Mucosal pathology of the eustachian tube after exposure to sulfur dioxide

We studied the mucosal pathology present in the eustachian tubes of guinea pigs following exposure to sulfur dioxide. Secretory sthenia but with slight deterioration of ciliary activity was observed in the mucosal samples examined. Our data have shown that 24-h exposure to 300 ppm sulfur dioxide does not cause otitis media with effusion in the guinea pig since active ciliary function will prevent any secretions produced from stagnating in the tympanic cavity.