James F. Pankow , Kilsun Kim, Kevin J. McWhirter, Wentai Luo, Jorge O. Escobedo, Robert M. Strongin, Anna K. Duell, David H. Peyton
PLoS ONE 12(3): e0173055. doi:10.1371/journal.pone.0173055
This study was reviewed by Dr. Konstantinos Farsalinos, Onassis Cardiac Surgery Greece, Department of Pharmacology, University of Patras, Greece: Study titled “Benzene formation in e-cigarettes” found that air has more benzene than e-cigs
Of course, the press statement promotes this headline: Cancer-causing benzene found in e-cigarette vapors operated at high power, which Dr. Farsalinos points out as:
It is very interesting to once again see the inconsistency between the study findings and the press statement.
Continuing his review of the actual study and data, he reveals:
The results of the study are very interesting. At the recommended setting of 6 W with the EVOD (I repeat, at 5 second puffs), they found from non-detected levels (in most of the samples) to 0.16 μg/g liquid consumption (keep these numbers). At 13 W (dry puffs), they found up to 24 μg/g. With the Subtank, they found either non-detected or up to 0.19 μg/g even at the extreme power settings.
What do the findings mean? It depends on how you want to look at it. The authors calculated the concentration of benzene in inhaled air, and report levels up to 5000 μg/m3 air (at dry puffs of course). Compared to the ambient levels of 1 μg/m3 of benzene, everyone would think that this is a disaster.
But not really, this methodology suffers from a major problem. Humans take about 12 breaths per minute, i.e. 17,000 (thousand) breaths per 24 h. The volume of air inhaled in 24 h is 20 m3. So, the daily exposure to benzene from ambient air is 20 μg. Even if you assume that Subtank at 25 W with 5-second puffs represent realistic conditions (they are not), you need to consume 105 mL e-liquid per day in order to be exposed to the same levels of benzene as breathing ambient air. For the EVOD under normal vaping conditions, you need to vape 125 mL e-liquid per day.
The press statement mentions that: “The power levels used in the study were still far below those accessible to users on some devices, which can exceed 200 watts”. This statement is similar to saying that: “We crashed with a car in Trafalgar Square with a speed of 100 mph, but still that was far below the 150 mph speed that cars can reach”. Another similar statement would be: “Eating 5 kg of vegetables in one meal can lead to death, but that is still below the tens of kg available in grocery store where customers buy their vegetables”.
I understand it is frustrating to desperately try to find a problem but fail. And this is not the first time, we’ve seen it in the past (and recently) with formaldehyde and other toxic aldehydes (just wait for a couple of papers that will be published soon). However, this still does not prevent the mispresentation of evidence and science. Also, scientists completely ignore the dry puff phenomenon and instead of them verifying realistic conditions in their experiments, they consider theoretical the criticism they get for their own omission! What a disappointment for the scientific community…
In conclusion: “Benzene formation in e-cigarettes: it does not exist…”
So it appears that we have another “Formaldehyde” scare… THANK YOU DR. FARSALINOS! We’ve always been able to count on his honest research and analysis to tell us the the full story, be it good, bad OR ugly.journal.pone.0173055