Study type: Medical/biological study (experimental study)

Studies on the possible endocrinological effects of a 50 Hz electromagnetic field. med./bio.

Published in: Cent. Eur. J. Occup. Environ. Med. 2000; 6 (2-3): 183-188

Aim of study (acc. to author)

The effects of exposure of rats to a 50 Hz magnetic field on morphological parameters of the pineal gland, thyroid gland and adrenal gland should be investigated.

Background/further details

A total of 63 male rats was used in the study. 37 rats were exposed to the magnetic field (exposure groups) for 2, 3, 4, 5 or 6 months. For each group, a separate control group was used (remark EMF-Portal: the sizes of the individual groups are not specified in the article). Additionally, an unknown number of animals (remark EMF-Portal: also rats?) was exposed or not exposed (control group) to the magnetic field over 3 months in summer (summer group) or winter (winter group).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 7 h/day, 5 days/week for 2, 3, 4, 5 and 6 months starting 24 h after birth

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 7 h/day, 5 days/week for 2, 3, 4, 5 and 6 months starting 24 h after birth
Exposure setup
Exposure source
Chamber cages
Setup coil consisting of 1320 turns of 2.5 mm thick wire wound on a wooden frame; cages with animals placed symmetrically on both sides of the coil, resulting in a magnetic field with decaying strength in the cages
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 10 V/m maximum measured - anywhere in the room
magnetic flux density 50 µT minimum - - decaying field along the cages
magnetic flux density 500 µT maximum - - decaying field along the cages

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

In the thyroid gland, exposure to the magnetic field months led to a significantly increased volume density of the follicular epithelium and significantly increased activation index after 2 months and 4 months compared to the control groups. However, these parameters were significantly decreased after 3, 5 and 6 months of exposure.
In the pineal gland, the volume density of interfollicular tissue was significantly decreased after 3 months and significantly increased after 5 and 6 months of exposure in comparison to the control groups while no changes were observed after 2 and 4 months. The volume density of pinealocytes showed a significant decrease both during summer and winter in exposed animals compared to the control groups.
In the adrenal gland of exposed animals, a significantly increased volume density of the adrenal cortex compared to the control group was found after 5 months while the volume density of the medulla was significantly decreased (remark EMF-Portal: there were no further results for the adrenal gland stated).
The authors conclude that exposure of rats to a 50 Hz magnetic field might cause morphological changes in the pineal gland, thyroid gland and adrenal gland.

Study character:

Study funded by

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