Sulfuric acid submicron aerosols induce morphological changes in the central airways in the guinea pig

We examined the airway injury of the guinea pig exposed to sulfuric acid submicron aerosols (1 mg/m3). The animals were exposed to filtered air (sham control) or to submicrometer-sized sulfuric acid aerosols for 4 hr/day, 6 days/week, with sacrifices after 4 hours, 3 days, 1, 2, and 4 weeks of acid exposure. Light and electron microscopic examinations revealed that epithelial injury such as disappearance of cilia in the central airways was observed and the severity of the injury increased with exposure duration. This experimental study shows that submicrometer particles of sulfuric acid induces significant alterations in the central airways and may be involved in the incidence of asthma attack.