First hand smoke comes from all combustible tobacco products. This includes Cigarettes, Cigars, Pipes, Hookah, and VAPES. This is the primary source of nicotine addiction. No amount of Second hand smoke is safe and Juul study shows secondhand vaping emissions are less toxic than cigarette smoke E Cig Vapor Or Secondhand Smoke: Which Is Worse For You? YouTube Secondhand Smoke vs Vape: What the Science Says Second hand vaping exposure very low compared to second hand smoking UCL News UCL University College London Parents using e cigs expose kids to dangerous secondhand vapor Futurity