grafulyjaded makes a good point, a new and the only compelling one I've heard here
So few things
1. 100% with out a doubt I'm certain that using a e-cig/vape pen to get your nicotine fix is less toxic/caustic than burning vegetable matter that combusts in to tiny little particles that you lung really can't do anything with but let just sit there and collect with the billion other little combusted particles that sit in the air sacs in your lungs...until they can take no more little particles that don't break down.
2. I'm not a doctor or a shill for the tobacco industry, but my understanding is that nicotine does not cause any type of cancer. Its addictive and a stimulant, but it doesn't cause lung, lip, tongue esophageal and what ever other type of cancer you get from smoking cigarettes...it's pretty much all the other shit(and the repetition)
3. Cigarette smoke to someone who doesn't smoke is really nauseating, the ashtrays are stinky and the smell in your hair (unfortunately not talking about mine as I have so little) and clothes. I remember I had this hoodie I'd wear to bedrock billiards. One night after getting home stuffed it in luggage with other clothes. Two days later I opened it up and the smoke stench was noxious and all of it now smelled like it.
I agree there are no standards or long term studies...that is a big unknown to confidently trust one's health on
those unknowns should make you think hard about something that you do 50-100 times a day!
I think that's the biggest problem with smoking, the repetition. The shear quantity of the one thing you keep doing. If you poked your arm with your index finger in the same place, the same amount of times you took a puff, over the years, I think the likelihood of that one spot getting cancer or something fatal is high.
One outlier is the 3rd party vape...that might actually have some merit if it is proven it is even a little toxic to other people close by. (especially with Jaded's point)
It's one thing to kill yourselves with your vices, I think you are an ass when you take others with it.