GENOTOXICITY OF SELECTED PESTICIDES IN THE MOUSE BONE-MARROW MICRONUCLEUS TEST AND IN THE SISTER-CHROMATID EXCHANGE TEST WITH HUMAN-LYMPHOCYTES IN-VITRO

Selected pesticides (aldicarb, 1,3-dichloropropene, methidathion, para thion, triadimefon, vinclozolin) were tested for their clastogenic and aneugenic activities in the mouse bone-marrow micronucleus (MN) test in vivo and for their sister-chromatid exchange-inducing activities in human lymphocytes in vitro in the presence and absence of an exogenou s metabolizing system from rat-liver S9. 1,3-Dichloropropene significa ntly increased the frequencies of micronucleated polychromatic erythro cytes (PCE) in bone-marrow cells of female mice from 3.3 MN/1000 PCE t o. 15.3 MN/1000 PCE (187 mg per kg body weight). 1,3-Dichloropropene ( 100 mu M) induced 16.0 SCE/metaphase after 24 h of incubation as compa red with the basal rate of 11.2 SCE/metaphase (-S9) and of 15.4 SCE/me taphase as compared with 10.5 SCE/metaphase of the control (+S9). Thes e values were statistically significantly different from each other. T he other pesticides tested did neither increase the rate of micronucle i significantly in polychromatic erythrocytes in male nor in female an imals. Aldicarb and methidathion induced a significant increase in SCE s in human lymphocytes in vitro only without the metabolic activating system: aldicarb, 5 mu M, 24 h incubation: 15.5 SCE/metaphase; control : 12.6 SCE/metaphase; methidathion, 100 mu M, 24 h incubation: 15.8 SC E/metaphase, control: 11.1 SCE/metaphase. Parathion, triadimefon and v inclozolin did not have any SCE-inducing effects.