Sister-chromatid exchanges (SCEs) were analyzed using peripheral lymphocyte from 38 persons (20 men and 18 women) who had been exposed to environmental cadmium (Cd), and 9 controls (7 men and 2 women). Correlations between SCE rates and urinary Cd-concentrations were done. There were no significant differences in SCE rates between the Cd-polluted and nonpolluted groups. There were no significant correlations between SCE rates and urinary Cd concentrations.