Validation of asbestos exposure in mesothelioma cases clustered among residents near an asbestos cement pipe production factory and risk estimation of deaths due to mesothelioma.

我们获得了72例间皮瘤患者或其家属的胸膜组织、完整的肺组织或胸部CT片，他们接受了我们的访谈研究并给予了书面知情同意。所有病例都是居住在久保田石棉水泥管道生产厂附近的居民。采用免疫组织化学方法对胸膜组织进行复查，包括间皮瘤阳性标记和肺癌阴性标记。在31例诊断为间皮瘤的患者中，仅有1例(3.0%)经组织学复查证实为其他疾病。三位放射学专家一致认为，所有胶片的发现与通常在间皮瘤病例中观察到的结果一致。他们指出，23.7%的研究对象存在胸膜斑块。12例受试者肺组织石棉小体计数成功。其中一半的数字远低于职业上接触石棉的工人，但高于没有接触任何种类石棉的工人。五名受试者的肺部石棉纤维浓度可以计算出来。所有研究对象均发现青石棉纤维。然而，我们无法得出明确的结论，因为这些受试者可能是职业接触或家庭接触。这些结果表明，误诊比我们想象的要低得多，工厂附近的居民发生了邻里接触石棉的情况。在我们采访的178名患有石棉相关疾病的居民中，有73人于1995年1月1日至2006年底死于间皮瘤，他们居住在距离工厂1500米以内的地区。300米范围内，间皮瘤的SMR显著增加，男性高达14，女性高达41。女性SMR的显著升高延伸到距离核电站1500米的地方。

We obtained pleural tissue having mesothelioma, intact lung tissue or chest CT films from 72 mesothelioma cases or their families, who granted our interview study and gave a written informed consent. All cases were residents who had lived near an asbestos cement pipe production plant, Kubota. Pleural tissues were provided for re-examination for pathological diagnosis using an immunostaining assay, which consisted of both positive makers for mesothelioma and negative ones for lung cancer. Of 31 cases whose diagnosis was mesothelioma, only one case (3.0%) turned out to be a different disease by re-examination of the tissue. Three radiographic specialists agreed that all films fad findings consistent with those commonly observed in mesothelioma cases. They indicated an existence of pleural plaque in 23.7% of the study subjects. The number of asbestos bodies in the lung tissue was successfully counted in 12 subjects. Half of them showed the number which was much lower than that of workers exposed to asbestos occupationally but higher than in persons not exposed to asbestos of any kind. Asbestos fiber concentrations in the lung could be counted in five subjects. Fibers of crocidolite were found in all study subjects. However, we could not obtain definite conclusions because these subjects were likely to be exposed occupationally or domestically.These results suggest that misdiagnosis is much lower than we had imagined and neighborhood exposure to asbestos occurred among residents near the plant. Of 178 residents with asbestos-related diseases with whom we made an interview, 73, who lived in the area within 1, 500 meters from the plant, died from mesothelioma after Jan, 1, 1995 till the end of 2006. SMRs of mesothelioma increased significantly as high as 14 among men and 41 among women within 300 meters. A significant elevation of SMRs in women extended as far as 1, 500 meters way from the plant.