Thirdhand smoke (THS) is a term used to describe the residual contamination from tobacco smoke that lingers in rooms long after smoking stops and remains on our clothes after we leave a smoky place. It may seem merely like an offensive smell, but it is also indicative of the presence of tobacco toxins. 

Thirdhand smoke consists of the tobacco residue from cigarettes, cigars, and other tobacco products that is left behind after smoking and builds up on surfaces and furnishings. Tobacco smoke is composed of numerous types of gasses and particulate matter, including carcinogens and heavy metals, like arsenic, lead, and cyanide. Sticky, highly toxic particulates, like nicotine, can cling to walls and ceilings. Gases can be absorbed into dust in a room, carpets, draperies, and other fabrics or upholsteries. 
(no-smoke.org/smokefree-threats/thirdhand-smoke/)