A new study published in the journal Tobacco Control reports that the modeled cancer risk associated with vaping is less than 1% of that associated with smoking and is only slightly higher than, if not comparable to the cancer risk associated with nicotine replacement therapy (NRT). In select circumstances, electronic cigarettes produced high levels of aldehydes but only when the voltage was cranked up to excessive levels. Thus, under conditions of normal use, this study finds that tobacco-free e-cigarettes present a drastically reduced carcinogenic risk compared to tobacco cigarettes.
The study methods were as follows: "The cancer potencies of various nicotine-delivering aerosols are
modelled using published chemical analyses of emissions and their
associated inhalation unit risks. Potencies are compared using a
conversion procedure for expressing smoke and e-cigarette vapours in
common units. Lifetime cancer risks are calculated from potencies using
daily consumption estimates."
The results were as follows: "The aerosols form a spectrum of cancer potencies spanning five orders of
magnitude from uncontaminated air to tobacco smoke. E-cigarette
emissions span most of this range with the preponderance of products
having potencies less than 1% of tobacco smoke and falling within two orders of magnitude of a
medicinal nicotine inhaler; however, a small minority have much higher
potencies. These high-risk results tend to be associated with high
levels of carbonyls generated when excessive power is delivered to the
atomiser coil. Samples of a prototype heat-not-burn device have lower
cancer potencies than tobacco smoke by at least one order of magnitude,
but higher potencies than most e-cigarettes. Mean lifetime risks decline
in the sequence: combustible cigarettes much greater than heat-not-burn, which is much greater than e-cigarettes (normal power), which are greater than or equal to nicotine inhaler."
The study concludes that: "Optimal combinations of device settings, liquid formulation and vaping
behaviour normally result in e-cigarette emissions with much less
carcinogenic potency than tobacco smoke, notwithstanding there are
circumstances in which the cancer risks of e-cigarette emissions can
escalate, sometimes substantially. These circumstances are usually
avoidable when the causes are known."
The Rest of the Story
This study should put to rest any doubt within the tobacco control movement about whether vaping greatly reduces health risk compared to smoking. Numerous anti-tobacco groups and health departments have repeatedly asserted that vaping is no less hazardous than smoking, but this claim is false, and the present study adds significantly to the already substantial evidence that vaping is orders of magnitude safer than smoking. The anti-tobacco groups and health agencies that have made such statements should immediately correct them and issue retractions to alert the public to these important findings.
These results add strong empirical support to the new FDA approach to tobacco products, announced one week ago by FDA commissioner Dr. Scott Gottlieb, which emphasizes the regulation of tobacco products and e-cigarettes based on the wide differential in their health risk. It makes no sense to lump e-cigarettes in the same basket as tobacco cigarettes, given their drastically different health risks. However, that is precisely what the FDA was doing prior to Dr. Gottlieb's appointment as the new commissioner. Now, the agency is taking a much more sensible and evidence-based approach.
While this study does find that there are conditions under which e-cigarettes can be made to produce rather high levels of certain hazardous chemicals -- most notably aldehydes -- these conditions involve jacking up the voltage to excessive levels that typically produce dry puff conditions, something that vapers would almost certainly detect immediately and not tolerate. Nevertheless, the results do suggest that FDA safety standards related to the maximum allowable voltage or coil temperature may be warranted.