Asbestos body phagocytosis by human free alveolar macrophages.

Phagocytosis of asbestos bodies by human free alveolar macrophages (FAMs) was documented employing light microscopy. This process was more carefully studied utilizing scanning electron microscopy (SEM) which demonstrated morphological and surface membrane changes in FAMs following phagocytosis of asbestos bodies. FAM viability was also evaluated following 24--72-h incubation of cells with asbestos bodies at a final concentration of 250 micrograms/ml. Slight, but significant, cytotoxicity was observed following the initial 24-h culture period (P = 0.032, paired, 2-tailed t-test). No further cytotoxicity was observed, however, when cells were further incubated for 48-h and 72-h intervals (P greater than 0.05 in all instances). These studies demonstrate asbestos bodies are readily phagocytized by cultured FAMs, and are only slightly cytotoxic to these human lung cells.