Study type: Medical/biological study (experimental study)

Elevated sister chromatid exchange frequencies in dividing human peripheral blood lymphocytes exposed to 50 Hz magnetic fields. med./bio.

Published in: Bioelectromagnetics 2007; 28 (4): 281-288

Aim of study (acc. to author)

To study the clastogenic potentiality of extremely low frequency electromagnetic fields on human peripheral blood lymphocytes.

Background/further details

Sister chromatid exchange frequencies were scored in dividing peripheral blood lymphocytes from six healthy male donors in two sets of experiments to determine reproducibility.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 72 h
Exposure 2: 50 Hz
Exposure duration: intermittent, 4 s on/4 s off, for 72 h
Exposure 3: 50 Hz
Exposure duration: continuous for 72 h
Exposure 4: 50 Hz
Exposure duration: intermittent, 4 s on/4 s off, for 72 h

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 72 h
Exposure setup
Exposure source
Chamber The Helmholtz coils were housed in a purpose-built incubator situated in an electrically shielded room away from any MF sources and maintained at 37 °C by a flow of warm air from a distant source (2 m).
Setup Culture tubes containing 5 ml of medium were placed within the pair of Helmholtz coils. Each coil was 180 mm in diameter and made of 100 turns of enamelled 0.7 mm diameter copper wire.
Sham exposure A sham exposure was conducted.
Additional info Control tubes were similarly cultured over a separate 72 h incubation period, but received no exposure to MFs. An independent person set the MF parameters that were unknown to the researcher.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 µT - calculated - -
magnetic flux density 1 mT - calculated - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent, 4 s on/4 s off, for 72 h
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 µT - calculated - -
magnetic flux density 1 mT - calculated - -

Exposure 3

Main characteristics
Frequency 50 Hz
Type
Waveform
  • rectangular
Exposure duration continuous for 72 h
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 µT - calculated - -
magnetic flux density 1 mT - calculated - -

Exposure 4

Main characteristics
Frequency 50 Hz
Type
Waveform
  • rectangular
Exposure duration intermittent, 4 s on/4 s off, for 72 h
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 µT - calculated - -
magnetic flux density 1 mT - calculated - -

Reference articles

  • Rapley BI et al. (1998): Influence of extremely low frequency magnetic fields on chromosomes and the mitotic cycle in Vicia faba L., the broad bean.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

A significant increase in the number of sister chromatid exchanges/cell in the exposure groups compared to the controls was found in both sets. The data showed that a square continuous waveform produced the highest number of sister chromatid exchanges in the lymphocytes.
DNA crosslinking at the replication fork is proposed as a model which could explain the mechanistic link between extremely low frequency electromagnetic field exposure and increased sister chromatid exchange frequency.

Study character:

Study funded by

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