If the periodic table had been based on questionnaires every person on the planet would have an element named after him.
If you want to have an idea of what trash the "science" on passive smoking really is, just watch this video on the questionnaire used for the Multi-centre Study of the IARC (International Agency for Research on Cancer, WHO). The questionnaire is considered the best of its kind, so imagine the rest. This is the bilge upon which any and all smoking bans in the world rest — and this is the "public health" institution today that tells you that "smoking kills." For more laughs download the complete questionnaire at the link below and read it yourself.