third-hand smoke
n.— «Parents who smoke often open a window or turn on a fan to clear the air for their children, but experts now have identified a related threat to children’s health that isn’t as easy to get rid of: third-hand smoke. That’s the term being used to describe the invisible yet toxic brew of gases and particles clinging to smokers’ hair and clothing, not to mention cushions and carpeting, that lingers long after second-hand smoke has cleared from a room.» —“A New Cigarette Hazard: ’Third-Hand Smoke'” by Roni Caryn Rabin New York Times Jan. 3, 2009. (source: Double-Tongued Dictionary)