Renal impairment caused by chronic occupational chromate exposure.

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.