The present study evaluated the mitodepressive and clastogenic effects of different concentrations of Mozambique diatomaceous earth (DE) on Vicia faba L. root meristems. The effects of different DE concentrations (10, 30 and 60%) for 3, 6 and 12h have been studied on mitotic process, micronucleus frequency, pollen sterility, some biochemical parameters and ultrastructure of internal organelles. Significant dose and time dependent suppression of MI was observed. Various types of mitotic aberrations were observed in all treatments and spindle
disturbance was the most common type induced. The genotoxic effect of DE was monitored by the induction of high ratio of micronucleus and reduction in pollen fertility. As well, DE suspensions caused drastic damages on cellular organelles in dose and time dependent manner. Gene expression was changed as DNA and protein synthesis was inhibited. All present results revealed the predominance clastogenic and genotoxic effect of DE suspension on Vicia faba L,
which were concentration and time dependant.