A quantitative and histological study on pulmonary effects of asbestos exposure in general autopsied lungs

We demonstrated the distribution of asbestos bodies (ABs) in the lungs of 656 consecutive autopsy cases by KOH digestion method. Nine patients including one case with asbestosis had more than a thousand ABs. These patients were all blue-collar workers except the two cases without occupational history. The tissue sections for these patients revealed the constant presence of more than one or two ABs. In addition, five of these subjects had parenchymal and/or peribronchiolar fibrosis. On the basis of the result of AB counts, we selected 17 subjects for enumeration and typing of asbestos fibers (AFs). The number of AFs roughly correlated with that of ABs. However, the ratio of AFs to ABs ranged from 13 to 3,700. The fiber types in our selected subjects were almost always amphibole (crocidolite, amosite). These findings indicate that modest or secondary exposure to asbestos causes virtual asbestosis to several subjects among the general population.