Activity of antioxidative enzymes in erythrocytes and concentration of selenium in plasma related to mercury exposure.

The activity of catalase and glutathione peroxidase (GSH-Px) in erythrocytes and concentration of selenium in plasma and mercury in whole blood, plasma, and urine were analyzed in 36 individuals occupationally exposed to mercury vapor, in 14 individuals with skin hypersensitivity to inorganic mercury, and in 17 individuals with subjective symptoms alleged to result from dental amalgam fillings. The control group consisted of 39 individuals with amalgam fillings, but no occupational exposure to mercury. Selenium in plasma was determined by GFAAS with Zeeman background correction. After exclusion of individuals with reported intake of selenium supplement the median plasma selenium concentration in the group with occupational exposure to mercury was 1.24 mumol/L, in the allergy group 1.22 mumol/L, in the amalgam group 1.25 mumol/L, and in the control group 1.22 mumol/L. The activities of catalase and GSH-Px were similar in all groups. However, in females lower GSH-Px activity was found in the amalgam group compared with females in the control group. GSH-Px activity in smokers was slightly lower than in non-smokers. No correlations were found between concentration of selenium or mercury in plasma and activity of glutathione peroxidase or catalase in erythrocytes.