Study type: Medical/biological study (experimental study)

Growth variations in OF1 mice following chronic exposure of parental and filial generations to a 15 µT, 50 Hz magnetic field. med./bio.

Published in: Electromagn Biol Med 2012; 31 (1): 19-33

Aim of study (acc. to author)

To study the effects of chronic exposure to a 50 Hz magnetic field on the growth of a first filial generation (F1) of mice.

Background/further details

The parental generation (P1) was exposed for 98 days, subsequently they were mated, went through pregnancy, birth, lactation, and the weaning of their offspring under exposure in this field. The offspring was exposed until reaching adulthood (220 days).
The parental generation (21 females and 11 males) was randomly divided into four groups according to sex and treatment: two control groups (10 females and 5 males) and two exposure groups (11 females and 6 males). The first filial generation control group consisted of 79-85 animals until 21 days after birth and of 37-39 females and 38-40 males in the phase from day 21 until the end of the experiment (day 220). The first filial generation exposure group consisted of 110-125 animals until 21 days after birth and of 53-55 females and 53-55 males in the phase from day 21 until the end of the experiment.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for up to 32 weeks, see add.information

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for up to 32 weeks, see add.information
Exposure setup
Exposure source
Setup pair of circular coils with a radius of 0.375 m, placed in a horizontal plane, spaced 0.375 m apart; each coil consisting of 220 turns of copper wire with a diameter of 1.2 mm; animals placed in 37 cm x 29 cm x 19 cm Makrolon type III cages; the parental generation was exposed in groups of 5-6 animals/cage before mating; after mating two females were exposed in one cage until birth and subsequently together with their pups; 21 days old pups were separated by gender and continued with exposure in groups of max. 9 animals
Sham exposure A sham exposure was conducted.
Additional info parental generation exposed from the age of 42 days on; first filial generation exposed in uterus and 220 days postnatal
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 15 µT effective value measured - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated material:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The magnetic field exposure had no significant effects on dam body mass, litter size, or offspring birth weight.
The data suggest that a sinusoidal magnetic field of 15 µT and 50 Hz induced statistically significant effects on growth of the offspring. Magnetic field exposure was associated with a marked increase in maximum growth rate in the exposed animals during the post-weaning growth acceleration phase (phase 2).
In addition, the growth stabilization phase (phase 3) in exposed males was shorter than in the control animals. Furthermore, statistically significant differences (reductions) were found between the mean body masses of exposed males and control males (F1) from 49-123 days.
Exposure to the magnetic field might have been associated with the stimulated growth rate observed over the noticeably shortened second and third growth phases (leaving these animals lighter by the stationary phase compared to controls) and a possible acceleration of aging. Both processes could be responsible for the stationary phase being reached at an earlier age, especially in males.

Study character:

Study funded by

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