Usefulness of determining urinary markers of early renal damage for monitoring nephrotoxicity during occupational exposure to mercury vapors

: Using nephelometry, concentration of albumin, IgG, transferrin, retinol binding protein (RBP) alpha 1-microglobulin were determined in urine of 83 males with history of occupational exposure to metallic mercury vapours from 0.6 to 37 years, and in 30 non-exposed males. The weighted average of mercury air concentrations was 0.028 mg/m3. Duration of occupational exposure to mercury vapours did not elevate urine excretion of proteins. The urine concentration of proteins in question were higher (especially beta 2-m) in workers with urine mercury concentration between 51 and 150 microliter-1 and highest in workers with urine mercury concentrations above 150 micrograms l-1 and the differences were significant. In addition, a positive correlations between urine mercury concentrations and alpha 1-m (r = 0.33) as well as between urine mercury concentration and albumin (r = 0.31) were observed. In conclusion, the determination of proteins in urine as markers of early renal damage may be useful for monitoring occupational exposure to mercury vapours, especially in the group of workers with elevated values of urine mercury concentrations.