ASSESSMENT OF RENAL DYSFUNCTION IN WORKERS PREVIOUSLY EXPOSED TO MERCURY-VAPOR AT A CHLORALKALI PLANT

Urinary albumin concentration (U-alb) and N-acetyl-beta-D-glucosaminid ase (U-NAG) and glomerular basement membrane antibodies (a-GBMs) in se rum samples were measured in 77 chloralkali workers previously exposed to mercury (Hg) vapour and 53 age matched referents. The exposure cea sed on average 12.3 (range 1-35) years before the study. The mean expo sure time was 7.9 (range 1.1-36.2) years. The mean yearly urinary Hg c oncentration (U-Hg) was 531 nmol/l. The concentrations of the urinary isoenzymes NAG A (U-NAG A) and NAG B (U-NAG B) were determined in 30 h ighly exposed subjects and 30 referents. No differences in U-alb or U- NAG, U-NAG A, or U-NAG B were found between the groups. Higher concent rations of a-GBMs were found among subjects who stopped exposure a sho rt time before the study, but there was no association between a-GBMs and U-alb. The U-NAG and U-NAG A were negatively correlated with stora ge time. The results may suggest that microalbuminuria and enzymuria r eported in subjects with ongoing exposure to Hg vapour are reversible in most instances.