I have been distracted from my general vape waffle this morning by a link to a blog post by Stanton Glantz of UCSF (more about him on another day maybe). In his blog he is trumpeting a ‘study’ by ASHRAE, which apparently stands for the American Society for Heating Refrigeration and Air Conditioning Engineering. What does this have to do with vaping? Well apparently ASHRAE think themselves qualified to opine on the hazards of e-cigarettes in terms of indoor air quality.
It appears they base their study on a photograph which shows a consumer….wait for it…exhaling vapour, more properly called aerosol. It’s ground breaking stuff, I’m sure you’ll agree. They then go on to use the analysis from the 2013 Goniewicz study to determine what might be in the exhaled aerosol and exposures to a non user trapped in a room with a consumer. The difficulty with this is that the Goniewicz study used smoking machines to analyse the contents of emissions from 12 e-cigarettes. It does not take into account the respiratory absorption which would occur if there were a human on the end of it, rather than a machine. Additionally, the Goniewicz study does not take into account the ‘dry puff’ phenomena (a machine, unlike a human, cannot detect dry puffs and so will continue to vape when a human would stop and solve the problem).
Unperturbed by these issues with their base analysis ASHRAE then continued their study on the basis that the consumer in their theoretical situation would exhale 100% of what they inhaled, and that the hapless non vaper would inhale 100% of the compounds in the vapour in the indoor air that they breath.
Having deduced their totally unrealistic exposure levels they then compared them to the ‘No Specific Risk Levels’ (NRSL) for cancer, and to ‘Chronic Reference Exposure Level’ (CREL) guidelines for non cancer health effects. Unfortunately for them there are no CREL guidelines for nicotine or propylene glycol (maybe because no one has identified a hazard risk worthy of producing a guideline?) so they used 1% of OSHA eight hour permissible exposure guideline instead. There is no explanation as to why they chose that figure.
For indirect exposure (passive vaping) all elements other than propylene glycol and nicotine came in well under the levels identified as a risk. Nicotine and propylene glycol did fail their (apparently made up) standard and they go on to summarise that this represents a significant health risk. The study contains no information as to why the inhalation of nicotine at these levels may be a health risk, and refers only to a completely different study (with different exposure levels – Wieslander et al ) to support the contention that propylene glycol is harmful to health. This does not prevent our intrepid researchers concluding that “e-cigarettes emit harmful chemicals into the air and need to regulated in the same manner as tobacco smoking”. Nor does it deter Stanton Glantz from concluding that “It’s bad”. Way to go ‘Prof’…