Why so obviously wrong? Seems reasonable to me that chimney smoke – defined as air with heavy particulates created from burning wood – might fall back down to the ground (and thus into surrounding buildings) once it has cooled.

I'm not saying it's right, but it doesn't seem obviously wrong to me. Regardless, I'm sure whatever "research" there is must be based on something! A citation would have been appreciated so we could judge for ourselves...

If 70% of chimney smoke re-entered nearby buildings, then those times when most buildings were burning, the air inside them would be nearly as smoky as what come out of the chimney. It's also very hard to believe outside of a tenement arrangement. In a village where there's lots of space between houses, and assuming all particulate matter fell back within the bounds of the village (itself a big stretch), it's hard to see how two-thirds of smoke would find its way back into buildings.

It doesn't mention over what sort of volume/area it re-enters... 70% of smoke from one chimney distributed over the whole neighborhood/town would be more subtle.

edit: "near-by" is a relative term

No, since one persons smoke could enter a dozen peoples houses.

"those times when most buildings were burning" would not have one burner per twelve recipients.

Fall back down to the ground and blow back into sealed houses, though? I think obviously wrong applies to the scenario he wants you to have in mind. Maybe the research has some specific conditions.

Yeah, that is the bit that stuck out as wrong to me as well. For most wind directions, there aren't any nearby buildings downwind of my chimney. Wood burning isn't so common in the city, where I suppose it could be true that most of the smoke finds its way into someone's house.

For an article that uses the word "scientific" so often it's remarkably imprecise. We're told that "there is no amount of wood smoke that is good to breathe", but there's no effort at all to quantify how bad it is. Children who live with wood stoves have higher incidence of asthma... okay, I can believe that. It doesn't mean anything until you give at least a little indication of approximately how much higher.

But I'm probably just another religious zealot.