I have been vaping for a few years now and I was a 2 pack a day smoker before that. But it's not been till the last year or so that I finally put it together.. it's leaving a residue on everything. I'm sure most of you have gave your windshield a cussing.. my question is.. what is this doing to our lungs?? Can someone point me to a link of some credibiliable medical info? I took it as hey, it's gotta be better than cigs and never thought about it again. But now I'm 2+ years cigs free and vape 0 NIC and pretty sure I can put the mod down no problems, but I enjoy it. However, I would like to know what's going on.