Comparative Toxicities of Different Forms of Asbestos in a Cell Culture Assay

摘要

Three forms of Union Internationale Contre le Cancer (UICC) asbestos, amosite, crocidolite, and chrysotile, were assayed for their cytotoxicity (inhibition of colony formation) in cell culture. Using embryonic human intestine-derived (I-407) and adult rat liver-derived (ARL-6) epithelial cells, the order of cytotoxicity was chrysotile>amosite>crocidolite. All three asbestos types were more toxic to I-407 than to ARL-6 cells. Chrysotile, amosite, and crocidolite were also tested for inhibition of colony formation in cultures of mouse colon-derived epithelial-like (MCE-1) cells; these cells were more resistant than the I-407 cells to all three fiber types; although similar to the ARL-6 cells in sensitivity to chrysotile and amosite, the MCE-1 cells were more sensitive to crocidolite than the ARL-6 cells. Leaching of the three asbestos forms for 3 days in sterile deionized water did not appreciably affect the cytotoxicity of I-407 or ARL-6 cells. Leaching in hydrochloric acid, however, greatly decreased the cytotoxicity of chrysotile on these cells and particularly in cultures of ARL-6 cells slightly increased the cytotoxicity of amosite and crocidolite. Leaching in deionized water altered the composition of the asbestos as revealed by release of substantial levels of Mg2+ and Ca2+ into the leaching fluid. Greater titers of these ions were released during leaching in hydrochloric acid.