Study type: Medical/biological study (observational study)

Effect of extremely low frequency magnetic field on antioxidant activity in plasma and red blood cells in spot welders. med./bio.

Published in: Int Arch Occup Environ Health 2009; 82 (2): 259-266

Aim of study (acc. to author)

To determine a possible relation between exposure to extremely low frequency magnetic field and the human antioxidant activity.

Background/further details

46 male spot welders and a control group (n=45) from the same factory were examined (mean employment period = 3.8 years). Both groups were matched according to demographical characteristics, employment conditions and exclusion criteria. The workers were exposed to dynamic electromagnetic fields 40h/week (6 days/week). Prior to start of each working shift (following 12 h fasting), blood samples were obtained. Concentration of metal fume (confounder variable) was measured to control effects on antioxidant activity.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: 40 h/week for 3.8 years (mean time)

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration 40 h/week for 3.8 years (mean time)
Exposure setup
Exposure source
  • spot welding station
Distance between exposed object and exposure source 1 m
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 20 V/m minimum measured - at the worker's chest
electric field strength 133 V/m maximum measured - at the worker's chest
magnetic flux density 8.8 µT minimum measured - at the worker's chest
magnetic flux density 84 µT maximum measured - at the worker's chest

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The mean concentration of the total antioxidant activity was higher in the exposed group than in the non-exposed group; however this difference was insignificant. In the red blood cells of the exposed group, a significant decrease in superoxide dismutase activity and glutathione peroxidase activity was observed. A significant negative correlation between magnetic field intensity and superoxide dismutase activity and glutathione peroxidase activity was observed. There was no significant correlation between metal fume exposure and antioxidant acitvity.
The findings may suggest a dose-response relationship between magnetic field strength and erythrocyte antioxidant activity, which might occur even at the recommended levels of exposure.The results indicate that extremely low frequency magnetic fields could influence the red blood cell antioxidant activity and might act as an oxidative stressor.

Study character:

Study funded by

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