Wednesday, 13 August 2014 18:07
A study by ASHRAE verifies the safety profile of e-cigarettes, but authors fail to admit it
By Dr Farsalinos
There are a lot of discussions in the social media about a publication by theAmerican Society for Heating, Refrigeration, and Air Conditioning Engineering (ASHRAE) concerning e-cigarette safety. The study was published in ASHRAE Journal, and obviously it was not peer-reviewed. Several methodological mistakes have been found in this paper, which need to be clarified. In reality, the paper verifies that e-cigarettes are by far less harmful that tobacco cigarettes, but the authors fail to admit it and make erroneous conclusions and suggestions.
The authors made some crucial mistakes in their methodology. As a result, they do not present the “worst-case scenario”, but an unrealistic scenario. Firstly, they assume that 100% of the vapor that is inhaled gets absorbed by the user. Obviously, this is far from true, since a substantial proportion of vapor is exhaled by the user. Surprisingly, to assess the impact of environmental exposure, they assume the exact opposite: that 100% of the vapor is exhaled by the user!! They go even further by assuming that this vapor (which is released to the environment is 100% absorbed by the bystanders. It is more than obvious that these assumptions are completely wrong and would not stand any serious peer-reviewing.
Moreover, the authors use the data from Goniewicz et al, but considered only the maximum values found in those experiments. This is a major methodological mistake. Moreover, I wonder why they did not assess environmental exposure by using another paper which measured exactly that. The most probable reason for not using that study is because the authors mentioned: “The study showed that e-cigarettes are a source of secondhand exposure to nicotine but not to combustion toxicants.”
Even if we ignore all these methodological issues, still the findings support that e-cigarettes are by far less harmful than tobacco cigarettes. They mention the cancer risk from exposure to nitrosamines, ignoring that the levels found in tobacco cigarettes are up to 1800 times higher. For heavy metals, I present data from the US Pharmacopeia about the daily maximum permissible daily exposure of heavy metals from medications (based on a 50kg person).
For lead, the permissible levels are similar to what you would get from 1315 e-cigarette puffs, for cadmium 1022 puffs and for nickel 775 puffs (even if we assume 100% absorption, which of course is wrong). The levels found in e-cigarettes may pose some residual risk, but it is by far lower compared to tobacco cigarettes.
This is another study which verifies that e-cigarettes are by far less toxic compared to tobacco cigarette. The authors’ conclusions about the risk from e-cigarette use, and their suggestion to impose similar regulations to tobacco cigarettes, are completely arbitrary, inappropriate and unsupported by their own data (which were calculated by making unrealistic assumptions).