Renal impairment caused by chronic occupational chromate exposure

Abstract

Purpose: To determine the nephritic toxicity of chromate after chronic occupational exposure.

Methods: The environmental contamination was assessed by measuring the chromium (Cr) in 8-h airborne sampler. The integrated level of Cr was determined by Cr concentrations in the whole blood (WB-Cr) and the urine (U-Cr). The renal glomerular and tubule impairment was evaluated by determination of cystatin C (Cys-C) in the serum and microalbumin (mALB), urinary beta(2)-microglobulin (β(2)M), N-acetyl-beta-D-glucosaminidase (NAG) activity in the urine.

Results: The mean occupational exposure time to Cr was 12.86 years with average daily air level of 27.13 μg/m(3) comparing to 0.11 μg/m(3) of the background level. The WB-Cr and U-Cr were 23.49 μg/L and 17.41 μg/g creatinine (Cre), respectively in the chromate-exposed workers comparing to 3.32 μg/L and 1.52 μg/g Cre in the controls. The serum Cys-C and urinary mALB were significantly increased in the chromate-exposed workers. Exposure to Cr seems to induce an enhanced level of urinary NAG activity and β(2)M concentration. The increased serum Cys-C concentration was positively correlated with the level of serum Cre. The U-Cr was positively correlated to the concentrations of urinary mALB, β(2)M, and the activity of NAG.

Conclusions: Chronic occupational exposure to chromate causes comprehensive renal impairment though more severity could occur in the tubule than in the glomerular.