A common indoor air chemical reacts with residues of tobacco smoke clinging to clothing, skin and surfaces to form potent carcinogens, researchers at Lawrence Berkeley Laboratory reported in a study published Monday. A few years ago, researchers began paying closer attention to the potential health effects of "thirdhand smoke," which is a thin layer of toxic substances from tobacco smoke that settles on surfaces long after cigarettes have been extinguished. [2]

The study released Monday by the Lawrence Berkeley National Laboratory found that third-hand smoke is especially dangerous when nicotine comes into contact with a common indoor pollutant typically found in household gas appliances. The combination clings to walls, floors, carpets, drapes and other furniture and can last for days, weeks or months, the study concluded. [3]