Family health hazards of passive smoking

One person smoking appears to "has nothing to do with others', is not the case, his family being passive smoking hazards. According to the World Health Organization's definition, refers to non-smokers to passive smoking is more than one day every week there is smoke exhaled by smokers inhale longer than fifteen minutes. China 71% of households, 32.5 percent of public places and 25% of the workplace, due to some "puff" and a passive place.

I'd love to see a link or reference for that. Sounds interesting.