Third-Hand Smoke

Quoting The New York Times:

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 smoke has cleared from a room.  The residue includes heavy metals, carcinogens and even radioactive materials [...] Third-hand smoke is what one smells when a smoker gets in an elevator after going outside for a cigarette, [Dr. Winickoff] said, or in a hotel room where people were smoking.  "Your nose isn’t lying," he said.  "The stuff is so toxic that your brain is telling you: ’Get away.’"