Renal function in relation to low levels of cadmium exposure in a group of smelter workers

Blood and urine samples were obtained from 274 smelter workers and urine samples from 48 controls. Cadmium, beta 2-microglobulin, and creatinine were estimated in blood and urine, and total protein in urine. Concentrations of cadmium in urine (mean 2.0 nmole/mmole creatinine) and blood (mean 21.8 nmole/L) observed in the smelter workers confirmed that this group had absorbed more cadmium than the general population, but less than most other occupationally exposed groups studied. Mean beta 2-microglobulin in urine was not significantly different in the smelter workers and the controls. The mean total protein in urine was 20% higher in the smelter workers, a difference which was significant (p congruent to 0.01). There was no consistent picture within the smelter workers of a relationship between history of cadmium exposure and the effect measures of beta 2-microglobulin in urine and blood, total protein in urine, creatinine clearance and relative beta 2-microglobulin clearance. Small but significant positive correlation coefficients were observed between cadmium in urine and beta 2-microglobulin in urine (r = 0.13), total protein in urine (r = 0.23) and beta 2-microglobulin clearance (r = 0.15), although these may be artifactual.