Study type: Medical/biological study (experimental study)

The effect of long-term extremely low-frequency magnetic field on geometric and biomechanical properties of rats' bone. med./bio.

Published in: Electromagn Biol Med 2010; 29 (1-2): 9-18

Aim of study (acc. to author)

To study the possible effects of extremely low frequency magnetic field on geometric and biomechanical properties of rats' bone.

Background/further details

30 male rats were divided into three groups: sham exposure group (n=10) and two exposure groups (n=20)

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 2 h/day for 10 months

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 2 h/day for 10 months
Exposure setup
Exposure source
Setup pair of Helmholtz coils with a diameter of 25 cm and 225 turns of insulated soft copper wire with a diameter of 1 mm; placed horizontally in a 130 cm x 65 cm x 80 cm Faraday cage; coils facing each other with a distance of 25 cm between them
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT - measured - -
cf. remarks - - measured - I = 0.12 A for B = 100 µT
magnetic flux density 500 µT - measured - -
cf. remarks - - measured - I = 0.5 A for B = 500 µT

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The data showed a significant decrease of cross-sectional area of the femoral shaft in rats exposed to a 100 µT magnetic field in comparison to sham exposed and 500 µT exposed rats. Maximum load (i.e. strength) increased in 100 µT and 500 µT exposed rats when compared to that of the sham exposed rats. The cortical thickness of the femurs of exposed rats (100 µT and 500 µT) was significantly decreased in comparison to that of the sham exposure group.
However, no significant differences were found in the other biomechanical parameters between the groups, such as e.g. length of the femur, energy absorption capacity, toughness of bone.
These experiments demonstrated that 100 µT and 500 µT magnetic fields could affect biomechanical and geometrical properties of rats' bone.

Study character:

Study funded by

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