Study type: Medical/biological study (experimental study)

Absence of synergistic effects on micronucleus formation after exposure to electromagnetic fields and asbestos fibers in vitro. med./bio.

Published in: Toxicol Lett 1999; 108 (1): 47-53

Aim of study (acc. to author)

This study was performed to investigate the micronucleus frequency in human amniotic fluid cells following exposure to horizontally applied electromagnetic field in the presence or absence of asbestos fibers to perceive possible co-carcinogenic interactions beween electromagnetic fields and asbestos fibers.

Background/further details

The experiments were repeated six times. Cells were treated with crocidolite asbestos fibers at a concentration of 1 µg/cm2. Following treatment groups were performed: 1.) magnetic field exposure for 24 hours and then co-exposure (magnetic field plus asbestos) for 48 hours, 2.) magnetic field exposure for 48 and then co-exposure for 24 hours, 3.) co-exposure for 72 hours, and 4.) asbestos exposure for 24 hours and then co-exposure for 48 hours. Additionally, exposure to magnetic field or asbestos alone for 24, 48, and 72 hours was conducted.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 24 h, 48 h or 72 h

General information

cells were treated in the following groups: i) no exposure ii) only EMF exposure iii) only exposure to crocidolite asbestos fibres iv) 24 h EMF exposure + 48 h exposure to crocidolite asbestos fibres and EMF v) 48 h EMF exposure + 24 h exposure to crocidolite asbestos fibres and EMF vi) 72 h exposure to crocidolite asbestos fibres and EMF vii) 24 h exposure to crocidolite asbestos fibres + 48 h exposure to crocidolite asbestos fibres and EMF

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 24 h, 48 h or 72 h
Additional info horizontal
Exposure setup
Exposure source
Setup pair of Helmholtz coils with a diameter of 400 mm and 154 turns of magnetic wire each, 200 mm apart; culture plates in the center of the coil system
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - measured - +/- 0.01 mT

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

No statistically significant differences in growth curves were found between electromagnetic field and unexposed cells, but after asbestos exposure the cell number decreased continuously until no more living cells were observed after six days.
Electromagnetic field exposure or asbestos exposure alone increased micronucleus induction, reaching a maximum after 48 hours exposure period. The co-exposure did not alter the micronucleus induction.
The data indicate, that exposure to horizontally applied magnetic field and treatment with asbestos fibers possess genotoxic capability, but no synergistic effects.

Study character:

Study funded by

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