Biopersistence of Man-Made Vitreous Silicate Fibers in the Human Lung

There is now a substantial body of experimental data on the pulmonary biopersistence of man-made vitreous silicate fibers (MMVSF), but human data are seriously lacking. Our knowledge in this field is essentially limited to a few reports of measurements of fibers retained in lung tissue sam? ples taken at autopsy from workers manufacturing these products. Three types of exposure were studied: fibrous glass, mineral wool, and refrac? tory ceramic fibers. Overall, the available data do not provide evidence for substantial long-term retention of fibers in the human lung after occupational exposure to MMVSF dusts. A word of caution, however; the amount of data supporting the previous statement is much greater for -fibrous glass than for either mineral wool or refractory ceramic fibers. There is no human data on the key question of the kinetics of pulmonary clearance of inhaled MMVSF. ? Environ Health Perspect 102(Suppl 5):225-228 (1994)