The one association with so-called “second hand smoke” that holds up is asthma in children whose parents smoke.
Of course, correlation is not causation, smoking is overwhelmingly a lower class behavior and lower class living standards also predispose to asthma and other childhood illnesses.
The interesting thing about asthma is that the proportion of cases seems to have exploded in the 90s, which is the decade where smoking bans were implemented.
Not so many cases of asthma from kids up to the 70s when so many people smoked.
It seems that the fewer smokers there are, the more asthma cases there are, which makes me think it has nothing to do w/smoke.
they did 3 studies
the first two included family history and were inconclusive
the 3rd did not include family history and they got the results they wanted
that is how govt does science