Evaluation of biological indicators of body burden of cadmium in humans

Abstract

The cadmium content in the left kidney (KCd) and concentration in the liver (LCd) were measured in vivo in 51 adult male workers actively employed at a cadmium plant and in 10 nonexposed controls. Cadmium levels in blood (BCd), urine (UCd) and hair (HCd) were also obtained for each subject. When the workers were classified on the basis of urinary excretion of β 2-microglobulin, albumin and total protein, 33 workers were judged to have normal renal function, and 18 workers were found to have renal dysfunction. In the two groups of industrial workers the mean value for each biological index of cadmium exposure was statistically elevated when compared with the mean value for the controls. Examination of the interrelationships among KCd, LCd, BCd, UCd and HCd provided the following conclusions: (a) Only on a group basis was UCd correlated (r = 0.61) with KCd in workers with normal renal function; (b) BCd was corrected with LCd in workers with normal kidney function (r = 0.53) and in workers with renal dysfunction (r = 0.68); (c) HCd had the largest variability of the biological indices and was unrelated to body burden; (d) KCd and LCd were positively correlated in workers with normal kidney function, whereas KCd decreased with increasing LCd in workers with renal dysfunction. This study demonstrates that the qualitative nature of the relationship of BCd, UCd and HCd (biological indices of exposure) with KCd and LCd (body burden) is not sufficiently quantitative for predicting the body burden of an individual worker.