The mucociliary clearance system is a first line of defense against inhaled agents, and so its
compromise can adversely affect health. The purpose of this paper is to provide a review of
data on the effect of in vivo air pollutant exposures on the clearance of test particles from
airways. Data from both animals and humans are compared whenever possible, so that
estimates of human health effects may be made. Mechanisms of action are also discussed,
presenting the view that for low level exposures, changes in secretions are probably …