In the seventies, the view was often expressed to me by lay audiences that there was no point in stopping smoking, since everything was a carcinogen and so ubiquitous as to be unavoidable. This view was certainly pushed by the tobacco companies with the bizarre support of many environmentalists,

Also see carcinization: https://en.wikipedia.org/wiki/Carcinisation

It also never lists the specific substances nor what one can do about it (not enter the building, don’t lick the ceiling, wear a mask, whatever). Good intentioned but utterly useless.