E Cig Vapor Or Secondhand Smoke: Which Is Worse For You? 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 The Issues of Testing for Secondhand Smoke. Indoor Science How secondhand smoke, thirdhand smoke & vaping affects kids Vaping harms your health Cancer Institute NSW