Analysis of Tissue Mineral Fiber Content
Mineral fibers may be identified in the lungs of most individuals from industrialized societies. When present in excessive amounts, the accumulation of these fibers may result in several diseases. At lower levels, there is an increased risk of mesothelioma and pleural plaques, while at even higher levels, there is an increased risk of lung cancer and asbestosis. Procedures for digesting lung tissue have been designed that permit the analysis and quantification of retained mineral fibers. Analytical electron microscopy provides the means to detect the smallest and thinnest fibers and to determine fiber types. The most common fiber types associated with asbestos-related diseases in the United States are commercial amphibole fibers (amosite or crocidolite), and the levels of these fibers have been shown to have decreased in lung tissue samples over the last two decades. Other mineral fibers, such as erionite and Libby amphibole fibers may also be a cause of asbestos-related diseases, especially mesothelioma. As fiber burdens continue to decrease and the relative percentage of diseases not caused by asbestos increases, analysis of tissue mineral fiber content will play an increasingly important role in the determination of disease causation.
