[Experimental studies of the effects of atmospheric pollutants]

Experimental studies in man are an indispensable complement to epidemiological studies and experimental studies on animals. They aim at understanding the mechanisms of action of the main pollutants and at knowing their thresholds of triggering of the acute effects on the respiratory system. The studies made in man involve controlled exposure to different atmospheric pollutants, with measurement of the functional respiratory repercussions, studies of modification of the cells in broncho-alveolar lavage, as well as experimental protocols that combine inhalation of allergen and exposure to atmospheric pollutants by allergic subjects. The main results that are available are reported to distinguish those from normal subjects and those who are allergic. More recent protocols are based on exposure to concentrations that are close to atmospheric concentrations or those that are met in work places. The main data in the literature are reported in this journal and concern SO2 acid aerosols, dioxides of nitrogen, ozone and diesel particles. Pathogenic hypotheses concerning the undesirable effects of atmospheric pollutants on the respiratory system are considered.