Vaping Indoors and How it Contributes to Sick Home Syndrome Bactronix Have you heard of Third Hand Smoke , When most people think about the risks of smoking, they picture first or second hand smokethe smoke you inhale or breathe when someone lights up near you. But Second hand vaping exposure very low compared to second hand smoking UCL News UCL University College London Second hand e cigarette vapour increases risk of poor respiratory health, study finds Nursing in Practice