Inability (or unwillingness) to learn the lesson from our aldehydes study - NEJM paper should be retracted
- Sunday, 24 May 2015 11:42
By Dr Farsalinos
However, it was a big surprise (and disappointment) for me to see the statements by Prof Peyton, a co-author and main investigator responsible for the research letter published in NEJM about formaldehyde in e-cigarette aerosol. The news website Vocativ did an excellent job asking Prof Peyton for his opinion about our study and the results, and this is how every new study on e-cigarettes should be approached.
According to Vocativ, “he (Prof Peyton) wonders how Farsalinos can challenge his conclusions without NMR analyses”. In the press release we specifically stated that: “Our results verify previous observations that it is possible for e-cigarettes to generate high levels of aldehydes”. We found high levels too, and we could easily exceed the levels found by Prof Peyton if we would use 15W in our atomizer setup. Our results and conclusions are IRRELEVANT to the methodology because, irrespective of the methodology used, levels of aldehydes can be extremely high in e-cigarette aerosol as long as you overheat the atomizer and liquid. This is the lesson that everyone should learn.
Prof Peyton mentions: “Using their methods, you’re probably going to miss most of it”. Let me clarify that we used a measurement protocol that has been validated extensively for tobacco cigarettes, while they used a methodology not previously validated, neither for e-cigarettes nor for tobacco cigarettes. If anything, they should be worried about possible methodology issues. I will not comment on the statement that formaldehyde hemiacetals are like lead in paint. I will just repeat what Prof Peyton mentioned in his research letter: “How formaldehyde-releasing agents behave in the respiratory tract is unknown”. He admits that the effect is unknown; in fact, it is not known that formaldehyde-hemiacetal is a formaldehyde releaser during the time it is inhaled. I suppose that if it was, it would have been released to the tube where he collected the aerosol.
The whole discussion about methodologies is misleading. We verified that high levels of aldehydes are produced from e-cigarettes, but at conditions not used by vapers. In fact, it is easy for any scientist to produce as much aldehydes as he wants in the lab. Just take a high-power battery device and overburn the atomizer and liquid. It is the easiest thing you can do.
Prof Peyton discusses about intermediate voltages, which represent realistic use. I am not sure he really understands what realistic use is. If he uses the same atomizer (CE4) at an intermediate voltage (between 3.0V and 5.0V, which were used in the previous study) I can guarantee and predict that he will find very high levels of aldehydes. How do I know that? Simple: I took 10 CE4 atomizers and asked 10 vapers to use them at gradually elevating voltage levels, starting at 3V, taking 4-second puffs (puff duration is also extremely important). Every vaper identified dry puffs at 3.6 volts. So, if Prof Peyton tests the CE4s at 4 volts, he will find high formaldehyde levels. There is no universal definition of "intermediate voltages". For different atomizers there are different power setups that work. For a CE4, there is almost no intermediate voltages. You generate dry puffs very easily, and they have rarely (if ever) been used with power-regulation devices. For other atomizers, they may work at 6-10W, while there are atomizers which need 15W to work and produce vapor. Reading their response, i am afraid that these are issues which the authors of the NEJM research letter have not investigated in depth so far. Moreover, I hope they investigate how cloud-chasing is performed, what kind of atomizers and liquids are used and how the vapers use these devices. CE4s are not used for cloud chasing (and it is impossible to used a CE4 for cloud chasing).
As I said, the nature of the e-cigarette makes it possible for everyone to find as many aldehydes as he wants, just by abusing the device. The findings will be credible in terms of the amount found (we verified that), but will be irrelevant to realistic use and true exposure. This has nothing to do with the methodology of analysis of aldehydes.
For these reasons, it was extremely inappropriate to extrapolate cancer risks and misinform the public about e-cigarettes being more carcinogenic than tobacco cigarettes. Additionally, it was extremely inappropriate to present in the same figure the formaldehyde exposure from tobacco cigarettes as mean and standard deviation while the exposure from e-cigarettes as mean and standard error of mean. The graph does not show that, in the multiple repetitions of measurements made by the authors, the variability in the findings was so huge that one should doubt about the validity of the methodology they used.
Therefore, due to statistical mis-presentation and mis-information on cancer risk, the research letter published in NEJM should be retracted.