Thursday, January 30, 2014

New Study of Passive Vaping Shows No Evidence of a Significant Public Health Hazard

A new study published online ahead of print in the International Journal of Hygiene and Environmental Health is one of the first to examine levels of chemicals in the ambient air of a real-life setting in the presence of electronic cigarette use.

(See: Schober W, et al. Use of electronic cigarettes [e-cigarettes] impairs indoor air quality and increase FeNO levels of e-cigarette consumers. International Journal of Hygiene and Environmental Health 2013; doie: 10.1016/j.ijheh.2013.11.003.)

The study analyzed the levels of a large number of pollutants in the ambient air of a room in an office building during the presence of three smokers using electronic cigarettes. The room was moderately ventilated at 0.56 air changes per hour.

The most important results were as follows:

1. "Indoor concentrations of CO and CO2 showed no difference between control and vaping periods."

2. "Formaldehyde, benzene and the pyrolysis products acrolein and acetone did not exceed background concentrations."

3. "With regard to the seven PAH classified as probable carcinogens by the IARC, the concentrations increased on average by 20% from 122.8 ng/m3 (control) to 147.3 + 26.2 ng/m3."

4. "No significant increase was observed for the toxic and potentially carcinogenic elements cadmium, arsenic and thallium."

5. "The concentrations of elements and metals showed a 2.4-fold increase for aluminum." [However, there was no significant increase for any other metal, including copper, chromium, nickel, lead, tin, vanadium, or zinc.]

The Rest of the Story

This study, although limited to only three brands of electronic cigarettes, provides reassuring evidence that there do not, at present, appear to be major concerns about substantial health hazards associated with secondhand exposure to electronic cigarettes. 

Prior to this study, the most significant health concern regarding passive vaping was the possibility of exposure to carcinogenic and toxic aldehydes and pyrolysis products including formaldehyde, acrolein, and acetone. However, this study found no increase in concentrations of any of these pollutants under realistic (real-life) conditions.  

Despite a small increase in polycyclic aromatic hydrocarbon concentrations, there were no significant increases for any of the known or probably carcinogenic compounds.

With the exception of aluminum, the concentrations of most metals were substantially lower during vaping than in the no vaping condition. Metals therefore do not appear to be a significant health issue at this point in time.

In summary, this study helps to alleviate concerns raised by prior research and does not raise any new concerns. While more research is clearly needed, especially because there are so many different brands of electronic cigarettes on the market, the current evidence does not point to any substantial health hazards associated with passive vaping.

In light of these findings, the best that the study authors could do to implicate electronic cigarettes as a human health hazard was to proclaim that "e-cigarettes are not emission-free." If that is the worst thing that thsee researchers can say, then it certainly doesn't appear to rise to the level of a known health hazard for which government intervention is necessary at this time.

There are clearly two ways to spin this study. One is to emphasize the study's reassuring findings that there were no substantial causes for serious concern. Another is to spin it as these authors did, stating their conclusion as follows:

"Analysis of indoor air quality during vaping sessions showed that e-cigarettes are not emission-free." This was the second time the authors used this phrasing to summarize their findings. Right now, that e-cigarettes are not emission free appears to be about the most alarming thing that can be said about them.

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