Davis J M, Addison J, McIntosh C, Miller B G, Niven K
Institute of Occupational Medicine, Inc. Edinburgh, Scotland, U.K.
Ann N Y Acad Sci. 1991 Dec 31;643:473-90. doi: 10.1111/j.1749-6632.1991.tb24497.x.
Six samples of tremolite of different morphological type were prepared as dusts of respirable size and used in intraperitoneal injection studies in rats. Three "asbestiform" tremolites produced mesotheliomas in almost all animals, although with significantly different tumor-induction periods. A brittle type of fibrous tremolite which, when manipulated to prepare "respirable dust," produced a sample with relatively few asbestiform fibers remaining nonetheless produced tumors in 70% of rats. Two samples of nonfibrous tremolite produced respirable dust samples containing numerous elongated fragments with aspect ratios greater than 3:1, which therefore fitted the definition of respirable fibers. Both these samples produced relatively few tumors, although one had more long "fibers" than did the brittle tremolite that produced 70% of tumors. This study has therefore demonstrated that different morphologic forms of tremolite produce dusts with very different carcinogenic potential. Carcinogenicity does not depend simply on the number of elongated particles injected, and we need to develop methods of distinguishing carcinogenic tremolite fibers from relatively innocuous tremolite dusts, with similar numbers of elongated particles of similar aspect ratios.
制备了六个不同形态类型的透辉石样本，将其制成可吸入大小的粉尘，用于大鼠腹腔注射研究。三种“石棉状”透辉石在几乎所有动物中都诱发了间皮瘤，尽管肿瘤诱导期明显不同。一种脆性纤维状透辉石，在制备“可吸入粉尘”时，尽管剩余的石棉状纤维相对较少，但仍在70%的大鼠中诱发了肿瘤。两个非纤维状透辉石样本制成的可吸入粉尘样本含有大量长宽比大于3:1的细长碎片，因此符合可吸入纤维的定义。这两个样本诱发的肿瘤相对较少，尽管其中一个样本的长“纤维”比诱发70%肿瘤的脆性透辉石更多。因此，这项研究表明，不同形态的透辉石产生的粉尘具有截然不同的致癌潜力。致癌性不仅仅取决于注入的细长颗粒数量，我们需要开发方法，将致癌性透辉石纤维与具有相似长宽比且数量相似的细长颗粒的相对无害的透辉石粉尘区分开来。
