Well, non-smokers needed a reason to ban smoking, since "I don't like it" doesn't really suffice in the USA (or at least, it didn't used to.) So the myth of "deadly" second hand smoke was cooked up by the political left, and here we are twenty five years later.
Folks, if you do a little research, there's no evidence to suggest that walking past a smoker is more dangerous than walking past a farter. Before you start gagging, coughing and screaming "OMG the poison!", perhaps you should re-examine the evidence. You may be surprised how duped we have become as a society.
While I agree that walking by a smoker on the sidewalk will not harm you the evidence that living with a smoker is damaging is overwhelming. I think it's also reasonable to believe that working in a smoke filled office / shop for years would also be dangerous. From my years of working in the operating room I've seen the lungs of nonsmokers that certainly looked as if they had smoked because they lived with a smoker. Now with all that said I still firmly believe that smoking is your right and that there needs to be a reasonable accommodation for workers.
About the farts not being dangerous. Obviously you have not been around my mates and I after the atomic wings at Quaker steak and lube.