Abstract
In workers exposed to an average atmospheric mercury vapor concentration below the current threshold limit value (TLV, 0.050 mg/cu m), the following biological changes were detected: increased blood and urine mercury concentrations, increased plasma galactosidase and plasma catalase activities, decreased red blood cell (RBC) cholinesterase activity. A significant correlation was found between airborne mercury level and urinary mercury concentration (r = 0.47), between mercury concentration in blood and in urine (r = 0.36), and between airborne mercury concentration and RBC cholinesterase inhibition (r = 0.33). Serum cholinesterase, RBC δ-aminolevulinic acid (ALA) dehydratase, and urine ALA levels were normal. No significant anomalies were found on the amino acid chromatographs and protein electrophoresis of serum and urine.