Medical/biological study (experimental study)

Evaluating DNA damage in rodent brain after acute 60 Hz magnetic-field exposure med./bio.

By: McNamee JP, Bellier PV, Chauhan V, Gajda GB, Lemay E, Thansandote A

Published in: Radiat Res 2005; 164 (6): 791-797

Aim of study (acc. to author)

To investigate whether acute magnetic field exposure could elicit DNA damage within brain cells from both whole brain and cerebellar homogenates from adult rats, adult mice, and immature mice.

Background/further details

Adult rats, mice, and immature mice in the positive control group were exposed to X-rays (2 Gy).

Endpoint

genotoxicity/mutation: DNA damage

Exposure

- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 60 Hz Exposure duration: continuous for 2 h	magnetic flux density: 0.1 mT magnetic flux density: 1 mT magnetic flux density: 2 mT

Exposure 1

Main characteristics

Frequency	60 Hz
Type	magnetic field
Waveform	unspecified
Exposure duration	continuous for 2 h

Exposure setup

Exposure source	Merritt coils
Chamber	Two Quad/4x in vivo magnetic field exposure chambers. Each chamber consisting of 4 x 4 Merritt sets with 40 cm² square coils.
Additional info	Sham exposure was performed by configuring the coils in buck mode. Negative (0 Gy X-ray) and positive (2 Gy X-ray) controls were processed with each experimental exposure.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	0.1 mT	-	measured	-	-
magnetic flux density	1 mT	-	measured	-	-
magnetic flux density	2 mT	-	measured	-	-

Measurement and calculation details

Magnetic field was measured with EMDEX 2 high field meters.

Exposed system:

animal
rat/Sprague-Dawley and mouse/ICR

Methods Endpoint/measurement parameters/methodology

genotoxicity/mutation: DNA damage (alkaline Comet assay; tail ratio (relative fluorescence intensity in the comet tail region to that in the entire comet), tail moment, comet length (entire length of comet), tail length)
effects on the neurological system: DNA damage in rodent brains (see genotoxicity/mutation)

Investigated system:

Investigated organ system:

brain/CNS

Time of investigation:

after exposure

Main outcome of study (acc. to author)

For each species, a significant increase in DNA damage was detected by each of the four parameters of the comet assay in the positive control relative to the concurrent non-irradiated negative and sham controls.
However, none of the four parameters detected a significant increase in DNA damage in brain cell homogenates from any magnetic field exposure at any time after exposure. The dose-response and time-course data from the multiple animal groups tested in this study provide no evidence of magnetic field-induced DNA damage.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

not stated/no funding

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