Potential oxidative stress in the bodies of electric arc welding operators: effect of photochemical smog.
OBJECTIVE
To investigate whether photochemical smog emitted during the process of electric arc welding might cause oxidative stress and potential oxidative damage in the bodies of welding operators.


METHODS
Seventy electric arc welding operators (WOs) and 70 healthy volunteers (HVs) were enrolled in a randomized controlled study design, in which the levels of vitamin C (VC) and vitamin E (VE) in plasma as well as the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and the level of lipoperoxide (LPO) in erythrocytes were determined by spectrophotometry.


RESULTS
Compared with the average values of the above experimental parameters in the HVs group, the average values of VC and VE in plasma as well as those of SOD, CAT and GPX in erythrocytes in the WOs group were significantly decreased (P < 0.005-0.0001), while the average value of LPO in erythrocytes in the WOs group was significantly increased (P < 0.0001). The findings from the partial correlation analysis on the controlling of age suggested that with a prolonged duration of exposure to photochemical smog the values of VC, VE, SOD, and GPX, except for CAT, in the WOs were decreased gradually (P < 0.05-0.005), the value of LPO in the WOs was increased gradually (P < 0.001), and that with the ozone dose increased in the air in each worksite VC, VE, SOD, CAT and GPX decreased (P < 0.005-0.001), but LPO increased (P < 0.001). The findings from the reliability analysis for the VC, VE, SOD, CAT, GPX, and LPO values which were used to reflect oxidative stress and potential oxidative damage in the WOs showed that the reliability coefficients' alpha (6 items) was 0.8021, P < 0.0001, and that the standardized item alpha was 0.9577, P < 0.0001.


CONCLUSIONS
Findings in the present study suggest that there exists an oxidative stress induced by long-term exposure to photochemical smog in the bodies of WOs, thereby causing potential oxidative and lipoperoxidative damages in their bodies.
Zhu
You-Gen
YG
Jinhua Municipal People's Hospital, 228 Xinhua Street, Jinhua 321000, Zhejiang, China.
Zhou
Jun-Fu
JF
Shan
Wei-Ying
WY
Zhou
Pei-Su
PS
Tong
Gui-Zhong
GZ
D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood; D002374:Catalase / Q000097:blood; D004912:Erythrocytes / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D008054:Lipid Peroxides / Q000097:blood; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood; D010083:Oxidants, Photochemical / Q000009:adverse effects* / Q000032:analysis; D018384:Oxidative Stress; D010126:Ozone / Q000032:analysis / Q000633:toxicity; D018570:Risk Assessment; D012905:Smog; D013482:Superoxide Dismutase / Q000097:blood; D014810:Vitamin E / Q000097:blood; D014896:Welding
D000975:Antioxidants; D008054:Lipid Peroxides; D010083:Oxidants, Photochemical; D012905:Smog; D014810:Vitamin E; D009569:Nitric Oxide; D010126:Ozone; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D001205:Ascorbic Acid