- Wednesday, 04 September 2013 09:26
60 Millions de consommateurs “study”:mistakes in methodology, major problems in presentation
By Dr Farsalinos
The serial with the 60 Millions de consommateurs presentation of a chemical “study” continues, with a barrage of comments criticizing the original article and the magazine trying to answer about the motives of their presentation. I am not in the position to criticize or question the motives of the magazine. However, I am competent enough to discuss about the methodology and its potential implications on the results. Additionally, I can read medical studies and understand their results and conclusions. Finally, I don’t need anything more than basic mathematics in order to compare their results with tobacco cigarettes.
Part of the protocol of the study has been revealed here. They used the electronic cigarette devices (which devices?) to produce 3 second puffs with 30 second interpuff interval. The rate of volume flow is 50ml/3 second (1000ml/minute). Such a procedure is correct, IF we suppose that the device and atomizer are efficient-enough and do not reproduce the dry-puff phenomenon. This is a crucial point. In our study published in International Journal of Environmental Research and Public Health (see full text, it is available with free access) we have explained what the dry-puff phenomenon is; in fact we observed this with the atomizer we originally used for the study. The dry-puff phenomenon is the result of overheating. It is expected that overheating may lead to production of toxic chemicals. HOWEVER, the user immediately detects and avoids this by decreasing puff duration and increasing interpuff interval (or refilling with liquid in case all of it has been consumed). Did the French study examine whether the experimental conditions can result in the dry-puff phenomenon? If not (which is obviously the case), how can they support that the levels of chemicals found are indeed what the average user would get from using the electronic cigarette? In other words, if the testing conditions do not represent real use then the results do not represent real use and are only of theoretical value.
However, that was not the only mistake. A major methodological issue was that between puffs they did not inactivate the vacuum pump but they continued to aspirate air from the environment. Why did they do that? Probably because it was more convenient. However, the result of this procedure is that the final result is not the amount of chemical present in the vapor from 15 puffs. It is the amount present in vapor plus a huge amount of air from the environment. For 15 puffs they needed 7 minutes, since they took 1 puff every 30 seconds starting from 0 time. The aspiration rate was 1000ml/minute and the puffs lasted 3 seconds. Thus they were aspirating 100ml of vapor (2 puffs) and 900ml of air per minute (besides the first minute when they took 1 puff at 0 time, one at 30seconds and 1 at 60 seconds--thus 150ml puff and 850ml air). Thus, the results they report are the amount of chemicals present in 750ml of vapor (50ml per puff multiplied by 15 puffs) plus 6250 ml of air from the laboratory environment. A note of caution: aspiration of air did not result in dilution of vapor, because during the experiment they did not collect the whole amount of air and measure the chemicals afterwards. They were separating the chemicals at the time of aspiration. Therefore, they were adding the chemicals present in the environment. The article should specifically mention that their results represent the amounts present in 15 puffs plus 6250ml of air from the laboratory.
The most important issue however is the problem with the way the “study” was presented. The initial article mentioned that in some cases chemicals were present in higher levels compared to tobacco. But they did not reveal the results in numbers. On their next article, they reported the lowest and highest levels they found. Using simple mathematics and comparing them with the results of Goniewicz and coworkers it is obvious that the levels are by far lower compared to tobacco cigarette (even if we ignore the methodological mistakes). I need to make it clear: the levels THEY reported were by far lower compared to tobacco cigarettes.
The magazine came up on September 3 with a new article providing answers to the letter by the French e-cigarette consumer association AIDUCE. In this article, they fail to acknowledge that the original report of toxic chemicals at levels higher than tobacco was false. They fail (once again) to provide any details on the methodology, besides claiming that it is excellent. Instead, they discuss about the inaccurate labeling of nicotine (which is indeed an issue but cannot cause any harm to the users and was not the reason for the vast misinformation and intimidation related to their original article). However, the most worrying thing is that they make an alarming and appalling statement that electronic cigarettes should not be compared to tobacco because they are just a regular consumer product. This is absolutely outrageous. We are “screaming” every day that e-cigarettes should be marketed for smokers only and should not be used by non-smokers as a new trend or habit. How can a consumer association suggest that they tested e-cigarettes without comparing them to tobacco because it is a regular consumer product? Are they suggesting that the public should consider them a consumer product like everything else and can be used by everyone? This is a very dangerous statement. We have to make clear that e-cigarettes should not be used for any reason besides substituting smoking (partly or completely) or preventing relapse to smoking.
Another issue is about the reporting that chromium was found in e-cigarette vapor. As I mentioned in my previous comment, only hexavalent chromium is toxic. No study has ever clarified whether the chromium found was hexavalent or not. Not only are the other forms of chromium non toxic, but in fact they are an essential mineral for the human organism. It is present in widely-used and approved multivitamin supplements and may have beneficial effects on several parts of the human body. Of course, people are terrorized when they hear about chromium, but the truth is that only hexavalent chromium is toxic, and this should be made clear.
In conclusion, instead of uploading new articles every day without saying anything about the true results and their true implications, I would suggest them to do what every proper researcher would do: reveal the methodology in full detail (it cannot be a secret, such a study has been done before), answer to the real questions about their mistakes and omissions and explain why they falsely reported that the levels found were higher than tobacco.
Dr Farsalinos is a researcher at Onassis Cardiac Surgery Center in Athens-Greece and at Medical Imaging Research Center, University Hospital Gathuisberg in Leuven-Belgium. He is actively involved in research on e-cigarettes’ safety and risk profile.