Actually, I was saying (and sorry if I was unclear) that everyone here does agree with you that breathing negligible amounts of smoke doesn’t pose any non-negligible health risks.
What we’re saying is that you can’t extrapolate from that to sweeping, unqualified statements like “smoking outdoors never does any harm to anybody, period”.
How much harm secondhand smoke does depends on how much of it non-smokers are breathing. While in most outdoor spaces non-smokers may be breathing only negligible amounts of smoke, in some outdoor spaces they’ll be breathing more. I mean, this is just simple common sense, right?
Yes. For example, this study by researchers at UC Berkeley and Stanford, “Real-Time Monitoring of Outdoor Environmental Tobacco Smoke Concentrations” (PDF), found that in some circumstances, concentrations of environmental tobacco smoke (ETS) in outdoor environments are comparable to those in smokers’ indoor environments:
Since, as you’ve already acknowledged, secondhand smoke (ETS) in indoor environments can be harmful, then comparable amounts of secondhand smoke in outdoor environments can be harmful too, right?
In other words, as I said, how much harm secondhand smoke does depends on how much of it non-smokers are breathing. And the amount of secondhand smoke in outdoor environments can vary from negligible amounts up to levels comparable with the levels in smoky indoor environments.
Which is why it’s silly to try to make sweeping statements about outdoor smoking never doing any harm at all. If there’s enough smoke concentrated in a particular site, breathing it will involve non-negligible health hazards irrespective of whether the site is indoors or outdoors.
Seriously, did you really need cites from published research for what IMO are such basic common-sense conclusions?
I agree that the health risks to your neighbor from your smoking in your own (well-ventilated) backyard are probably completely negligible in most cases. And I agree that it’s wrong for overzealous legislators to pretend that mostly-negligible health risks are the same as serious health risks.
But I don’t think that the right way to approach the problem is to insist on unsupportable absolutist over-generalizations about outdoor smoking never causing any harm to anybody, period. Obviously, outdoor ETS can cause harm, as long as there’s enough of it, just as indoor ETS can. Trying to deny that obvious fact will just make smoking opponents even less sympathetic to your side of the argument.