Does smoke from marijuana vaporizers contain carcinogens?

YES. Numerous studies have shown that marijuana smoke contains carcinogens, and irritates the lungs. Marijuana smoke contains 50-70% more carcinogenic hydrocarbons than tobacco smoke. Marijuana users usually inhale more deeply and hold their breath longer than tobacco smokers do -- increasing lungs' exposure to carcinogenic smoke. Also there's dysregulation in pot smokers' lung epithelial cells.
Yes but not problem. Yes but does not cause increase in cancer, even smoked heavily in joints chronically.