Study type: Medical/biological study (experimental study)

Genotoxicity induced by foetal and infant exposure to magnetic fields and modulation of ionising radiation effects. med./bio.

Published in: PLoS One 2015; 10 (11): e0142259-1-e0142259-14

Aim of study (acc. to author)

The genotoxic effects of prenatal and postnatal exposure of mice to a 50 Hz-magnetic field and prior X-radiation on erythrocytes and sperms should be investigated.

Background/further details

Pregnant mice were divided into 4 groups (n=2 dams per group): 1) only exposure to the magnetic field (n=20 pups), 2) only X-radiation (1 Gy) on day 11.5 post conception (n=25 pups), 3) X-radiation and subsequent exposure to the magnetic field (n=31 pups), 4) sham exposure (n=27 pups).
On day 42 after birth, 43 young animals were sacrificed for sperm and testes examinations and the rest was killed after 140 days (remark EMF-Portal: it is not stated how many animals from each group were sacrificed and possibly more animals were killed in total. Specifications on this are contradictory and the numbers of animals used in each test are not fully comprehensible).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous form day 11.5 post conception to day 21 after birth (weaning) (30 days in total)

General information

X-irradiation was 1 Gy on day 11.5 post conception prior to MF exposure in a Gilardoni apparatus (Gilardoni, Italy) at a dose rate of 0.5 Gy/min

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous form day 11.5 post conception to day 21 after birth (weaning) (30 days in total)
Exposure setup
Exposure source
Chamber polycarbonate cages
Setup polycarbonate cages were placed in solenoid (0.8 m in length and 0.13 m in radius, with 552 turns of 2.5 mm2 copper wire, wound in two layers in continuous forward-backward fashion around a cylinder made of PVC; applied voltage was 6.5 V (rms)); the field was uniform between ± 5% in the volume where the mice were exposed; the solenoid was not shielded against the electric field, as the induced electric field was negligible due to the low voltage used; temperature and the relative humidity were 22°C and 40%, respectively
Sham exposure A sham exposure was conducted.
Additional info control and X-radiation groups were placed in a switched off solenoid
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 65 µT effective value - - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Significanly increased numbers of micronuclei in comparison to the sham exposure group (group 4) were found in groups 2 (X-radiation alone) and 3 ( X-radiation and MF exposure) at several points in time. Only after 42 days, a significantly higher amount of micronuclei compared to the sham exposure group was also observed in group 1 (magnetic field alone).
The mean testes weight was significantly smaller in all exposure groups (groups 1-3) compared to the sham exposure group. Exposure to the magnetic field alone or to X-radiation alone resulted in a significantly reduced amount of post-meiotic haploid spermatids compared to the sham exposure group and to a combination of X-radiation and MF exposure. The mean sperm numbers were significantly reduced in X-radiated mice in comparison to the sham exposure group and to a combination of X-radiation and MF exposure.
In the comet assays, the combination of X-radiation and MF exposure resulted in significantly reduced DNA damage compared to X-radiation alone.
No teratogenic effects were found in any group.
The authors conclude that prenatal and postnatal exposure of mice to a 50 Hz-magnetic field has only a slight genotoxic potential, but it might modulate the effects of prior X-radiation on sperms.

Study character:

Study funded by

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