Renal function of chloralkali workers after the cessation of exposure to mercury vapor.
OBJECTIVE
The aims of the study were to assess renal function in chloralkali workers previously exposed to mercury vapor and to assess the impact of selenium status on the biomarkers of kidney function.


METHODS
Forty-nine chloralkali workers previously exposed to mercury vapor were compared with 49 age-matched referents in a cross-sectional study. Selected biomarkers of kidney function and biomarkers of selenium status were measured. The index group had been exposed for 13.1 (range 2.8-34.5) years on the average at a mean urinary mercury excretion of 9.3 (range 4.0-25.4) nmol/mmol creatinine a year. The exposure had ceased on an average of 4.8 (range 4.2-10.0) years prior to the examinations.


RESULTS
No statistically significant differences were found between the groups for the measured biomarkers of kidney function. The serum selenium concentration and serum glutathione peroxidase activity were associated with the activity of N-acetyl-beta-D-glucosaminidase in urine (U-NAG). The results indicate that having higher glutathione peroxidase activity or a higher serum selenium concentration results in a lower excretion of U-NAG. This effect was the most pronounced in the oldest third of the participants. Apparently the well-known association between U-NAG and age could only be found for the participants with a lower selenium status.


CONCLUSIONS
Increased activities of U-NAG during ongoing exposure to mercury vapor appear to be reversible upon cessation of exposure. Selenium status has a substantial impact on U-NAG activity and should be considered in studies of U-NAG excretion.
Efskind
Jon
J
Health Department, Borregaard Ind. Ltd, PO Box 162, N-1721 Sarpsborg, Norway. Jon.Efskind@Borregaard.com
Ellingsen
Dag G
DG
Hartman
Anders
A
Thomassen
Yngvar
Y
Ulvik
Rune J
RJ
Gaarder
Per I
PI
Solberg
Tone Bente
TB
D000118:Acetylglucosaminidase / Q000652:urine; D000328:Adult; D000368:Aged; D000468:Alkalies / Q000633:toxicity*; D015415:Biomarkers / Q000652:urine; D003404:Creatinine / Q000652:urine; D003430:Cross-Sectional Studies; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008628:Mercury / Q000633:toxicity*; D008875:Middle Aged; D014131:Trace Elements / Q000652:urine
D000468:Alkalies; D015415:Biomarkers; D014131:Trace Elements; D003404:Creatinine; D005979:Glutathione Peroxidase; D000118:Acetylglucosaminidase; D008628:Mercury