P. Bulat et al., ACTIVITY OF GLUTATHIONE-PEROXIDASE AND SUPEROXIDE-DISMUTASE IN WORKERS OCCUPATIONALLY EXPOSED TO MERCURY, International archives of occupational and environmental health, 71, 1998, pp. 37-39
According to previous research the lipid peroxidation process has a si
gnificant role in mercury toxicity. Since glutathione peroxidase (GPX)
and superoxide dismutase (SOD) play a significant role in erythrocyte
antioxidative defence, it is very important to determine their activi
ty in occupationally exposed workers. The aim of this study was to ass
ess the activity of antioxidative enzymes in the erythrocytes of worke
rs occupationally exposed to mercury. We compared a group of 42 worker
s exposed to elemental mercury in a chloralkali plant (Hg group). The
control group (C group) consisted of 75 subjects employed in lime prod
uction who had never been exposed to mercury or any toxic substance. T
he GPX activities in erythrocytes were significantly lower in the Hg g
roup than in the control group (Hg group, 9.05 +/- 7.52 IU/gHb; C grou
p 15.54 +/- 4.85 IU/gHb; p < 0,001). Also, SOD activity in the erythro
cytes of workers occupationally exposed to mercury was significantly l
ower than in the control group (Hg group, 1280.7 +/- 132.3 IU/gHb; C g
roup, 1377.9 +/- 207.5 IU/gHb; p < 0.006). The concentrations of mercu
ry in blood were significantly higher in the Hg group compared to the
control group (Hg group, 0.179 +/- 0.040 mu mol/l; C group, 0.023 +/-
0.011 mu mol/l; p < 0.001). Urine mercury concentrations were also sig
nificantly higher in the Hg group than in the control group (Hg group,
23.2 +/- 11.3 nmol/mmol creatinine; C group, 2.7 +/- 0.6 nmol/mmol cr
eatinine; p < 0.001). The concentrations of selenium in erythrocytes w
ere almost equal in both groups examined (Hg group, 62.9 +/- 8.72 mu g
/l; C group, 65.8 +/- 10.57 mu g/l) Also, in the Hg group there were i
ncreased levels of erythrocyte malondialdehyde (Hg group, 138.58 +/- 3
3.85 mu mol/l; C group 105.21 +/- 49.62 mu mol/l; p < 0.001). On the b
asis of previous results, it can be concluded that occupational exposu
re to elemental mercury leads to increased lipid peroxidation in eryth
rocytes. Also, it can be postulated that this exposure leads to decrea
sed activity of GPX and SOD in erythrocytes.