From an article I read recently...
For an independent view, I call Professor Robert West, director of tobacco research at University College London and one of the UK’s foremost experts in smoking. He surprises me by saying the WHO’s health fears seem to be largely misplaced. Vaping isn’t smoking. It’s the act of burning, he says, that releases the cascade of toxins. “On the science, we’d say there are no grounds for banning it in public because there isn’t a risk to bystanders.” And what about the user? Critics cite the lack of long-term studies on the effects of vaping as cause for anxiety. But even if we could leap forward 20 years, these would be extremely difficult to carry out. “Almost everyone who’s vaping has smoked and many of them still do,” West points out. “How do you tease apart the effect of the vaping from the smoking?”
West believes we have to rely instead on the products’ toxicological profile. “What’s in it? Obviously, the water vapour is fine. Then you’ve got propylene glycol, which is stage smoke. That’s been tested. It does have some irritant properties, but nothing like cigarette smoke, and it doesn’t have the high level of carcinogens. The nicotine is not totally harmless by any means. I’d say, worst-case scenario, they probably carry a 20th of the risk of conventional cigarettes. Best case? Probably a hundredth.” As a smoking cessation device, he says, they’re “quite effective. They’ve probably helped around 20,000 smokers in England stop, over the last year, who otherwise would have carried on. It’s a small proportion, but it’s still 20,000 people.”