Dear Dr. Farsalinos.
Thank you for your comments on our report “Health risks associated with e-cigarettes - English summary (pdf).”
In your blog post, you suggest that the following paragraph in our report is not true:
Nicotine levels in the environment following passive exposure to e-cigarette aerosols causes similarly high nicotine levels in the blood as that of passive smoking of regular cigarettes. This means that one can expect similar harmful nicotine-related effects of passive smoking from e-cigarettes as for regular cigarettes. This does not mean that passive exposure to aerosols from e-cigarettes causes carcinogenic effects, but that passive smoking may affect the cardiovascular system, have stimulatory effects and contribute to addiction.
In the first study, 15 never-smokers underwent a control session, a passive tobacco cigarette smoking session and a passive e-cigarette smoking session. Serum cotinine levels were 2.4 ± 0.9 ng/ml in passive tobacco smokers and 2.6 ± 0.6 ng/ml in passive e-cigarette smokers. These are similar levels.
In the second study, researchers measured nicotine levels in households. Generic mean levels of airborne nicotine were 0.74 μg/m3 in the tobacco-smokers’ homes and 0.13 μg/m3 in the e-cigarette users’ homes. These levels, while not identical, are statistically similar because non-smokers’ homes held nicotine levels of 0.02 μg/m3.
More research is needed before we can draw a final conclusion about the health risk of secondhand e-cigarette use, and we state this clearly throughout the report. As you’ve mentioned, other studies have used different methods to measure airborne nicotine levels, and found differing concentration levels in tobacco-smoke and e-cigarette vapor.
All of these findings must be replicated in future studies, and epidemiologic studies will be coming in some years. Hopefully there will be more informative studies that will improve the basis for the assessment of risks of e-cigarette use.
However, we stand by our conclusion that a health risk cannot be ruled out.
You also claim that we are “legally and scientifically” obliged to retract the aforementioned paragraph from our report. We disagree. Every day, researchers publish studies and reports which contradict existing studies. This is done precisely so that other scientists may put those findings to the test and uncover more evidence. If researchers had to retract articles simply because their conclusions do not match other findings, modern science would cease overnight.
You also claim that the conclusions of this report are highly disputed. Our conclusions are by and large similar to those of the Office de Preventions du Tabagisme in France, Public Health England, the Centers for Disease Control (CDC) in the United States, and the World Health Organization (WHO). The latter two include even more critical remarks on e-cigarettes than this report does.
Our main aim is to prevent health effects of nicotine in vulnerable populations (e.g. pregnant women, children) and prevent new recruitment to nicotine dependence (and possible dual use of e-cigarettes and tobacco), while at the same reduce health effects of tobacco in tobacco users.
There are many uncertainties about the possible effects of e-cigarettes because of the relative scarcity of studies and especially chronic studies. We state this clearly throughout our report.