Oxidative stress associated with long term occupational exposure to extremely low frequency electric and magnetic fields

BACKGROUND: Occupational exposure to extremely low frequency electromagnetic fields (ELF-EMFs) may have harmful effects on biologic systems and has raised many concerns in the last decades. OBJECTIVE: The aim of this study was to determine the effects of exposure to extremely low frequency electric and magnetic fields on lipid peroxidation and antioxidant enzyme activities. METHODS: This study was conducted on 115 power plant workers as the exposed group and 145 office workers as the non-exposed group. The levels of Malondialdehyde (MDA), superoxide dismutase (SOD), Catalase (Cat), and total antioxidant capacity (TAC) were measured in the serum of all subjects. Exposure to ELF-EMFs was measured based on spot measurements and the IEEE Std C95.3.1 standard. RESULTS: The levels of MDA, SOD, and Cat in the exposed group were significantly higher than in the non-exposed group. However, the level of TAC was not significantly different between the exposed (2.45±1.02) and non-exposed (2.21±1.07) groups. The levels of MDA and SOD were higher among workers with higher exposure to electric fields than workers with low exposure. All oxidative stress indicators increased with increased exposure to magnetic fields, except TAC. CONCLUSIONS: The antioxidant system imbalance among power plant workers may be related to long term occupational exposure to electromagnetic fields. © 2021 - IOS Press. All rights reserved

The effect of vitamin E and C on comet assay indices and apoptosis in power plant workers: A double blind randomized controlled clinical trial

Extremely low frequency electromagnetic fields have been classified as a possible human carcinogen by the International Agency for Research on Cancer and this has raised some concern about its health effects on employees extensively exposed to these fields at thermal power plants. In this study, the effect of using vitamin E and C supplements have been examined on employees working at a thermal power plant. In this randomized controlled, double-blind clinical trial, 81 employees from different parts of the thermal power plant were enrolled between July and November 2017, and divided into four groups: Group 1 received vitamin E (400 units/day), Group 2: vitamin C (1000 mg/day), Group 3: vitamin E + C and Group 4: no intervention. DNA damage was measured in peripheral blood lymphocytes using comet assay and apoptosis, using flow cytometry. Based on the results, tail intensity and tail length in the vitamin E group, and all comet assay indices in the vitamin E + C and vitamin C groups (except DNA damage index) significantly decreased after the intervention, while the comet assay indices did not change significantly in the control group. None of the flow cytometry indices including early apoptosis, late apoptosis and necrosis changed after intervention in either group. The use of antioxidant vitamins such as E and C, can increase the activity of the non-enzymatic antioxidant defense system, and protect DNA from damage caused by exposure to extremely low frequency magnetic fields. But, taking these vitamins has no effect on apoptosis. It seems that consumption of vitamin E affected all investigated comet assay indices and can be probably considered as the best intervention. © 2020 Elsevier B.V

The Effects of Antioxidant Vitamins on Proinflammatory Cytokines and Some Biochemical Parameters of Power Plant Workers: A Double-Blind Randomized Controlled Clinical Trial

Some epidemiological studies have suggested that exposure to extremely low-frequency magnetic fields (ELF-MFs) can affect the immune system. This study aimed to investigate the effects of antioxidant vitamin consumption on proinflammatory cytokines and biochemical parameters changes. In this randomized, controlled double-blinded trial study, power plant workers exposed to ELF-MFs were enrolled based on inclusion criteria. Ninety-one eligible subjects were randomly divided into four groups: the first group (400 units of vitamin E/day), second group (1,000 mg of vitamin C/day), third group (400 units of vitamin E and 1,000 mg of vitamin C/day), and control group. The intervention was conducted for 3 months. Proinflammatory cytokines interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α), and biochemical parameters (fasting blood sugar, total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol HDL-c, total protein, and albumin) were measured among the participants� serums, before and after the intervention. The mean level of IL-6 in all vitamin-receiving groups, the mean level of IL-1β in vitamin C and E&C groups, and the mean level of TNF-α in the vitamin C group, decreased significantly after intervention. The arithmetic means of the effect sizes for IL-1β, IL-6, and TNF-α were 0.71, 0.57, and 0.2, respectively. The level of HDL-c in the vitamin E and vitamin E&C groups and the level of triglyceride in the vitamin C group significantly increased after the intervention. Taking antioxidant vitamins can prevent an increase of proinflammatory cytokines induced by prolonged exposure to ELF-MFs. Bioelectromagnetics. 2021;42:18�26. © 2020 Bioelectromagnetics Society. © 2020 Bioelectromagnetics Societ