Study type: Medical/biological study (experimental study)

Induction of DNA strand breaks by intermittent exposure to extremely-low-frequency electromagnetic fields in human diploid fibroblasts. med./bio.

Published in: Mutat Res Genet Toxicol Environ Mutagen 2002; 519 (1-2): 1-13

Aim of study (acc. to author)

To study possible genotoxic effects due to extremely low frequency electromagnetic field exposure in human fibroblasts.

Background/further details

The study is part of the REFLEX project (risk evaluation of potential environmental hazard from low energy electromagnetic field exposure using sensitive in vitro methods) funded by the European Union, involving 12 independent research groups.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 24 hours
Exposure 2: 50 Hz
Exposure duration: intermittent (patterns see below) for 24 hours
Exposure 3: 50 Hz
Exposure duration: intermittent (5 min on/10 min off) for 24 hours

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 24 hours
Exposure setup
Exposure source
Chamber Both systems were placed inside a commercial incubator to ensure constant environmental conditions (37 °C, 5% CO2, 95% humidity).
Setup two four-coil systems (two coils with 56 windings, two coils with 50 windings), each placed inside a µ-metal box
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1,000 µT - measured - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent (patterns see below) for 24 hours
Exposure setup
Exposure source
Additional info exposure time patterns 15 min on/15 min off 5 min on/5, 10, 15, 20, 25 min off 1, 3, 10, 15, 25 min on/10 min off
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1,000 µT - measured - -

Exposure 3

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent (5 min on/10 min off) for 24 hours
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 20 µT minimum measured - -
magnetic flux density 2,000 µT maximum measured - 20, 50, 70, 100, 250, 500, 750, 1000, 2500 µT

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

In contrast to continuous extremely low frequency electromagnetic field exposure, the application of intermittent fields reproducibly resulted in a significant increase of DNA strand break levels, mainly double-strand breaks in comparison to non-exposed controls. The conditions of intermittence showed an impact on the induction of DNA strand breaks, producing the highest levels at "5 min field-on/10 min field-off". Individual differences in response to the electromagnetic field as well as an evident exposure-response relationship between magnetic flux density and DNA migration were also found.
The findings strongly indicate a genotoxic potential of intermittent electromagnetic field. This points to the need of further studies in vivo and consideration about environmental threshold values for extremely low frequency electromagnetic field exposure.

Study character:

Study funded by

Replication studies

Related articles