Nope.
Dr Laugesen says, "It is impossible for an e-cigarette to cause lung cancer" - and it is even less likely that any other kind can be caused. There is a very low level of carcinogens in e-liquid (about 8ng/mg) which come across with the nicotine, but these levels are "Millions of times lower than conceivably harmful to health" according to Prof Rodu.
This level is also typically identical to that in NRTs such as nicotine skin patches, so that if ecigs can promote cancer, then so can NRTs. No one has ever suggested that there is the slightest likelihood of that occurring and there is certainly no evidence for it.
In addition, nicotine does not cause cancer or even exacerbate existing cancer in humans. There is a mountain of scientific evidence for this statement: the hundreds of clinical studies over nearly three decades carried out on Snus consumption in Sweden. The giant-scale meta-analyses of dozens of Snus studies carried out by PN Lee, and Lee & Hamling, tell us that Snus does not elevate risk for any disease (and by definition this includes any/all types of cancers).
There is also the matter of the facts as well as the clinical evidence: thirty years of epidemiology tells us that Sweden has the lowest tobacco-related death rate of any developed country in the world by a wide margin, despite having a Snus user prevalence of over 20% among the population; and that Sweden has the lowest male lung cancer and oral cancer rate in the EU. If Snus caused cancer then oral cancer would be a natural place to look for some sort of effect: there is none.
There are one or two clinical studies that show an increase in risk for pancreatic cancer, and also one or two that show the opposite: a protective effect against cancer. These results are contradicted by about 150 others which show no elevation or reduction of risk, and are therefore regarded as 'outliers'. Their methodologies have also been reported as suspect or even secret.
Some brands of Snus can supply more nicotine than some cigarettes, so that the alkaloid is certainly present in sufficient quantities to be effective. Blood plasma tests demonstrate high availability. Therefore if ad lib consumption of Snus over many decades can be shown to be without any statistically-demonstrable risk, it could be assumed with a reasonable degree of validity that nicotine is a low-risk drug without significant issues (except for those with a genetic reason to avoid it). This is the current mainstream medical opinion since even the UK's MHRA, a violently anti-vaping government agency as they work for the pharmaceutical industry, has described nicotine as "A very safe drug". Other experts describe nicotine as "relatively harmless" and so on.
Nicotine consumption probably has as much significance to health as coffee consumption (caffeine).
So as far as vaping is concerned, we know that the carcinogen level is so low as to be insignificant, and that nicotine is a safe consumer drug with no issues (except in certain circumstances for certain individuals - as is true of many materials in any case). Note also that nicotine is a normal ingredient in the diet and everyone tests positive for it, so that consuming nicotine via other channels is boosting the dietary consumption rather than consumption of something entirely alien.
There are only three circumstances in which I have any concerns about the significance of vaping to health:
1. Persons with lungs severely damaged by smoking need to exercise extreme caution. If you have emphysema or Stage 3 or 4 COPD then realistically you would be much better off with Snus. People die from these conditions and you won't live longer by continuing to inhale extraneous materials. There is probably an increase of risk for pneumonia.
2. We don't know much about the implications of inhaling food flavours over periods of decades. Some flavours will be completely innocuous (harmless), but others are known to be lethal (such as diacetyl, the synthetic butter popcorn flavour). Until we have a great deal more research on this particular issue, no one can realistically make any factual statements about the issues. That won't be the case for about 20 years.
3. The vendors of e-liquids have been notable by their unwillingness to take safety issues seriously by organising extensive retail product testing. Or, if they have done so, they haven't published the results - which is equally worrying. This means there is always going to be the potential for contaminants or incorrect flavourings to be present, since no one can prove otherwise. The best way to avoid potential problems is to pay top dollar for your e-liquid, since then there is a chance of good quality and some testing. There is no possible way that cheap e-liquid can be said to be safe, since testing is expensive, therefore a cheap e-liquid has received no testing - QED. It is probably fair to say that at least 90% of e-liquid vendors don't have a clue what is in their finished retail product. You can virtually guarantee that vendors of cheap e-liquid are selling materials with a completely unknown composition and just crossing their fingers for luck.
Prove me wrong !
