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 Digital Download Materials "Secondhand Smoke" Maine Prevention Store Secondhand vape plumes could form lung damaging radicals American Chemical Society Secondhand Smoke and Electronic Cigarette Aerosol Resources US EPA