[Selected markers of subclinical renal damage in men occupationally exposed to mercury vapours].

The concentrations of albumin, IgG, transferrin, retinol binding protein (RBP), alpha-1-microglobulin (alpha-1-m) and beta-2-microglobulin (beta-2-m) were determined in urine of 83 males 21 to 60 years old (Mean = 41.2 +/- SD = 10.7) with a history of occupational exposure to metallic mercury vapours from 7 months to 37 years (Mean=16.3 +/- 10.9) and in 30 males without this exposure by using the nephelometry (Behring's antibodies, references and controls). The weighted mean of mercury concentrations in air was from 0.028 to 0.037 mg m(-3). The urinary level of mercury was determined by using the atomic absorption spectrometer Coleman Mercury Analyzer Mas-50, Perkin-Elmer USA, in alpha=253.7nm. The detection limit of the analytical procedure of determination of mercury in urine was 10 microg/dm3 and in blood was 4 microg Hg/dm3. Workers were divided into three groups depending on the duration of exposure: I/. 30 males with a short history of exposure to Hg0 (7 months to 9 years) (4.2 +/- 2.8), II/. 18 males exposed from 10 to 20 years (14.5 +/- 3.3) and III/. 35 males with a history of long exposure (21 to 37 years) (27.5 +/- 4.0) following three groups were divided depending on the degree of exposure: 1/. 32 males with concentrations of mercury in urine < 50 microg Hg/ dm3 (30.5 +/- 10.7) aged 26 to 59 years (45.5 +/- 8.0) and exposed to Hg0 from 7 months to 37 years (18.1 +/- 10.8); 2/. 41 males with concentrations of mercury in urine 51 to 150 microg Hg/dm3 (86.1 +/- 24.3) aged 21 to 60 years (39.8 +/- 10.8) and exposed to Hg0 from 7 months to 35 years (15.9 +/- 10.8) and group 3/. 32 males with concentrations of mercury in urine 151 to 260 microg Hg/dm3 (211.4 +/- 37.1) aged 21 to 56 years (35.5 +/- 13.1) and exposed to Hg0 from 7 months to 30 years (9.1 +/- 8.8). Occupational exposure to mercury vapours influenced urine mercury concentration and urine excretion of determined proteins: albumin, IgG, transferrin, alpha-1-microglubulin and beta-2-microglubulin. In the group of workers exposed to mercury vapours from 7 months to 9 years, statistically significance elevation of alpha-1-m and beta-2-m [alpha-1-m by 67.5% (p<0.05) and beta-2-m by 66.7%] according to the control group was observed. Albumin urine concentrations was highest in the group of exposed workers with mean urine mercury concentration > 150 microg/dm3, 2-times higher (p<0.05) than in the control group as well as in the group workers exposed to mercury with mean urine mercury concentrations 51 to 150 microg/dm3 (p<0.05) and more than 3-times higher than in the workers with mean urine mercury concentrations < or = 50 microg/ dm3. Mean IgG and transferrin urine concentrations were higher [IgG 2.6-times higher (p<0.05), transferrin 7.5-times higher (p<0.05) according to the control group] in the group of workers with urine mercury concentrations > 150 microg/dm3. Mean alpha-1-m and beta-2-m urine concentrations were highest in group of workers with urine mercury concentration > 150 microg/dm3 [alpha-1-m by 82% (p<0.05) and beta-2-m by 289% (p<0.01)]. Moreover, a positive correlation between mercury urine concentration and alpha-1-m (r=0,33), as well as between mercury urine concentration and albumin (r=0,31) and IgG (r=0.30) also were observed. Values of "r" between mercury urine concentration and albumine (r=0.46), IgG (r=0.46) and transferrin (r=0.42) were highest in group of workers exposed to mercury vapours from 10 to 20 years. Albumin, transferrin and IgG urine concentrations, as well as alpha-1-m and beta-2-m urine concentrations were statistically significantly higher in the group of workers with > 150 microg Hg/dM3 urine concentration. In conclusion, determination of urine proteins, as a markers of early subclinical renal damage may be useful in monitoring occupational exposure to mercury vapours, especially in the group of workers with higher values of urine mercury concentrations.