Spreading fear and confusion with misleading formaldehyde studies
Another alarmist and deeply misleading story about formaldehyde and e-cigarettes has now emerged in the New England Journal of Medicine: Hidden Formaldehyde in E-cigarette Aerosols. I have written to the corresponding authors, and I would like to share my open letter.
Hidden Formaldehyde in E-cigarette Aerosols – some questions and concerns
21 January 2015
Dear Dr Peyton, Dr Pankow
I write with reference to the forthcoming letter “Hidden Formaldehyde in E-cigarette Aerosols” to be published in the New England Journal of Medicine, under a 5pm EST 21 January 2015 embargo.
Given the great potential for these findings and the related cancer-risk calculations to cause damaging confusion and fear among smokers and vapers, I would be grateful if you could clarify the following:
1. What care was taken to ensure that the puff regime used was a reasonable proxy for human use and exposure? The letter does not detail any attempt to calibrate the puffing regime used in the experiment to match real-world vaping behaviour. The levels of formaldehyde detected suggest it was a highly unrealistic regime.
2. What, if any, precautions were taken to avoid measuring and reporting on ‘dry puff’ conditions – i.e. through use of such high voltage and high intensity puffing that the coil becomes so hot that it creates vapour of such acrid taste and harshness that human users would not use it in that way? It is under these conditions that high levels of formaldehyde and related compounds would be expected to form – but no human would ever be exposed to them. Humans have control over the sensory experience that puffing machines do not.
3. In making your newsworthy claims about cancer risk, what confidence do have that the puffing regime used appropriately represents human vaping behaviour, and therefore human cancer risk? There is a danger that naive reporting of your findings will characterise these risks as integral tovaping products, whereas they are a feature of the operating regime, which appears to be extreme in this case. These findings are only appropriate as cancer risk communication if the operating regime is realistic. However, the letter does not detail how you have assured this is the case – and no caveat has been provided to highlight that serious and probably fatal weakness in this work.
4. In the calculations of cancer risk, it is assumed that “inhaling formaldehyde-releasing agents carries the same risk per unit of formaldehyde as the risk associated with inhaling gaseous formaldehyde“. Can you provide a citation to support this assumption, given that the attention-grabbing findings in the letter rest entirely on it? As you will be aware, formaldehyde-releasing preservatives are used as an alternative to formaldehyde in many preparations for safety reasons.
5. The letter claims that the incremental lifetime cancer risk associated with long term vaping “is 5 times as high … or even 15 times as high … as the risk associated with long-term smoking“. Can you clarify that this comparison refers to only that part of the smoking cancer risk that arises from formaldehyde exposure? In order not to confuse readers with the idea that long term vaping may carry 5-15 times the risk of smoking, would it be possible to provide an appropriate context: for example, what proportion of the smoking cancer risk is attributable to formaldehyde? I think it is a small fraction of the total, and it would have been prudent to state this. Formaldehyde is not the most important carcinogen in cigarette smoke by some distance and just one of many. TheSurgeon General’s 2010 report Chapter 5 provides a useful guide, but does not go as far as your letter does in attributing cancer risk to individual carcinogens. The Surgeon General also reminds us that:
Aldehydes such as formaldehyde and acetaldehyde occur widely in the human environment and are endogenous metabolites found in human blood
It is possible therefore that the estimation of cancer risk from formaldehyde is more complicated than your simple model allows for.
To be more direct, I am concerned that:
- This study uses a completely unrealistic puffing regime to create the conditions in which formaldehyde forms with no attempt to calibrate the machine to reflect realistic human use.
- That it presents results from extreme and unrealistic operating conditions which are them built into a ‘back of the envelope’ calculation of cancer risk.
- That this contrived and artificial cancer risk is misleadingly compared to real human cancer risks associated with smoking.
- That the statements about vaping having 5-15 times the incremental cancer risk associated with smoking are provided without context and could easily be misread as implying that vaping is more dangerous than smoking. It would not be the first time that misreporting of formaldehyde findings have created this impression.
- This study may repeat the harm done through mischaracterisation of ‘light’ cigarettes by use of unrealistic puffing regimes that did not reflect real human behaviour. The same is likely to apply here, but instead of understating risk of a harmful product, the effect will be to grossly overstate the risk of a relatively benign product – with equally damaging results.
Many smokers have a great opportunity to switch from smoking to vaping, and to reduce their incremental risk of disease by 95-99%. However, studies like this and the reporting that has followed, are gradually persuading smokers that e-cigarettes are much more risky than they are, and that they might as well continue to smoke. A study published in 2014 found the following:
In 2010, 84.7% of smokers surveyed believed e-cigarettes were less harmful than traditional cigarettes, but according to this new study in 2013, that number dropped to just 65% [link].
This is a trend that should shame the public health community and the academics that are fuelling consumers’ misunderstanding with misleading studies that misrepresent risk. I am sure it is not your aim to protect the cigarette trade and prolong the epidemic of smoking related disease, but it may well be the effect.
I hope you will take great care to ensure your findings are described in context and with appropriate caveats about whether these results are realistic for human exposure and that the calculations of cancer risk are remotely meaningful..
London / Harare
[No competing interests]
Update: these two wrote about e-cigarettes in November 2014 Chemists break down e-cigarette research and haplessly demonstrated that they are basically clueless:
Peyton agreed with Pankow. He also pointed out that the high temperatures to which the element heated e-cigarette additives—over 600 degrees celsius—resulted in the creation of molecules not previously seen.
Vaping is typically done at 200-260 degrees celsius, with dry puff conditions developing at around 280 degrees.
Excellent new commentary is in from:
- Konstantinos Farsalinos: The deception of measuring formaldehyde in e-cigarette aerosol: the difference between laboratory measurements and true exposure
- Mike Siegel: New Study Reports High Levels of Formaldehyde in Electronic Cigarette Aerosols
- Norbert Zillatron: Freaking Formaldehyde
- Professor Peter Hajek: Formaldehyde in E-cigarettes: expert responds
And of course, there was the predictable ‘send in the clowns’ response from tobacco control…
The Japanese Formaldehyde Fiasco
Also, it is worth mentioning that this is not the first time an overhyped formaldehyde story has made its way into print rather than the bin. Excellent blogs by Konstantinos Farsalinos [Electronic cigarette aerosol contains 6 times LESS formaldehyde than tobacco cigarette smoke] and Brad Rodu [Formaldehype vs. Fact: Levels Are Far Lower in E-Cigarettes Than In Cigarettes] give the full story of the Japanese rogue result that made headlines worldwide. At the time, I also wrote to the author of this study, Dr. Naoki Kunugita, to point out the irresponsibility of his statements. Here is the letter from November 2014.
Date: 29 November 2014 at 14:31
To: “Dr. Naoki Kunugita M.D. Dr.Med.Sci.” <email@example.com>
Dear Dr Kunugita
I hope you are aware of the impact that your comments on e-cigarette formaldehyde exposure has caused in the press, and therefore in public perception of risk of e-cigarettes relative to smoking. You can read some of it here: http://goo.gl/1rOyDu
The impression that has been left is exactly the opposite of a realistic appraisal of exposure to carcinogens in general and formaldehyde in particular that a responsible authority would wish to communicate to the public. Your remarks appear to be based on a single unpublished measurement: “In one brand of e-cigarette the team found more than 10 times the level of carcinogens contained in one regular cigarette” as quoted by AFP. Can you provide the data that supports this argument? I have been unable to locate it in the published literature.
A more realistic appraisal across the range of measurements would suggest formaldehyde exposures far lower than for smoking – at least six times lower based on your own data and perhaps fifty times lower would be an appropriate characterisation. I hope you have seen the critique of your work and communication by Dr Konstantinos Farsalinos (here)
However, you have chosen to communicate an extreme result that is not open to scrutiny. Because it is not published or replicable, we cannot know for sure: but is likely that this device was running very hot and/or dry to generate emissions like this. No human user would continue with this mode of operation as the taste would provide immediate feedback to behaviour (something that does not happen with machines). It follows that the result (even if accurate) you have communicated to the public is:
1. an artefact of the machine testing regime and device settings;
2. not a realistic risk for human exposure.
Whether or not it was the aim of your communication, the effect has been to cast doubt in the minds of many smokers about the benefits of switching to e-cigarettes, which would be immensely positive to their health. The perception of risk arising from e-cigarette use is already hugely exaggerated by the public and this will make the misalignment of perception and reality even it worse.
It is not sufficient to argue that your statement was technically correct (yes, you may have a result like this). It is essential that when respected institutions and experts make comments they take care to ensure the effect it has on perception is balanced and proportional, does not spread false alarm and helps people understand the risks rather than mislead them. You have a responsibility to be both truthful and to ensure you work is placed properly in context.
Given this has not happened with this statement, I am writing to ask you to make a proper balancing statement that would put this in context and restore some reality to the discussion of e-cigarette risks.
I hope to hear from you soon and that you will take this request seriously – I am sure you do not want to be responsible for supporting continued cigarette use by confusing people about e-cigarette risk.
Disclosure: I am a long standing supporter of harm reduction techniques for reducing tobacco related disease. I have no competing interests. For further reading please see my publication:WHO Position on ENDS (e-cigarettes): a critique of the use of science and risk communication