Dr. Eissenberg: Electronic cigarettes, or e-cigs are generally constructed of three different parts.
There's some sort of electric power source, usually battery, there is heating element and then there is some sort of container or reservoir for nicotine liquid.
And the idea is that once the battery is activated it powers up the heater the heater heats the liquid and produces a vapor that the person inhales with the intention of inhaling the nicotine vapor.
That nicotine liquid is almost always in one of two vehicles, it's nicotine mixed with propylene glycol or nicotine mixed with vegetable glycerin and then that mixture is almost always will include some type flavoring and perhaps sweeteners.
In e-cigarettes versus the nicotine in tobacco it is actually a very relevant question because whereas it may be very expensive to synthetically produce nicotine it is relatively inexpensive to extract it from a tobacco plant and so in fact the nicotine in tobacco cigarettes is the nicotine in the tobacco plant, the nicotine in electronic cigarettes is nicotine that's been extracted from the tobacco plant so either way it is the same drug, and in fact it has the same biological basis.
Nicotine is psychomotor stimulant which means it excites your muscles at the level of the neuromuscular junction.
It also acts on neurons in the brain. It's interesting because at low doses it has a mild excitatory effect kind of like caffeine does.
At high doses it can cause seizures and death. So it is well known that unlike caffeine, it is very easy to overdose on nicotine. In terms of future research on electronic cigarettes, I think I am pretty concerned with what they do.
What they do when people use them the way they are intended what they do when people use them the way they are not intended. And by what they do I mean, do they deliver nicotine, do they deliver other toxic things that could be harmful?
What I do worry about is what the long term effects of many, many puffs per day, week after week, month after month, year after year, of propylene glycol vapor or vegetable glycerin vapor or vapor made up of all those flavorings what those effects would be on the human lung. And I don't think we know the answer, and until we know the answer it is really hard to say that long term use of these products is sure to be safe.