When a cigarette burns, nicotine is released in the form of a vapor that collects and condenses on indoor surfaces such as walls, carpeting, drapes and furniture, where it can linger for months, according to the study.
Study shows that when this residual nicotine reacts with ambient nitrous acid it forms carcinogenic tobacco-specific nitrosamines, or TSNA’s.
TSNAs are among the most broadly acting and potent carcinogens present in unburned tobacco and tobacco smoke,
The most likely human exposure to TSNAs is through either inhalation of dust or the contact of skin with carpet or clothes – making third-hand smoke particularly dangerous to infants and toddlers.
Opening a window or turning on a fan ti air out a room while a cigarette burns does not eliminate the hazard of third-hand smoke. Smoking outdoors doesn't help much either.
Smoking outside is better than smoking indoors but nicotine residue will stick to a smoker’s skin and clothing.
Substantial levels of TSNAs were also found in the truck of heavy smoker, the study says, adding that most vehicle engines emit some nitrous acid that can filtrate the passenger compartment of a vehicle.
Researchers says that the first quantity the reactions of third-hand smoke with nitrous acid.