Medical/biological study (experimental study)

Cytogenetic effects of extremely low frequency magnetic field on Wistar rat bone marrow med./bio.

By: Erdal N, Gürgül S, Celik A

Published in: Mutat Res Genet Toxicol Environ Mutagen 2007; 630 (1-2): 69-77

Aim of study (acc. to author)

The potential genotoxic and cytotoxic effects of acute (for four hours) and long-term exposure (for 45 days) to 50 Hz magnetic field on tibia bone marrow cells of rats in vivo should be investigated.

Background/further details

The experiment was carried out with healthy adult female Wistar rats (eight weeks of age, with average body weight of 178±15 g).
The positive control consisted of animals treated with mitomycin C (2 mg/kg body weight).

Endpoint

genotoxicity/mutation: DNA damage in bone marrow

Exposure

- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: experiment 1: 4 h continuous; experiment 2: 4 h/day for 45 days	magnetic flux density: 1 mT (+/- 0.05 mT)

General information

rats were treated in four groups: i) short time exposure to EMF ii) long time exposure to EMF iii) sham exposure iv) positive control: injection of 2 mg/kg Mitomycin C

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	experiment 1: 4 h continuous; experiment 2: 4 h/day for 45 days

Exposure setup

Exposure source	Helmholtz coils
Setup	Helmholtz coil system consisting of coils with 42.75 cm diameter and a clearance of 21.375 cm, made of 160 turns of insulated copper wire; 26 x 17 x 13 cm polycarbonate cages in the center of the coils
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	1 mT	-	measured	-	+/- 0.05 mT

Exposed system:

animal
rat/Wistar
whole body

Methods Endpoint/measurement parameters/methodology

genotoxicity/mutation: DNA damage (chromosome aberrations: Giemsa stain/number of micronuclei: May-Grünwald and Giemsa stain, light microscopy)
cell viability/cell division/proliferation: cytotoxicity (mitotic index, ratio of polychromatic erythrocytes to normochromatic erythrocytes)

Investigated system:

DNA/RNA
tibia bone marrow

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The results concerning genotoxicity revealed no statistically significant differences between the negative control and the exposure groups in chromosome aberrations. However, a statistically significant higher mean micronucleus frequency was observed in the long-term magnetic field exposed group compared to the negative control and acutely magnetic field exposed group.
The mitotic index in bone marrow of both magnetic field exposed groups was significantly decreased when compared to that in the negative control. Additionally, bone marrow cytotoxicity (depression) was indicated by a significant lower ratio of polychromatic erythrocytes to normochromatic erythrocytes in both magnetic field exposed groups.
These results indicate that the exposure to extremely low frequency magnetic field may be genotoxic and cytotoxic on bone marrow cells of mammals.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

not stated/no funding

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