Population burden of lung cancer due to environmental tobacco smoke.

The population burden of lung cancer due to environmental tobacco smoke is significant because a large fraction of the population is exposed. The risks are, of course, lower than those to smokers themselves; but smoking is self-inflicted, passive smoking is involuntary. Making various assumptions, the proportion of lung cancer cases among non-smokers that could reasonably be attributed to environmental tobacco smoke can be calculated to be about 20-30% in western countries. Thus, non-smokers in the society could benefit considerably from diminishing exposures to other people's smoke.