You might not be a smoker yourself, but hanging around people who are smoking can cause you to inhale noxious cigarette fumes. For years, scientists have cautioned against the ill-effects of such second-hand smoke. Now they’re warning about the dangers of “third-hand smoke”—the chemical traces that cling to a smoker, and that are left behind in a room where someone has been smoking.
A team of researchers at the Lawrence Berkeley National Laboratory found that remnants of a smoke don’t just inertly settle onto surfaces, they can react with a common gas (nitrous acid, which is emitted from gas appliances and vehicles, among other sources) to create carcinogenic compounds known as tobacco-specific nitrosamines (TSNAs) [Scientific American]. The study (pdf) was published in Proceedings of the National Academy of Sciences.
