Abstract: Through observations on the micronucleus formation in human lymphocytes in vitro and bone marrow of mice , the induced mutagenesis effect s of low dose gamma radiation combining cigarette smoking were studied. Cigarette smoking (0. 81cigarette/ ml) and low dose gamma radiation (0. 251. 0Gy) induced signficantly micronulei formation in human lymphocytes ( P < 0. 01) respectively and the significant dose2response was found. The significant higher rate of micronuleus than that of cont rol group was observed when low dose gamma radiation combining cigarette smoking was used to t reat the human lymphocytes. When low dose gamma radiation combining high concent ration cigarette smokeing (1. 5cigarette/ ml) was used to t read the mice , the significant effect s of induction and interaction on the micronucleus formation of mice bone marrow were also observed. The result sindicated that hereditary substance aberrations would be enhanced when low dose gamma radiation combined cigarette smoking.

Key words: Gamma radiation, Cigarette smoking, Induced mutagenesis effect, Micronucleus, Hereditary substance aberrations