Study type: Medical/biological study (observational study)

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

Published in: Work 2021; 68 (2): 379-386

Aim of study (acc. to author)

The effects of long-term occupational exposure to low-frequency magnetic fields and electric fields of a power plant on lipid peroxidation and antioxidant enzyme activities in the serum of workers should be investigated.

Background/further details

Participants in this study were employees working in different sections of a power plant. A total of 115 plant workers were included in the study as the exposure group and 145 office workers were included as the control group. For statistical analysis, the exposure group was further divided into the following sub-groups: low (n=40), medium (n=37) and high (n=38) exposure to magnetic field and low (n=35), medium (n=33), and high (n=47) exposure to electric fields based on the 33rd and 66th percentiles of personal exposure measurements.

Endpoint

Exposure

Exposure Parameters
Exposure 1:
Exposure duration: at least two years work experience and a full-time job at the power plant
Exposure 2:
Exposure duration: at least two years work experience and a full-time job at the power plant
Exposure 3:
Exposure duration: at least two years work experience and a full-time job at the power plant
Exposure 4:
Exposure duration: at least two years work experience and a full-time job at the power plant
Exposure 5:
Exposure duration: at least two years work experience and a full-time job at the power plant
Exposure 6:
Exposure duration: at least two years work experience and a full-time job at the power plant

Exposure 1

Main characteristics
Frequency
Type
Exposure duration at least two years work experience and a full-time job at the power plant
Additional info low magnetic field exposure
Exposure setup
Exposure source
Setup each worker stated their working and non-working spots (e.g., their places of resting and eating lunch) during a normal work shift and the amount of time they spend at each spot; measurements were conducted at these spots at a height of 1 m above ground Ievel and for 2 min; the control group was mainly exposed to electric fields and magnetic fields generated by power lines, computers and appliances at the workplaces
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 10.42 µT maximum measured and calculated - -

Exposure 2

Main characteristics
Frequency
Type
Exposure duration at least two years work experience and a full-time job at the power plant
Additional info medium magnetic field exposure
Exposure setup
Exposure source
  • not specified
  • same setup as exposure 1
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 10.42 µT minimum measured and calculated - -
magnetic flux density 17.82 µT maximum measured and calculated - -

Exposure 3

Main characteristics
Frequency
Type
Exposure duration at least two years work experience and a full-time job at the power plant
Additional info high magnetic field exposure
Exposure setup
Exposure source
  • not specified
  • same setup as exposure 1
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 17.82 µT minimum measured and calculated - -

Exposure 4

Main characteristics
Frequency
Type
Exposure duration at least two years work experience and a full-time job at the power plant
Additional info low electric field exposure
Exposure setup
Exposure source
  • not specified
  • same setup as exposure 1
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 14.87 V/m maximum measured and calculated - -

Exposure 5

Main characteristics
Frequency
Type
Exposure duration at least two years work experience and a full-time job at the power plant
Additional info medium electric field exposure
Exposure setup
Exposure source
  • not specified
  • same setup as exposure 1
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 14.87 V/m minimum measured and calculated - -
electric field strength 25.18 V/m maximum measured and calculated - -

Exposure 6

Main characteristics
Frequency
Type
Exposure duration at least two years work experience and a full-time job at the power plant
Additional info high electric field exposure
Exposure setup
Exposure source
  • not specified
  • same setup as exposure 1
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 25.18 V/m minimum measured and calculated - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The level of malondialdehyde and enzyme activities of superoxide dismutase and catalase were significantly higher in the exposure group than in the control group. Moreover, the malondialdehyde level and superoxide dismutase enzyme activity were higher among workers with higher exposure to electric fields than workers with low exposure. The level of malondialdehyde and enzyme activities of superoxide dismutase and catalase increased with increasing exposure to magnetic fields.
The authors concluded long-term occupational exposure to low-frequency magnetic fields and electric fields of a power plant might affect lipid peroxidation and antioxidant enzyme activities in the serum of workers.

Study character:

Study funded by

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