FLOW CYTOMETRIC ANALYSIS OF MICRONUCLEUS INDUCTION IN MICE BY INTERNAL EXPOSURE TO CS-137 AT VERY-LOW DOSE-RATES

Internal radiation from Cs-137, intraperitoneally injected into mice, induced chromosome damage seen as micronuclei in erythrocytes of perip heral blood harvested 72 h after injection and analysed With flow cyto metry. The retention of injected Cs-137 activity was determined and th e absorbed doses obtained from the beta-radiation of Cs-137 were calcu lated for the whole bodies and bone marrow of the treated mice. The ab sorbed doses during the most relevant period for micronucleus inductio n were 2.7-18.3 mGy per day. The dose to the bone marrow during the sa me period was calculated to be 6-44 mGy per day. A linear dose respons e relationship was found.