In-vitro toxicity evaluation of ten particulate materials in tracheal organ culture. Contractor report, June 1985-June 1987

This study was conducted to explore alternative toxicological testing methods for assessing the potential health hazard of particulate materials. The in vitro toxic effect of eight particles (graphite fibers, polycrystalline iron whiskers, aluminum dust, nickel-coated graphite fibers, brass dust, Printex L carbon black, micro-260 synthetic graphite dust and KS-2 natural graphite dust) was evaluated on the upper respiratory epithelium of hamster tracheal organ cultures based on microanatomical and histomorphometric changes. Tissue changes induced by the test articles were compared to changes that occurred in tracheal organ cultures exposed to crocidolite asbestos (positive control) and glass beads (negative control), in addition to untreated explants. The relative toxicity of each test particle was characterized base on qualitative histopathologic and morphometric differences relative to the positive and negative controls. Crocidolite asbestos and Ni-coated graphite were the most reactive in this study. Iron whiskers, aluminum dust, and KS-2 graphite caused an intermediate level of tissue response, while the remaining substances did not cause significant tissue responses compared to control explants. The most cytotoxic materials were brass dust and Ni-coated graphite.