A new study released by the University of St. Andrews in the United Kingdom has shown that under appropriate operating conditions, an e-cigarette can have more than 99% less carcinogens than traditional smoking.
Appropriate operating conditions would be using the mod at the recommended wattage / voltage for the coil resistance of the atomizer.
The only period in the study which the measured aldehydes in the e-cig vapor were remarkably elevated was when the voltage (and coil temperature) was set far too high and the e-cigarette in question was producing dry hits, something every vaper avoids like the plague.
How the Study was Conducted
Methods used in the study, from the abstract which can be found at BMJ Tobacco Control:
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 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<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 >> heat-not-burn >> e-cigarettes (normal power)≥nicotine inhaler.
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.
As you can see from the results, while e-cigarettes are capable of spanning a wide area of risk, a large majority of the time the harmful emissions are less than 1% that of smoke and higher carcinogen exposure can be avoided by setting your vape mod at a reasonable power output level.
The emissions from regular vape usage are comparable, greater than or equal to a medicinal nicotine inhaler.
Dr. Michael Siegel of Boston University School of Public Health made a very strong conclusion in his analysis of the study.
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.
Dr. Siegel went on to say "It makes no sense to lump e-cigarettes in the same basket as tobacco cigarettes, given their drastically different health risks." He also praised Dr. Scott Gottleib, FDA Commissioner, "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."
Other Findings - Heat-Not-Burn devices are better than smoking
(But not as good as vaping)
The study also looked at the newly revived heat-not-burn devices that are currently in the application process for sale in the United States. These heat-not-burn devices, such as the IQOS (I-Quit-Ordinary-Smoking), act by heating up the tobacco to release nicotine vapor while not actually causing any smoke to be released.
The heat-not-burn devices provide around 70% of the nicotine of a normal cigarette along with the same draw and similar flavor. The results from the study show that while heat-not-burn technology produces far less of the aldehyde compounds than smoking, 90% less, e-cigarettes still make for a less harmful nicotine delivery method.