Chronic renal effects in populations occupationally exposed to cadmium (7440439) were examined. The study group consisted of 76 males exposed to cadmium fumes and dusts in a cadmium recovery facility (group 1) and 75 males (group 2) and 109 males (group 3) employed at a nickel/cadmium battery factory. The group 2 subjects had a comparison group of 36 nonexposed males from the same facility. Comparison groups for group 1 and group 3 were not specified. Urine samples were collected and analyzed for cadmium, alanine-aminopeptidase (AAP), N-acetyl-beta-D-glucosaminidase (NAG), albumin, retinol binding protein (RBP), and beta-2-microglobulin (B2M). AAP and NAG were indicators of renal tubular tissue release into urine. Albumin was an indicator of tubular damage. RBP and B2M were indicators of impaired tubular reabsorption. Fractional clearances of albumin (FCALB), RBP (FCRBP), and B2M (FCB2M) were calculated from the data. The group 1 subjects could be classified into two groups having mean cadmium concentrations of 10.16 micrograms per gram creatinine (microg/g) (HCCG1) and 1.00microg/g. The group 2 subjects could be classified into two groups having mean cadmium concentrations of 5.88microg/g (HCCG2) and 0.84microg/g. The group 3 subjects were stratified into groups having mean urine cadmium concentrations of 16.28, 3.67, and 2.46microg/g. All group 1, group 2, and group 3 workers had significantly elevated AAP and NAG activities and albumin, RBP, and B2M concentrations. The greatest increases were seen in the group 1 subjects, which had been exposed to cadmium longer than the other groups. In group 1 subjects, FCALB, FCRBP, and FCB2M were significantly elevated in the HCCG1 subjects. Albumin concentration showed the best correlation with cadmium concentration in the HCCG1 subjects. In group 2, albumin and FCALB gave the best correlation with urine cadmium concentration. AAP and NAG activities were significantly correlated with urine cadmium concentration in the HCCG2 subjects. NAG activity was the only parameter significantly associated with urine cadmium concentration in the group 3 subjects. The authors conclude that of the measured parameters, urine albumin is the most sensitive for detecting renal damage in cadmium exposed males.