Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 48 7 2019 07 01 1284 1291 Zlatko ZIMET National Institute of Public Health, Ljubljana, Slovenia Marjan BILBAN Department of Public Health, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia Joško OSREDKAR Institute of Clinical Chemistry and Biochemistry, University Medical Center Ljubljana, Ljubljana, Slovenia Borut POLJŠAK Laboratory of Oxidative Stress Research, Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia Teja FABJAN Institute of Clinical Chemistry and Biochemistry, University Medical Center Ljubljana, Ljubljana, Slovenia Kristina SUHADOLC Institute of Clinical Chemistry and Biochemistry, University Medical Center Ljubljana, Ljubljana, Slovenia 2019 06 27 Background: We aimed to investigate the polluted working environment triggers oxidative stress and alter enzymatic antioxidant activity by a short-term interval. Methods: The experimental study, performed in 2014, involved 94 workers from the Velenje Coalmine in Slovenia, arranged into three groups according to a number of consecutive working days in a mineshaft, supported by a control group. Levels of the antioxidant enzymes (GPx, CAT, SOD) together with TAC (the combined effect of all antioxidants) and 8-isoprostane (a biological marker of oxidative stress/damage) were measured in human plasma. Results: Workers occupationally exposed for three consecutive working days had significantly increased 8-isoprostane biomarker, a parameter of oxidative stress (P<0.001). The antioxidant levels of TAC (P<0.001), CAT (P<0.001) and SOD (P<0.001) were all significantly decreased compared to a control group. Conclusion: Workers in polluted working environment had significantly increased oxidative stress and altered antioxidant activity already on a third consecutive working day.   https://ijph.tums.ac.ir/index.php/ijph/article/view/17588 https://ijph.tums.ac.ir/index.php/ijph/article/download/17588/6445