Study type: Medical/biological study (experimental study)

Lack of a co-promotion effect of 60 Hz circularly polarized magnetic fields on spontaneous development of lymphoma in AKR mice. med./bio.

Published in: Bioelectromagnetics 2010; 31 (2): 130-139

Aim of study (acc. to author)

To study the possible effect of 60 Hz circularly polarized magnetic fields as tumor promoters of genetically initiated lymphoma in AKR mice.

Background/further details

AKR mice are genetically predisposed to spontaneously develop lymphoma and express in all tissues the retrovirus AKV, which is associated with spontaneous leukemia development in mice. 160 female animals were divided into four groups: 1) sham exposure, 2) 5 µT exposure, 3) 83.3 µT exposure, or 4) 500 µT exposure for 21 h/day from the age of 4-6 weeks to the age of 44-46 weeks.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 21 hr/day for 40 weeks

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Polarization
  • circular
Exposure duration continuous for 21 hr/day for 40 weeks
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 5 µT effective value measured - group 2 - expected maximum exposure level under 765 kV power transmission lines
magnetic flux density 83.3 µT effective value measured - group 3 - guideline level by the International Commission on Non-Ionizing Radiation Protection at 60 Hz power frequency
magnetic flux density 500 µT effective value measured - group 4 -2500 times higher than what are humans normally exposed to in the residential environment

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)

There were no exposure-related changes in mean survival time, clinical signs, body weights, hematological values, micronucleus assay, gene expression arrays, analysis of apoptosis, and necropsy findings. The histopathological examination showed lymphoma in all the groups: There were no differences in the tumor incidence between the sham exposure group and the magnetic field exposure groups (groups 2-4).
The authors conclude, taht there was no evidence that exposure to 60 Hz circularly polarized magnetic field strengths up to 500 µT promoted lymphoma in AKR mice.

Study character:

Study funded by

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