According to this article a study has found there could be potentially damaging effects from “third hand” cigarette smoke. Scientists have found that significant quantities of cancer causing chemicals are produced on surfaces even when a smoker has been away from the room for several days. It is these chemicals that linger in the room after smoking that they refer to as third hand. The chemicals are found to be present in significant amounts on chairs, tables, carpets and even skin. Nicotine can stick to indoor surfaces for several days where it interacts with nitrous acid released by car exhausts and gas appliances. When combined these chemicals form something called tobacco-specific nitrosamines which can cause cancer. It is thought that the amounts found are enough to pose a danger to non-smokers and young children so it seems there may be yet another way that smoking can kill you, albeit indirectly.