Kidney cadmium as compared to other markers of cadmium exposure in workers at a secondary metal smelter.

Abstract

The aim of the study was to evaluate whether cadmium concentrations in kidney (K-Cd), blood (B-Cd) or urine (U-Cd) could reveal previous occupational cadmium exposure at a metal smelter. The study included 90 smelters and 35 controls (B-Cd and U-Cd determination). In a subgroup (N = 33), K-Cd was also determined. B-Cd (median 4.6; range 0.5-53 nmol/L), U-Cd (0. 29; 0.04-1.9 micromol/mol creatinine) and K-Cd (14; 3-61 microg/g wet weight) were similar to reported concentrations in the general Swedish population. In the subgroup, significant associations (P<0. 001) were obtained between B-Cd and K-Cd (r = 0.70), U-Cd and K-Cd (r = 0.60) and between U-Cd and B-Cd (r = 0.62). Multiple regression analyses revealed smoking as the major predictor of K-Cd, B-Cd, and U-Cd. B-Cd and U-Cd were both associated with the duration of employment at the smelter. There was no statistically significant evidence of previous occupational exposure at the smelter from measurement of K-Cd.