Genotoxicity induced by iodine-131 in human cultured lymphocytes

131-radioiodine has been widely used as an effective radionuclide for treatment of patients with thyroid diseases. The purpose of this study was to investigate the genotoxic effects of iodine-131 in human cultured lymphocytes. Whole blood samples from human volunteers were incubated with iodine-131 (10, 50, 100 μCi/1.5ml) for 2 h. The lymphocytes were mitogenically stimulated to allow for evaluation of the number of micronuclei in cytokinesis-blocked binucleated cells. At the dose 100 μCi, iodine-131 induced genotoxicity by an 8.5 fold increase in the frequency of micronuclei in human lymphocytes compared with the control group.