Deposition of sidestream cigarette smoke in the human respiratory tract.

Measurement of deposition of sidestream cigarette smoke in the human respiratory tract is important for assessing the health effects of sidestream cigarette smoke. We measured the deposition fraction of sidestream cigarette smoke in 5 normal adult male volunteers using sidestream smoke at a concentration similar to that encountered indoors with smokers present. The mean deposition was 11%. These data indicate that the deposition fraction of sidestream smoke is similar to other previously studied aerosols in the same size range and is much less than mainstream smoke.