Medical/biological study (experimental study)

Effect of long-term 50 Hz magnetic field exposure on the micronucleated polychromatic erythrocytes of mice med./bio.

By: Alcaraz M, Olmos E, Alcaraz-Saura M, Achel DG, Castillo J

Published in: Electromagn Biol Med 2014; 33 (1): 51-57

Aim of study (acc. to author)

To investigate the possible genotoxic effect of extremely low frequency magnetic fields in mouse bone marrow.

Background/further details

The results of the magnetic field exposure were compared to the effects of X-radiation (50 cGy).
In total, 168 mice were used. For the magnetic field exposures as well as for the X-radiation, 14 groups were examined, resepctively (n=6 per group).
In the first experiment, mice were exposed to the magnetic field for 7, 14, 21 or 28 days and killed one day after the last exposure. The control group without magnetic field exposure was kept for 28 days. Four antioxidants (dimethyl sulfoxide (DMSO), 6-n-propyt-2-thiouracil (PTU), grape procyanidins (P), citrus flavonoids extract (CE)) were administered to try to reduce the chromosomal damage. These substances were given for 28 days. Furthermore, control groups without exposure which received the substances for 28 days were examined.
In a second experiment, mice were treated with X-radiation. The same antioxidants as in the magnetic field exposure groups were administered 5 days before or 1 day after the radiation. Additional control groups without X-radiation but with the antioxidants were examined.

Endpoint

genotoxicity/mutation: number of micronuclei in polychromatic erythrocytes

Exposure

- 50/60 Hz
- magnetic field
- also other exposures without EMF
- co-exposure

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: continuous for 7, 14, 21 or 28 days	magnetic flux density: 200 µT (± 20 µT)

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Exposure duration	continuous for 7, 14, 21 or 28 days

Exposure setup

Exposure source	coil(s)
Setup	experimental device consisted of three 100-tum coils of 1 mm diameter copper wire; to feed the coils, a variable intensity source of 50 Hz was constructed, electric current was 700 mA

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	200 µT	-	measured	-	± 20 µT

Measurement and calculation details

field was measured every 12 hours

Exposed system:

animal
mouse/Swiss
whole body

Methods Endpoint/measurement parameters/methodology

genotoxicity/mutation: number of micronuclei in polychromatic erythrocytes, number of normochromatic erythrocytes and number of total erythrocytes in the bone marrow (ratio of polychromatic erythrocytes to normochromatic erythrocytes and ratio of polychromatic erythrocytes to total erythrocytes; May-Grünwald-Giemsa staining, microscopy)

Investigated system:

DNA/RNA

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The bone marrow of magnetic field exposed mice (p value < 0.01) and of X-radiated mice (p value < 0.001) showed a significantly increased number of micronucleated erythrocytes in comparison to the corresponding control group. In the magnetic field exposed groups, an administration of the antioxidants did not significantly influence the number of micronuclei. However, groups that were treated with X-radiation and antioxidants had significantly decreased numbers of micronuclei compared to X-radiation alone.
The authors conclude that the extremely low frequency magnetic field had a genotoxic effect in mouse bone marrow and that the administered antioxidants could not prevent this effect.

Study character:

medical/biological study
experimental study
full/main study
blind study

Study funded by

International Atomic Energy Agency (IAEA)
Ministerio Espanol de Ciencia y Tecnologia (Ministry of Science and Technology), Spain

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