SILICA-INDUCED MICRONUCLEI AND CHROMOSOMAL-ABERRATIONS IN CHINESE-HAMSTER LUNG (V79) AND HUMAN LUNG (HEL-299) CELLS

Silica is one of the most abundant and widely used mineral groups. A l arge number of workers are potentially exposed to one or more forms of silica. Therefore, the potential carcinogenic hazard of silica to the exposed workers is of great concern. This study examines the genotoxi c potential of silica with the micronucleus and chromosomal aberration assays using cultured Chinese hamster lung fibroblasts (V79) and huma n embryonic lung (Hel 299) cells. One-day-old cultures were treated wi th two types of silica, Min-U-Sil 5 and Min-U-Sil 10, for 24 h at conc entrations of 40, 80, 160 and 320 mu g/cm(2). Both Min-U-Sils at 160 a nd 320 mu g/cm(2) induced micronucleus formation in V79 and Hel 299 ce lls. In V79 cells, a significant increase in the micronucleus frequenc y was also found with 40 and 80 mu g/cm(2). However, the chromosomal a berration frequency was unaffected by either Min-U-Sil 5 or 10 treatme nt of V79 or Hel 299 cells. Results indicated that silica, in differen t particle sizes, was capable of inducing micronuclei but not chromoso mal aberrations in cultured animal and human lung cells and suggested that V79 cells were relatively more sensitive to silica than Hel 299 c ells.