Fiber Analysis in Lungs of Residents of a Japanese Town with Endemic Pleural Plaques

Abstract The authors analyzed various types of fibers in lung-tissue samples, which were obtained from 50 cases (46 surgical resections and 4 autopsies) at Kumamoto-Minami Hospital in Matsubase, where the occurrence of pleural plaques is endemic. Lung cancer necessitated surgical resection in 44 cases. Eleven of the 50 cases were residents of Matsubase; 15 resided in the region around the town, where the frequency of pleural plaques was slightly higher; and 24 cases lived in a region with normal plaque frequency. The number of anthophyllite fibers in the lungs of town residents was significantly higher than in residents of the region with normal plaque frequency. In 6 cases, the authors found accompanying pleural plaques, and the anthophyllite fiber count in the lungs in these cases was significantly higher than in cases without plaques. In addition, the anthophyllite fiber counts in 2 cases with severe plaques were significantly higher in 4 cases with only mild plaques. These results suggested that antho...