There are good reasons why electronic cigarettes are proving controversial.
Other nicotine therapies somehow have a medicinal feel. A nicotine patch mimics a first-aid plaster, while chewing gum carries all kinds of connotations of fresh breath and mouth cleanliness. People who attempt to kick the smoking habit using them are sending out a clear signal - I'm finished with sitting in a fug of exhaled smoke, I no longer want to pose holding a cigarette to my pouted lips.
But e-cigarettes are different. I've been fooled enough by a "real" looking one to mistakenly inform a man "vaping" that he was on a non-smoking train platform. And even the versions which look more like fountain pens emit "smoke" (actually water vapour and the chemical which makes stage smoke, laced with nicotine).
It's that which has public health experts worried. Will the sight of people vaping make real smoking more acceptable and more appealing?
I admit I'm worried. I thought I'd successfully persuaded my 9-year-old that smoking was "old fashioned" (which I'm presuming will be the last thing she'll want to be when she's older).
But recently, quite unprompted, she said to me, "Don't worry Mummy, if I do take up smoking, I'll smoke those electric cigarettes instead".
The authors of today's report point out the proportion of e-cigarette users who took up the habit having never smoked is very small - 0.2%. They also say that, so far, there is no evidence that e-cigarettes are "re-normalising" smoking.
For the sake of the generation who've absorbed the public health messages about tobacco, let's hope things stay that way.