Absence of tubular proteinuria following environmental exposure to chromium

Certain chromium compounds are known to be nephrotoxic, but renal damage from long-term environmental or occupational exposure to chromium has not been documented. To detect possible preclinical renal damage, we tested the urine of 55 lifelong residents of an area contaminated with chromium landfill. The levels of four proteins were determined in urine samples: (1) human intestinal alkaline phosphatase, (2) tissue nonspecific alkaline phosphatase, (3) N-acetyl-beta-D-glucosaminidase, and (4) microalbumin. No elevated levels of proteins were found, and there were no significant correlations between urine protein and urine chromium concentrations. We concluded that long-term environmental exposure to chromium dust did not lead to tubular proteinuria.