Health effects of volcanic ash of Mt. Sakurajima; studies on calf lung and loggers

为了研究火山灰对健康的影响。樱岛，以下研究进行。1.粉尘引起的肺部变化，在伐木工人谁是最频繁和最严重的火山灰暴露。虽然他们的工作环境中的悬浮颗粒物（SPM）的水平有很大的不同，根据工作领域，所有组的伐木工人表现出较低的呼吸道症状的患病率和平均肺功能正常。胸片检查未发现尘肺病例。这些最高暴露组的结果表明，火山灰不太可能是普通人群呼吸道疾病的主要原因。研究了火山灰对健康影响研究中呼吸道症状问卷调查和呼吸道疾病标准的可靠性，以确定火山灰暴露的季节性影响。用ATS-DLD对380名接触火山灰的妇女进行了春、夏两季的重复调查。结果表明，症状较重或出现频率较高的患病率，以及多项综合诊断标准对呼吸系统疾病的诊断在季节上相对稳定。这些发现表明，通过限制分析仅与常见症状相关的问题，季节性变化将最小化，并且将获得更稳定的结果。通过对火山灰暴露区小牛肺的元素组成分析，探讨小牛肺作为火山灰生物学指标的可行性。在各种元素中，肺组织中的硅含量与暴露时间的相关性最好，并且在来自最高暴露区的小牛肺中显示出最高的平均值。为了证实这些发现，目前正在进行进一步的研究。

In order to investigate the health effects of volcanic ash of Mt. Sakurajima, following studies were conducted.1. Dust induced pulmonary changes were searched in loggers who are exposed most frequently and heavily to volcanic ash. Although the levels of suspended particulate matter (SPM) of their working environment differed a great deal depending on the work areas, all the group of the loggers showed low prevalences of respiratory symptoms and average pulmonary functions were normal. No case with pneumoconiosis was found by the chest roentogenogram examination. These results among the highest exposed group suggest that volcanic ash is not likely to be a major cause of respiratory diseases for the general population.2. Reliability of the questinnaire survey for respiratory symptoms and the criteria for respiratory diseases in the srudy of the health effects of volcanic ash was examined in order to roleout the effects of seasonality of ash exposure. Using ATS-DLD to 380 women exposed to volcanic ash were surveyed repeatedly in both spring and summer. Results showed that prevalences of relatively severe symptoms or symptoms with higher frequencies, and diagnosis of respiratory diseases by combined multiple item criteria were relatively stable over the seasons. These findings indicate that by limiting analysis to questions related to frequent symptoms only , seasonal variation would be minimized and more stable results would be obtained.3. The availability of calf lung as a biological index of volcanic ash was examined by analyzing the elemental composition of lungs of cals bled in the area exposed to volcanic ash. Among the various elements, the content of silicon in the lung tissue was best correlated with the duration of exposure and showed the highest average value in the lungs of calf from highest exposed area. To confirm these findings, further study is currently under way.