The smoke comes from vegetable glycerin. I was using the e-cigs to quit smoking as well. I realized I was just smoking a new (for me) addictive product. People know cigarettes are poison. As is alcohol. But we still love our addictions. My tobacco quitting came when I realized I was spending more on tobacco than food.
All that $hit should be illegal or there shouldn't be another conversation about how bad weed is. Kids will keep using e-cigs as long as they can get their hands on them. The only way to stop them is to make vape liquid illegal. Same goes for THC vape pens. Flower, kief, shatter made correctly, and the like are just different forms of the same thing. When you start adding products to THC vape pens, it makes it an entirely different drug.