(See: Schripp T, Markewitz D, Uhde E, Salthammer T. Does e-cigarette consumption cause passive vaping? Indoor Air 2012. DOI: 10.1111/j.1600-0668.2012.00792.x.)
In the experiment, a smoker puffed on an electronic cigarette with one of three types of liquids, or on a regular tobacco cigarette in a sealed chamber while measurements were made of various volatile organic compounds. In subsequent tests, exhaled air from an electronic cigarette user was directly sampled and tested for volatile organic compounds.
The study found that the chief components of the gas phase were propylene glycol, glycerine, nicotine, and flavorings.
The levels of volatile organic compounds during vaping were substantially lower than during smoking. Most of the chemicals detected during smoking were not detected during vaping. The only chemical of significant concern was formaldehyde, but the levels were low -- only 14% of that produced during smoking.
During direct testing of the electronic cigarette vapor (produced by a pump), no formaldehyde was detected.
The Rest of the Story
The results of this study are consistent with those of previous studies which have examined the components of electronic cigarette vapor or investigated the gas phase components produced during the experimental use of electronic cigarettes. Other than the potential effects of respiratory irritation from long-term inhalation of propylene glycol, the main concern appears to be the presence of formaldehyde. However, in this study, formaldehyde levels in the experimental chamber were low and formaldehyde was not detected in the actively sampled electronic cigarette vapor. The most striking finding of the study was the relative safety of electronic cigarette vapor compared to tobacco smoke.
This study confirms that electronic cigarette use is much safer than smoking and suggests that any health risks associated with passive exposure to electronic cigarette vapor are likely to be quite low.
Further studies are necessary to better understand the exact effects that long-term inhalation of propylene glycol may have on the lung and to better characterize the exposure to formaldehyde that may occur from "active" or "passive" vaping. But there is no question that any risks associated with electronic cigarettes are dwarfed by those caused by smoking and secondhand smoke exposure. Thus, electronic cigarettes are a viable alternative to cigarettes that drastically reduce health risks.
In my opinion, electronic cigarette companies which are claiming that use of their products reduces the health risks associated with cigarette smoking are making factual statements for which there is plentiful scientific evidence. As the FDA is currently considering regulations for electronic cigarettes, it is my hope that the agency will not apply section 911 (the modified risk provisions) to these products -- or at least not apply the regulatory framework established in that section. If strictly applied, section 911 would preclude electronic cigarette companies from arguing that these products are safer than regular cigarettes. This would essentially force companies to withhold the truth from consumers and would not serve the public interest.
This study is a death knell for the claims of anti-smoking researchers such as Dr. Ellen Hahn, who have argued that there is no evidence that electronic cigarette use is any safer than smoking.
Remember that as I reported back in August, an article published in the March issue of the journal Nursing Clinics of North America claimed that there is no scientific basis to argue that cigarettes are any more harmful than non-tobacco-containing electronic cigarettes that merely vaporize nicotine from a solution containing nicotine, glycerin, and propylene glycol. These authors assert that despite the fact that electronic cigarettes contain no tobacco and involve no combustion, produce no smoke, and do not contain most of the tens of thousands of chemicals and more than 60 known carcinogens in tobacco smoke, there is no scientific basis to claim that tobacco cigarettes are any more harmful than electronic ones. The article stated that: "no scientific basis currently exists for making claims of ... reduced harm ... for e-cigarettes."
This study adds to a body of scientific evidence that destroys the validity of that argument. It is now clear that electronic cigarettes are reduced harm products (compared to conventional cigarettes). Anyone who continues to claim that there is no scientific basis for such a claim is either lying or living in a secluded cave without internet access.