Study type: Medical/biological study (experimental study)

Lack of promotion effects of 50 Hz magnetic fields on 7,12-dimethylbenz(a)anthracene-induced malignant lymphoma/lymphatic leukemia in mice. med./bio.

Published in: Bioelectromagnetics 2008; 29 (1): 29-38

Aim of study (acc. to author)

To study whether exposure to 50 Hz circularly polarized magnetic fields of up to 350 mT for 30 weeks is associated with the increase in the incidence of DMBA-induced malignant lymphoma/lymphatic leukemia in mice in a dose-incidence manner. Furthermore, the experiment was conducted twice to confirm the reproducibility of the data.

Background/further details

New-born mice were initiated with a single subcutaneous injection of 60 µg DMBA within 24 h after birth. After weaning, the animals were randomly divided into five groups of 100 mice each (50 females and 50 males each). One group served as a cage control. The other four groups of mice were sham-exposed or exposed to either 7, 70, or 350 µT magnetic fields.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: 22 h/day, 7 days/week for 30 weeks

General information

the mice were divided in five groups: i) cage control ii) sham exposure iii) exposure to 7 µT iv) exposure to 70 µT v) exposure to 350 µT the experiment was conducted twice

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration 22 h/day, 7 days/week for 30 weeks
Exposure setup
Exposure source
Setup two orthogonal sets of four square coils; for the horizontal MF: length of coils = 2379 mm; outer coils = 52 turns, inner coils = 22 turns; for the vertical MF: length of coils = 2530 mm; outer coils = 52 turns, inner coils = 22 turns experimental area in the center of the coils: 1.3 x 1.3 x 1.3 m; animals in plastic cages on wooden shelfs in this area
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 7 µT effective value - - -
magnetic flux density 70 µT effective value - - -
magnetic flux density 350 µT effective value - - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The cumulative proportions of mice with malignant lymphoma/lymphatic leukemia in the magnetic field-exposed groups were not significantly higher than those in the sham-exposed group of each sex in individual experiments and in males and females combined in each experiment, and in all the mice from the two experiments combined.
The results provided no evidence to support the hypothesis that power frequency magnetic fields are a significant risk factor for hematopoietic neoplasia.

Study character:

Study funded by

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