Study type: Medical/biological study (experimental study)

No evidence of persisting unrepaired nuclear DNA single strand breaks in distinct types of cells in the brain, kidney, and liver of adult mice after continuous eight-week 50 Hz magnetic field exposure with flux density of 0.1 mT or 1.0 mT med./bio.

By: Korr H, Angstman NB, Born TB, Bosse K, Brauns B, Demmler M, Fueller K, Kantor O, Kever BM, Rahimyar N, Salimi S, Silny J, Schmitz C
Published in: PLoS One 2014; 9 (10): e109774
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Aim of study (acc. to author)

The effects on DNA, with focus on single-strand breaks, in different types of cells in brain, kidney and liver of mice after a chronic whole body exposure to 50 Hz magnetic fields should be investigated.

Background/further details

86 mice were separated into the following three groups: 1) 26 animals as sham exposure, 2) 30 animals exposed to a magnetic field with 0.1 mT und 3) 30 animals exposed to a magnetic field with 1.0 mT. After exposure, 10 animals per group were chosen randomly (the remaining animals were not investigated in this study) and DNA damage was investigated.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 8 weeks
Exposure 2: 50 Hz
Exposure duration: continuous for 8 weeks

General information

experimental set-up differes from reference set-up due to a different amount of test animals and a different magnetic flux density used

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 8 weeks
Exposure setup
Exposure source
Chamber 30 mice were kept in metal free cages (14 cm height, 16 cm width, 22 cm depth) in groups of five per cage and exposed simultaneously for each magnetic flux density tested
Setup a pair of identical circular Helmholtz coils with a diameter of 69 cm and separated by a distance of 34.5 cm
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.1 mT - measured - -
Additional parameter details

the magnetic fields generated in the laboratory by the 50 Hz power supply were lower than 0.2 µT. In the control cages, the maximal flux density of 50 Hz magnetic fields was 0.15 µT. The earth's DC magnetic field was below 50 µT in all areas of the investigations.

Exposure 2

Main characteristics
Frequency 50 Hz
Exposure duration continuous for 8 weeks
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - measured - -

Reference articles

  • Schmitz C et al. (2004): 50-Hz magnetic field exposure influences DNA repair and mitochondrial DNA synthesis of distinct cell types in brain and kidney of adult mice

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Neither the exposure to the magnetic field with 0.1 mT nor with 1.0 mT resulted in any increase of unrepaired nuclear DNA single-strand breaks in any cell types investigated compared to sham exposure. However, the exposure with 1.0 mT led to significantly reduced unscheduled DNA synthesis in one type of brain and kidney cells, as well as to significantly reduced mitochondrial DNA synthesis in both types of brain cells.
The authors conclude that the results indicate no increase of single-strand breaks as an effect of a chronic whole body exposure of mice to 50 Hz magnetic fields up to 1.0 mT.

Study character:

Study funded by

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