The influence of amosite asbestos exposure on lung permeability

The effect of amosite asbestos on permeability of the blood/air barrier in the lung was studied using an acute animal model. The ultrastructural tracer selected for the study was horseradish peroxidase which was given intravenously in animals that had been exposed intratracheally to asbestos. The acute period of study was either 1/2, 1, 2, 3, or 4 hr, or 1-7 or 14 days postexposure. The barrier in the normal lung was at the level of the alveolar epithelial lining. Leakage of exudate and tracer occurred through the altered barriers following asbestos exposure and the extent of leakage related directly to the degree of alveolitis and the asbestos present in the area. A trend toward recovery of the barrier occurred with the reestablishment of a more normal-appearing epithelial lining during the second week postexposure.