Friday, 17 April 2015 21:09

By Dr Farsalinos

Today, I started reading a study which I received while still in press. The study, authored by an Indoor Environmental Engineering scientist from California and published by the journal “Building and Environment”, evaluated direct and passive emissions from e-cigarettes, and made a risk assessment on the relative risks.

The abstract states that direct exposure is exceeding the safety limit for 7 of the 9 chemicals tested, while passive exposure is exceeding the safety limit for 2 (PG and nicotine) of the 9 chemicals tested. The author concludes that e-cigarettes emit many harmful chemicals into the air and need to be regulated in the same manner as tobacco smoking.

I was eager to read the whole manuscript and find out which are the 7 chemicals exceeding safety limits of exposure, but I was “obliged” to stop reading it when I reached to the methodologies section. The study was a review of the literature, which is not anything wrong. However, for the risk assessment the author mentions (quoting to avoid any misunderstandings or mispresentation): “Direct exposure assessment… The respiratory absorption of the inhaled vapor was assumed to be 100% for all compounds”. So, basically the author assumes that 100% of what a vaper inhales is absorbed from the lungs. Obviously, this is fault. However, in the next paragraph the following “amazing” assumption is made: “Indirect (Passive) Exposure Assessment... For this assessment we assumed that 100% of the inhaled vapor by the user was exhaled into the indoor air and the respiratory absorption by occupants of the exhaled aerosol in the indoor air was 100% for all compounds”.

Many people will consider it a joke. However, it remains a puzzle how you can expect to reach any valuable conclusions by making such assumptions (which are both far from reality). There was no point in reading anything else from this manuscript; however, there is a point in preparing this comment, for everyone to understand how regulators and decision-makers are informed through science and how they make their decisions for public health.