I don't think the europeans of the 1500's had any clue tobacco was in any way dangerous to peoples health, in fact I'm pretty sure they thought it was a medicinal plant.

It was also probably too expensive for most people to buy and consume enough to be noticeably harmful.

Having said that, a European of the 1500's would know what smoke did to kippers.

Ok then. Replace 1500 tobacco with 1800 opium.

Smoking tobacco has clear negative health consequences today, but the association may not have been so strong when the predominant forms of heating households were open wood and coal fires. It's also worth keeping in mind that smoking tobacco wasn't always the predominant form of taking tobacco, chewing tobacco and nasal snuff are as old as tobacco itself to Europeans, and if Google's ngram viewer is anything to go by, cigars only overtook snuff in the late 19th century (bit of a dodgy data point, since snuff has multiple meanings).

Today some 500k-1m Swedes regularly take snus, and the association with oral and pancreatic cancers is tenuous at best, and the BMJ reported in the 1980s that there has been one case of nasal cancer linked to nasal snuff in the 300 years it has been used in the UK. Chewing tobacco is a little more harmful but not by much.

Cigarette companies have done a good job the past century of associating any harmful effect of smoking tobacco with tobacco and nicotine itself, despite cigarettes being 100x more harmful than either snus or snuff.