Study type: Medical/biological study (experimental study)

Repetitive exposure to a 60-Hz time-varying magnetic field induces DNA double-strand breaks and apoptosis in human cells. med./bio.

Published in: Biochem Biophys Res Commun 2010; 400 (4): 739-744

Aim of study (acc. to author)

To study the biological effects and potential genotoxicity of single or repeated exposures to a 60 Hz magnetic field on human primary fibroblasts and cancer cells.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: continuous for up to 60 min
single exposure
Exposure 2: 60 Hz
Exposure duration: continuous for 30 min/day on 3 days
repeated exposure

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Exposure duration continuous for up to 60 min
Additional info single exposure
Exposure setup
Exposure source
Setup four permanent magnets forming a plate with a diameter of 15 cm that could move up and down along a spindle so that the distance between the bottom and the magnets varied up to 12 cm; the maximum rotation speed was 1800 rpm; culture plates placed on the bottom of the exposure device which was placed inside an incubator
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 6 mT - measured - at a distance of 5 cm between magnets and cell culture plates

Exposure 2

Main characteristics
Frequency 60 Hz
Type
Exposure duration continuous for 30 min/day on 3 days
Additional info repeated exposure
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 3 mT - measured - -
magnetic flux density 6 mT - measured - at a distance of 5 cm between magnets and cell culture plates

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

While single exposure to a 60 Hz magnetic field (6 mT) did not affect cell viability in both cell types, treatment induced DNA double-strand breaks and activated DNA damage checkpoint pathway (phospho-checkpoint kinase 2 expression).
However, repetitive exposure to a 60 Hz magnetic field decreased cell viability (IMR90 cells were more sensitive than HeLa cells). Furthermore, the exposure induced persistent p38 MAPK phosphorylation and caspase-dependent apoptosis as well as DNA double-strand breaks.
In conclusion, these data suggest that daily or repetitive exposure to a 60 Hz magnetic field has genotoxic potential in human normal and cancer cells. Thus, the health risks of extremely low frequency magnetic fields of several mT should be further evaluated.

Study character:

Study funded by

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