Abstract
The incidence of ferruginous bodies in the lungs was investigated by squeezing and dissolving methods in autopsies performed at random of 243 patients over 40 years of age who had been residents of the Kokuriku District. In the squeezing samples, results were positive for bodies in 64 of the total of 243 cases (26.3%); 44 of 141 (31.2%) in males and 20 of 102 (19.6%) in females. In the dissolving method, in which the specimens were obtained from the three segments described below of every right lung of 235 cases (males 136, females 99), results were positive for asbestos bodies in 88.9% of S-3, 86.4% of S-6 and 85.5% of S-10, respectively. The total positive rate of the three segments was 97.4%. All of the 61 bodies from ten patients analyzed by electron microprobe were found to be “asbestos” bodies composed of amphibole fibers.
This high incidence implies that pollution by asbestos has widely affected the residents in this area and that the number of the bodies in an unit volume of the lung tissue is more significant than the positive rate alone as the indicator of this pollution. The statistically significant higher distribution of the bodies in S-3 is probably due to greater motility of this area for the fiber-shaped asbestos dust.
