Carcinogens Form from Third-Hand Smoke
http://www.sciencedaily.com/releases/2010/02/100208154651.htm
http://www.sciencedaily.com/releases/2010/02/100208154651.htm
"Given the rapid sorption and persistence of high levels of nicotine on indoor surfaces, including clothing and human skin, our findings indicate that third-hand smoke represents an unappreciated health hazard through dermal exposure, dust inhalation and ingestion."