Study type: Medical/biological study (experimental study)

The effect on rat thymocytes of the simultaneous in vivo exposure to 50-Hz electric and magnetic field and to continuous light. med./bio.

Published in: ScientificWorldJournal 2004; 4: 91-99

Aim of study (acc. to author)

The effects of exposure to extremely low frequency electric and magnetic fields on thymocytes of rats housed under different light conditions should be examined.

Background/further details

Rats were housed under a regular light/dark cycle (12 h/12 h) or under continuous light while being exposed or sham exposed for eight month. Two exposure groups were examined: 1.) electric field 1 kV/m; magnetic field 5 µT and 2.) electric field 5 kV/m; magnetic field 100 µT.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous 8 h/day, 5 days/week for 8 months
Exposure 2: 50 Hz
Exposure duration: continuous 8 h/day, 5 days/week for 8 months

General information

Rats were treated in six groups: 1) sham exposure + dark/light cycle 2) 1 kV/m exposure + dark/light cycle 3) 5 kV/m exposure + dark/light cycle 4) sham exposure + continuous light 5) 1 kV/m exposure + continuous light 6) 5 kV/m exposure + continuous light

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous 8 h/day, 5 days/week for 8 months
Exposure setup
Exposure source
Setup rats kept in individual polycarbonate cages placed in the exposure unit on electrically grounded metal nets; electric field generated by parallel electrodes with a 40 cm air gap; magnetic field generated by 5 pairs of vertically arranged coils separated by 0.6 m and mounted on wooden frames; coils 1.9 m wide and 0.95 m high
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 1 kV/m - - - -
magnetic flux density 5 µT - - - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous 8 h/day, 5 days/week for 8 months
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 5 kV/m - - - -
magnetic flux density 100 µT - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Rats housed continuously under light showed more pronounced degenerative features in the thymus when compared to rats housed under a regular dark/light cycle.
Rats that were maintained under a regular dark/light cycle and exposed to the electric and magnetic fields showed a significantly increased mitosis rate, and increased amounts of necrosis, clustered cell death (only at higher field intensity), and total cell death in comparison to the sham exposed rats, while the cell-cell adhesion was significantly decreased.
In rats, housed under continuous light and simultaneously exposed to electric and magnetic fields, the amounts of necrosis, clustered cell death (only at higher field intensity), and total cell death were significantly increased compared to sham exposed rats while the cell-cell adhesion (only at higher field intensity) was significantly decreased. Most of these changes were also significant compared to rats housed under a regular dark/light cycle and exposed to electric and magnetic fields.
The authors conclude that continuous light and exposure to electric and magnetic fields in rats can interfere with thymocytes but also have a synergistic effect.

Study character:

Study funded by

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