My background is as a Respiratory Therapist. I have asked many Physicians and although they are cautious in advocating vaping, they all have said that if it gets someone off of cigarettes then do it. I have scoured any and all documentation and have yet to see anything definitively stating that vaping is as harmful as analogs. There also exists enough anecdotal info from those who have been able to quit, that this is an effective and at this time, a low risk alternative. I have no doubt that over time there will be studies that will show some negative effects of inhaling a foreign substance, but after 45 years of smoking, I glad to be part of the experiment.