Murai Y, Kitagawa M, Matsui K, Koizumi F, Miwa A
Department of Pathology, Toyama Medical and Pharmaceutical University, Japan.
Arch Environ Health. 1995 Jul-Aug;50(4):320-5. doi: 10.1080/00039896.1995.9935961.
We examined the types and sizes of 100 asbestos fibers in lung tissue obtained from 9 lung-cancer cases (5 autopsy and 4 surgical) with more than 10(4) asbestos bodies per 5 g of wet lung tissue, asbestos bodies in histological sections, and the history of occupational asbestos exposure. Evaluation of asbestos fibers by transmission electron microscopy (2,000 x magnification) revealed that most fibers were longer than 3 microns (96%) and were thicker than 0.1 micron (93%). The analytical conditions we used enabled us to identify 99.7% of all asbestos fibers as being amphibole asbestos. Crocidolite fiber, which was found most frequently (73.1%), was the predominant type of fiber found in 8 of the 9 cases; crocidolite was followed by amosite (21.7%), which was the predominant type found in the remaining case. Crocidolite fibers were thin and had a high aspect ratio (mean diameter = 0.23 micron, mean aspect ratio [length/diameter] = 85.5). Amosite fibers were long, and they also had a high aspect ratio (mean length = 21.8 microns, mean aspect ratio = 66.4). It has been suggested that such fibers with a high aspect ratio are strongly carcinogenic to pulmonary parenchyma. Review of our previous and present data with respect to the ratio of amosite to crocidolite fibers in groups of subjects who had various diseases revealed that this ratio was relatively constant in some occupations. The more predominant fibers found were crocidolite in insulation workers and amosite in railroad workers. The ratio of amosite to crocidolite fibers should be considered in tissue-burden studies.
我们检查了从9例肺癌患者（5例尸检和4例手术）的肺组织中获取的100根石棉纤维的类型和大小，这些患者每5克湿肺组织中石棉小体超过10⁴个，还检查了组织切片中的石棉小体以及职业性石棉接触史。通过透射电子显微镜（放大2000倍）对石棉纤维进行评估发现，大多数纤维长度超过3微米（96%），直径超过0.1微米（93%）。我们使用的分析条件使我们能够将所有石棉纤维的99.7%鉴定为闪石类石棉。最常发现的青石棉纤维（73.1%）是9例中的8例的主要纤维类型；其次是铁石棉（21.7%），是其余病例中的主要纤维类型。青石棉纤维细且长径比高（平均直径 = 0.23微米，平均长径比[长度/直径] = 85.5）。铁石棉纤维长，长径比也高（平均长度 = 21.8微米，平均长径比 = 66.4）。有人提出，这种长径比高的纤维对肺实质具有强烈致癌性。回顾我们之前和现在关于患有各种疾病的受试者群体中铁石棉与青石棉纤维比例的数据发现，在某些职业中这个比例相对恒定。绝缘工人中发现的主要纤维是青石棉，铁路工人中是铁石棉。在组织负荷研究中应考虑铁石棉与青石棉纤维的比例。
