I am amazed at what is passed off for science these days. We had a saying in the military: "If you were run off the road and crashed into a tree that had a beer can sitting next to it, it would be considered a alchohol related accident." It seems to be the same argument for smoking.
I typed in "second hand smoke" and "study" and couldn't find a single study on the subject. I found several sites that were pro/con and all of them referenced studies that were not linked. This argument is so abstract that it is pathetic. One site, did describe the methods used to attain the data and I found it to be anything but science. A questionare is not science. A study of the health of smoker's spouses vs non-smokers is not science (BTW... that one showed no difference). Science would tell you why this is happening, not that the person said they breathed second hand smoke and that's what did it.
I'm getting pretty disgusted with the level of government meddling in some of these things. It's one of the reasons why I'd prefer abortion be legal: If it were illegal because the baby had rights then any consumption of alchohol, cigarettes, lack of excercise, sudden movements or anything else that would put the baby at risk would be considered child abuse. That's the legal system the world is moving to. The super-nanny system.