Renal and immunologic markers for chloralkali workers with low exposure tomercury vapor

Objectives The aim of this study was to investigate renal function and immu nologic markers among chloralkali workers with long-term low exposure to me rcury vapor. Methods Forty-seven currently exposed workers were compared with reference workers matched for age in a cross-sectional design. Results The mean urinary mercury concentration was 5.9 (range 1.1-16.8) nmo l/mmol creatinine (Cr) for the exposed workers and 1.3 (range 0.2-5.0) nmol /mmol Cr for the referents. The chloralkali workers had been exposed for an average of 13.3 (range 2.8-34.5) years. The activity of N-acetyl-beta -D-g lucosaminidase in urine (U- NAG) was higher in the exposed workers (mean 0. 18 U/mmol Cr versus 0.14 U/mmol Cr, P=0.02). Associations between current u rinary mercury, cumulative urinary mercury, and cumulative urinary mercury per year (intensity) and U-NAG, autoantibodies to myeloperoxidase (anti-MPO ) and proteinase 3 in serum, respectively, were observed. The activity of U -NAG and anti-MPG was increased in the workers with the highest exposure, a s assessed by their mean intensity of exposure. The highest activity of U-N AG was observed in the exposed workers with the lower concentrations of sel enium in whole blood. Conclusions The study indicates an effect of exposure on the kidney proxima le tubule cells, possibly modified by individual selenium status, and an ef fect mediated by neutrophil granulocytes.