EFFECTS OF EXPOSURE TO ELEMENTAL MERCURY ON THE NERVOUS-SYSTEM AND THE KIDNEYS OF WORKERS PRODUCING NATURAL-GAS

Early signs of alterations in renal and neurological functions were st udied in three groups of workers who were exposed to different levels of mercury that were below the current biological exposure index of 35 mu g/g creatinine. There were no differences among the three study gr oups with respect to either motor nerve conduction velocity or tremor frequency spectra of physiological tremors. Also, no significant corre lations were found between the results of the neurological tests acid any of the present or historical biological monitoring data. In contra st, N-acetyl-beta-D-glucosaminidase was increased significantly in the group with the higher exposure, compared with either the lower-exposu re or control groups. N-acetyl-beta-D-glucosaminidase was correlated s trongly with mercury concentration in urine and was correlated weakly with historical biological monitoring data; however, there was no corr elation with duration of exposure. These results suggest that after ex posure to mercury at levels below the biological exposure index, a tra nsient increase in N-acetyl-beta-D-glucosaminidase can be observed, bu t is not an early indicator of developing renal dysfunction.