In youth - I jumped on theories and believed them to be Gospel. Wisdom, though, comes a healthy amount of skepticism. For example - eating mashed potatoes causes criminal behavior. I can produce research that seems to bear that out, but is it true?

I don't know what this "slipstream smoke" issue is, but I do know that it is not best to be in a smoky environment where the source of the smoke is something that is laden with chemicals. Intuition (and scientific studies that back up that intuition) tells me there's a greater chance of developing some serious health issues after sucking in smoke that somes from that burning plastic chair, versus an equaly quantity of smoke from a burning cigar. Someone bitching at me because they live 3 doors down and "smell" my cigar smoke and it's a "health hazard" is just plain old CRAZY!!!

And to Doc's point - bell shaped or brick shaped curve aside. I know those individuals that smoke like a chimney and have no apparent ill effect - yet I know others that have seemingly smoke free lives that caused lung cancer. Intuition (backed up by scientific study) shows there is definitely a genetic component to disease process, and not everyone is affected by smoke in the same way. Intution leads me to the conclusion that a smoke free environment would be better than a smoke filled environment to decrease the chance that those genetically susceptible to disease are not unusually exposed.