Is there any effect of volcanic eruptions of Mount Sakurajima on human lungs?--histopathological investigation and measurement of intrapulmonary particulate deposits amounts.

In order to investigate effects of volcanic eruptions of Mt. Sakurajima on human lungs, an amount of intrapulmonary particulate deposits (IPD) and histopathological changes were evaluated, using autopsied lungs of deceased residents of Kagoshima (the area affected most by the volcanic eruptions of Mt. Sakurajima, n = 66) in comparison with those of Saitama (n = 73). The amount of IPD was measured by macroscopic image analysis and by alkaline extraction. Correlation was seen in the IPD values obtained by these two methods (Spearman's correlation coefficient: 0.525). The IPD value measured through chemical digestion, which increased with age, was lower in the residents of Kagoshima (17.0 +/- 6.3 mg/g) than in those of Saitama (26.8 +/- 10.6 mg/g). This difference of IPD value between Kagoshima and Saitama residents was also observed in male, female, smoker and nonsmoker subgroups. The incidence of pulmonary emphysema was not different between Kagoshima and Saitama cases. No silicotic nodules were observed in any cases. But, the incidence of bronchial goblet cell hyperplasia and squamous metaplasia in Kagoshima was higher than that in Saitama in male cases and smoker cases. In Kagoshima cases, the incidence of squamous metaplasia was significantly higher in smokers than in nonsmokers. The synergistic influence of volcanic eruptions and cigarette smoking on human airways was suggested.