the potential to damage the health of non-smokers" as reported in the opening statement.
Finally, one disturbing non-sequitur in Torjesen's reply belies a misunderstanding of evidence-based policy. She states "The discussion panel (including the researchers) was asked to guess at the magnitude of this risk and the consensus was that it would be one twentieth of the risk of cigarettes or less, indicating that these devices are not risk free." Evidence-based conclusion is not based on guesswork and there can therefore be no indication that the devices are "not risk free" on this basis; it only indicates an upper limit to the health risk as guessed by the panel in the absence of evidence for any risk. Furthermore, I explicitly stated during the panel discussion that I was unqualified even to make a guess at the health risk, but would guess at the exposure risk.
Competing interests: No competing interests
I am the editor of a magazine called The Advisor, which is owned by a company called ADED Media, and goes to people working in stop smoking services. McNeil Products Ltd provide an educational grant to support the production and distribution of the magazine in return for a certain number of advertisement spaces. As the cover of the magazine clearly states, McNeil Products Ltd has no input into its editorial content.
The content of the magazine is decided by me. As far as I am aware, I have never met with, spoken with or communicated in any way with anyone from McNeil Products about The Advisor or anything else.
If I have any competing interests in terms of my editorial direction, they are that I am a supporter of all forms of smoking cessation because of the damage smoking does to smokers, their families and other subjected to it through passive routes. I have also been an advocate of banning smoking in all forms since I was a child, being the child of two parents who were addicted to the habit and died prematurely of smoking-related disease.
Competing interests: I am a freelance health journalist and I am commissioned to do work by a number of different publishing companies
I would like to draw your attention to a matter concerning the counter-response to claims by Professors McFiggans and Harrison that the article, “E-cigarette vapour could damage health of non-smokers,” written by Ingrid Torjesen, in which they assert that the author has seriously misrepresented their research.
At the end of her counter-response, Ms Torjesen states that she has no competing interests. The fact that Ms Torjesen is the editor of The Advisor magazine which covers smoking cessation and is financed by McNeil Products, makers of Nicorette products, leads me to believe that she should have declared this interest. I feel that this is particularly so because the popularity of e-cigarettes is seriously impacting on the profits of the NRT companies, and her connection to the magazine could lead people to believe that her objectivity might have been somehow compromised. Indeed, in his response to her article, Professor McFiggans states, “However there is evidence that the misrepresentation of our work and misappropriation of evidence is more mischievous than simple misunderstanding.”
Footnote: The magazine in question claims to be independent. It may well be editorially independent, but it is financed by a company that advertises their products within the magazine and who stand to profit by making the publication available to smoking cessation health workers. Surely where money is involved, it must be impossible to be totally independent - however hard one strives to be so?
Relevant links:
http://www.bmj.com/content/349/bmj.g6882/rapid-responses
http://www.pharmaceutical-journal.com/ingrid-torjesen/929.bio
http://www.worldcat.org/title/advisor-inspiration-in-smoking-cessation/o...
Competing interests: Full-time user of e-cigarettes and campaigning hobbyist against media scaremongering regarding e-cigarettes!
I was surprised by the comments from Professors McFiggans and Harrison as I believe the article is a fair report of their presentation - “A chamber study of second-hand E-cigarette ‘smoke’ – preliminary results” - as I heard it.
I have no agenda on e-cigarettes. I attended the conference intending to report on the results of the Cochrane review, which the programme indicated would be presented. But in the event these results were not available.
The 15-minute presentation by McFiggans and Harrison was made at the E-cigarette Summit during the ‘Safety and efficacy of e-cigarette’ session, in which there were four presentations. The 30-minute discussion that followed the four-presentations was dominated by discussion of their presentation. Many in the audience, which included representatives of e-cigarette manufacturers and vapers’ organisations, took issue with the results.
During the presentation McFiggans and Harrison said that particles were present in “secondhand e-cigarette smoke” and drew parallels with air pollution, pointing to research that had shown health risks from that. Harrison said: “The most recent epidemiological study from London, which is the study from Richard Atkinson’s group at St George’s in 2010, shows a statistically significant association between the particle number concentration and cardiovascular mortality. That is a statistical association but most people would believe it causal, so these [particles] are a health risk.”
The results suggested that there could be a health implication for non-smokers from the particles in “e-cigarettes smoke”, but the researchers made it clear that this would be far less than the risk from tobacco smoke, as I pointed out in my article. The discussion panel (including the researchers) was asked to guess at the magnitude of this risk and the consensus was that it would be one twentieth of the risk of cigarettes or less, indicating that these devices are not risk free.
However, the WHO has called for a ban on the indoor use of e-cigarettes because of its concerns about the health risks of the vapour. It is therefore important that emerging data, such as those I reported on, are aired to ensure that we do not put the health of non-smokers at risk through passive exposure to e-cigarette vapour while trying to reduce the risks for “smokers” trying to quit cigarettes or follow a harm reduction approach.
The consensus from the e-cigarette summit appeared to be that vapers should not be forced to go outside and stand with cigarette smokers, particularly if they are smokers trying to quit smoking themselves, but that perhaps some limits on where the devices can be used may be necessary.
The article makes it clear that the results were preliminary, but the researchers did say that their results “provide evidence for a possible exposure risk to passive smokers in enclosed spaces with limited ventilation if all the emissions from e-cigarettes were exhaled,” and that is what I reported.
During the presentation and discussion the researchers made it clear that the level of particles in the atmosphere could not be extrapolated from their experiments. I reported that the results were based on a simulation of an e-cigarette user inhaling shallowly. The researchers said that the amount would be less if the e-cigarette user inhaled deeply and more if the wattage of the device was turned up to produce plumes of ‘smoke’. Perhaps I should have included this, but I did not because I thought it unnecessary, not because I set out to misrepresent it.
During the discussion, when asked by Professor Peter Hajek to quantify by how much someone’s exposure to particles would increase if they spent time in a room where e-cigarettes were being used, Harrison replied: “The answer depends critically on how they are using those e-cigarettes. Our experiments simulate a situation where they are not deeply inhaling the aerosol from the e-cigarette; they are blowing it out predominantly into the atmosphere, which I believe is quite a common habit with such things amongst some people. It would be very different if they were deeply inhaling, in which case the vast majority of the aerosol is deposited in their own lungs, but in the situation that we simulated those concentrations are very high and one would have to be exposed for a relatively short period for it to increment quite substantially on the daily total dose of particles. I think an hour’s exposure could easily double the daily exposure of nanoparticles.”
McFiggans added: “The dosage really can’t be extrapolated from our chamber experiments. I might imagine that the levels of particles that are used in our experiments are orders of magnitude higher than the fugitive emissions [emissions of gases or vapours from pressurised equipment] that would be coming out of an e-cigarette. So you might imagine that if the e-cigarettes are being fully inhaled …[and you] were sitting in a room where there weren’t billows of smoke coming out then[ what you inhale as a passive smoker] would be a very much lower contribution to your daily dose than [those in our experiments], but those numbers [in our experiments] were an upper limit and a worst case. Whether it is further down to the lower end, where negligible, or somewhere in the middle of that is dependent on the usage and whether or not they are mods [ more advanced devices used by skilled vapers that produce lots of vapour] and they are changing the wattage and coming out with huge amounts of billowing smoke.”
Competing interests: No competing interests
We read with interest the article "E-cigarette vapour could damage health of non-smokers" by Ingrid Torjesen (BMJ 2014; 349 doi: http://dx.doi.org/10.1136/bmj.g6882). Whilst glad that evidence from aerosol science is finally being acknowledged in the e-cigarette debate, we strongly refute much of the article in tone and emphasis and must demand retraction of certain factually incorrect assertions. There are two inaccuracies in the title "E-cigarette vapour could damage health of non-smokers".
First, we have made no studies of vapours from e-cigarettes, our study made direct measurements of the particles in the visible "mist" from e-cigarettes with no analysis or quantification of the vapours.
Second, we made no statement of the effects on health of non-smokers.
Further, it is stated in the opening paragraph that "Particles in secondhand vapour from e-cigarettes have the potential to damage the health of non-smokers, a study by environmental scientists presented at the e-cigarette summit in London on 13 November has found". We were careful to make no such statement. Rather, we made calculations of loading and inferred exposure, not health risk. The only statement in the presentation with respect to health effects of e-cigarettes was "Health risks are likely to be smaller than those associated with conventional cigarettes". It was stated that "McFiggans explained that, unlike tobacco cigarettes, the material that was inhaled from e-cigarettes was “the same that would come out into the atmosphere.”" This was in the context of the composition of the particles, but it was explicitly stated that this was not in terms of number, size or mass of the particles entering the atmosphere. All these factors must be taken into consideration when evaluating the potential secondhand exposure. Our study is a preliminary study and no firm inferences about particle exposure can be drawn at this stage and certainly none about consequent health effects.
As Torjesen would have been very well aware from the panel debate, the health effects cannot be evaluated from a study such as ours alone. There may have been some elements of misunderstanding on the part of Torjesen. However there is evidence that the misrepresentation of our work and misappropriation of evidence is more mischievous than simple misunderstanding. For example, any reference to the repeated statements in our presentation that the calculations were based on exposures that were likely very much higher than "normal" levels of particulates from e-cigarettes is conveniently omitted as is reference to the extensive panel discussion about the difference in composition between particles from e-cigarettes and traditional cigarettes and its possible relevance to health effects; e-cigarette particles are entirely different in composition and nature to those from urban atmospheric pollutant sources or tobacco cigarette smoke, which are the main emissions evaluated in the context of health effects related to particle size.
We sincerely hope that there was no intention to mislead the debate. We are therefore grateful for the opportunity to clarify our views and to emphasise the pressing need for further research to clarify these and other important issues concerning e-cigarettes.
Competing interests: No competing interests
Re: E-cigarette vapour could damage health of non-smokers
I reported what I heard said at the conference accurately. Since I wrote the article the organisers of the E-Cigarette Summit have posted videos of the presentation and discussion, so I would encourage people to watch them and hear what was said for themselves.
This is the link to the presentation
http://vaping.com/ecigsummit2014/harrison-mcfiggans
And this is the link to the discussion
http://vaping.com/ecigsummit2014/panel-debate-2-hajek-polosa-farsalinos-...
Competing interests: I am a freelance health journalist and I am commissioned to do work by a number of different publishing companies