Study type: Medical/biological study (experimental study)

Long-term Exposure to Extremely Low Frequency Electromagnetic Field and Melatonin Production by Blood Cells med./bio.

Published in: Int J Occup Environ Med 2016; 7 (3): 193-194

Aim of study (acc. to author)

The effects of exposure of rats to a 50 Hz magnetic field on the melatonin production of blood cells should be investigated.

Background/further details

It is assumed that melatonin is mainly secreted from the pineal gland and the effects of ELF-EMF on the production of melatonin from the pineal gland have been investigated during past decades. However, melatonin can also be produced by bone marrow and immune system cells in the blood.
Rats were divided into 2 groups (n=20 each): exposure group and control group.



Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: 2 hours/day for 3 months

Exposure 1

Main characteristics
Frequency 50 Hz
Exposure duration 2 hours/day for 3 months
Exposure setup
Exposure source
  • not specified
Sham exposure A sham exposure was conducted.
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Exposure of rats to the magnetic field had no significant effect on melatonin levels in serum and whole blood samples compared to the control group.
However, melatonin levels in whole blood samples of both groups were about 2.5 times higher than in serum, indicating a noteworthy melatonin production in blood cells. That might challenge the historical assumption that the pineal gland is the main source of melatonin in vertebrates.
The authors conclude that exposure of rats to a 50 Hz magnetic field has no effect on the melatonin production of blood cells.

Study character:

Study funded by

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