[alexasmyths]

If there is a stove-pipe then they are not breathing any fumes.

[snrplfth]

A lot of stovepipes leak fumes, an in any case most people in the Roman empire had no such thing as a stovepipe. It's absolutely a myth that most premodern people had "clean air". No, it was generally filled with smoke, dung dust, mold spores, etc.