Scanning electron microscopic evaluation of the alterations induced by polluted air in the rabbit bronchial epithelium.

With the aim of evaluating the influence of polluted air on the respiratory epithelium, ten New Zealand white rabbits, from a group of fifteen kept in the country, were transported to a site located in a metropolitan area. After 40 days, all the rabbits were killed, and the bronchial mucosa studied by scanning electron microscopy (SEM). In the animals exposed to polluted air, the ciliated cells, less numerous than in normal cases, show an evident decrease in the number and size of the cilia, exposing apical microvilli. It is therefore possible to hypothesize that a part of the non-ciliated cells is made up of cells that have lost their cilia. The number of non-ciliated elements and the amount of mucous secretion appear to have noticeably increased. The considerable response of the respiratory epithelium to inhaled agents appears to be confirmed, as is the irritant effect of polluted city air.