Electronic cigarettes, or e-cigarettes have become commonplace as a safer substitute for the real thing. But are they safe to use?
One important consideration is that at the moment e-cigarettes are not regulated in many countries, including the UK. This means, like all unregulated products that have a potential health risk, you don't know that what you are using contains only what is supposed to contain. There is no magic wand for this, apart from buying from legitimate brands, ideally through a known major retailer, who will hopefully have done some checks for you.
The liquid you put in an e-cigarette (assuming it's a legitimate one) has nicotine, extracted from tobacco, flavourings and suspension fluids that work well with the vaporising process, typically propylene glycol and glycerol which in themselves are both pretty much harmless.
When you inhale this stuff, either actively or as a passive recipient of someone else's vapour, you are taking an aerosol - fine droplets of liquid - into your lungs. This can happen perfectly naturally, for instance with some strong-smelling natural substances. But having unwanted material in the lungs always has the potential for risk, specifically for causing cancer.
The biggest concern here is not the original chemical constituents, but rather than the heating process that sends the vapour out can break down some of the suspension fluid into formaldehyde. In small quantities this isn't a problem - our bodies deal with formaldehyde all the time - but in larger quantities formaldehyde is a carcinogen, particularly around the respiratory system.
At this stage there hasn't been enough research to confirm the early findings, but if the data available so far is correct, heavy users of e-cigarettes could have a significant cancer risk - possibly as high a risk as from smoking in the first place. In the balance, cigarettes have a whole range of negative impacts, not just lung cancer, so this isn't an argument for going back to smoking cigarettes. And if an e-cigarette is used as a vehicle to fairly quickly stop smoking altogether, on balance it may be worth using (though patches, gum and other sources of nicotine don't carry this potential risk).
However, what this does suggest is that no one should use e-cigarettes just for the sake of it, and should only consider using them in a tapering off programme to quit smoking if options like patches and gum aren't working. And it also means we ought to see e-cigarettes banned from all the locations we ban conventional cigarettes - as the risk from passive inhalation is certainly present.
For the future there are a number of steps that should be taken. E-cigarettes should be regulated and licensed as vehicles for drug dispensing. There needs to be significantly more research into the production of formaldehyde and any other potentially dangerous substances. And there should be research into safer suspension fluids.
The principle of e-cigarettes is good, but there is evidence that this still very young product needs significantly more work to ensure that it is a safe substitute for tobacco.