[Examination of health effects from exposure to metallic mercury in workers employed in production of chlorine and aldehyde. II. Assessment of kidney lesions].

A group under study embraced 73 workers involved in the production of acetic aldehyde, 74 workers of the department of chlorine and 13 retired workers with past poisoning by mercury. The control group consisted of 40 persons. Examinations performed in all subjects were designed mainly to assess the kidney lesions. The following results were obtained: Simple markers of kidney lesions (functions) such as urine standard examination, concentration of creatinine and glomerular filtration did not reveal clear-cut symptoms of metallic mercury nephrotoxic effect. In persons exposed to mercury an increased activity of lysosomal enzyme--beta-N-acetylglucosaminidase (beta-NAG) in urine was found. The activity of this enzyme showed correlation with actual mercury excretion in urine. A lack of correlation between beta-NAG activity and the index of cumulated urine excretion of mercury and the duration of exposure to mercury as well as low activity of this enzyme in the group of retired workers and pensioners with past poisoning by mercury suggest that the increase of beta-NAG activity is an reversible phenomenon. The value of determination of beta-2-microglobulin concentration in urine in persons currently exposed to mercury is doubtful because of the degradation of this protein resulting from urine acidification. The prolongation of secretory and excretory phase found in the renovasographic examination indicates the value of this method in the evaluation of kidney lesion in persons exposed to metallic mercury.