snuff is finely ground tobacco that can be dry, moist, or packaged in pouches or packets

A 2010 CDC study found higher levels of tobacco smoke by-products in people who lived with smokers, especially children, and that, Secondhand exposure to tobacco smoke causes heart disease and lung cancer in nonsmoking adults and sudden infant death syndrome, acute respiratory infections, middle ear disease, exacerbated asthma, respiratory symptoms, and decreased lung function in children. A study in the Journal of Epidemiology and Public Health found that, When compared with never exposed children, children exposed to continuous secondhand smoke scored higher on self-reported aggressive behaviour and teacher-rated antisocial behaviour in fourth gradesimilarly, children exposed to transient levels of secondhand smoke scored higher on aggressive and antisocial behaviour. As you can see from these studies, tobacco smoke is made up of gaseous toxic compounds like acetaldehyde, hydrogen cyanide, and many others
they change out quickly
Or put another way: Think of all the stuff you dont have to force yourself not to do: Im guessing here but I doubt you have to force yourself not to walk down the street dressed as Tinkerbell the fairy or run naked through the shopping mall or steal cars for a living
Sometimes we just rolled it up in newspaper like a cigarette