Urinary N-acetyl-beta-glucosaminidase as an indicator of renal dysfunction in electroplating workers

To investigate chromium-induced renal dysfunction in electroplating workers.

A cross-sectional study was used to evaluate four biochemical markers of renal function. A total of 178 workers were divided into 3 comparable groups consisting of 34 hard-chrome plating workers, 98 nickel-chrome electroplating workers. and 46 aluminum anode-oxidation workers, who represented the reference group. Ambient and biological monitoring of urinary chromium were performed to measure exposure concentrations.

Overall, urinary chromium concentrations were highest among hard-chrome plating workers (geometric mean 2.44 microg/g creatinine), followed by nickel-chrome electroplating workers (0.31 microg/g creatinine) and aluminum workers (0.09 microg/g creatinine). Airborne chromium concentrations were also highest in the hard-chrome plating area (geometric mean 4.20 microg/m3), followed by the nickel-chrome electroplating area (0.58 microg/m3) and the aluminum area (0.43 microg/m3). A positive correlation was found between urinary chromium and airborne concentrations (r=0.54, P < 0.01). Urinary concentrations of N-acetyl-beta-D-glucosaminidase (NAG) were also highest among hard-chrome plating workers (geometric mean 4.9 IU/g creatinine), followed by nickel-chrome workers (3.4 IU/g creatinine) and aluminum workers (2.9 IU/g creatinine). The prevalence of "elevated" NAG (>7 IU/g creatinine) was significantly highest among hard-chrome plating workers (23.5%), then among nickel-chrome workers (7.1%) and aluminum workers (8.7%). Differences in beta2-microglobulin, total protein, and microalbumin were not significant.

The author's evidence indicates that NAG is an early indicator of renal dysfunction in hard-chrome plating workers.