Study type: Medical/biological study (experimental study)

Absence of the effects of 50 Hz magnetic fields on the progression of acute myeloid leukaemia in rats. med./bio.

Published in: Int J Radiat Biol 2000; 76 (6): 853-862

Aim of study (acc. to author)

The effects of a whole body exposure of rats to a 50 Hz magnetic field on the progression of acute myeloid leukemia should be investigated.

Background/further details

Leukemic rats were infected with Brown Norway rat acute myeloid leukemia via cell implantation as a model for human acute myeloid leukemia because both diseases exhibit closely related characteristics.
340 rats were divided into the four following groups: 1) 103 leukemic rats exposed to the magnetic field, 2) 95 sham exposed leukemic rats, 3) 74 non-leukemic rats exposed to the magnetic field and 4) 68 non-leukemic and sham-exposed rats.
An additional, smaller population of 73 rats was used as a positive control and divided into the four following groups: 5) 23 leukemic rats exposed to 5 Gy whole body radioactive irradiation from cobalt-60, 6) 23 unirradiated leukemic rats, 7) 18 non-leukemic irradiated rats and 8) 9 unirradiated and non-leukemic rats.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 18 h/day, 7 days/week over 40 days

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 18 h/day, 7 days/week over 40 days
Exposure setup
Exposure source
Setup rectangular Helmholtz coils installed at identical intervals where the cages were settled.
Sham exposure A sham exposure was conducted.
Additional info in sham exposure cages, the magnetic field was 5 nT at night and 35 nT during the day on average.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT - measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

All rats developed leukemia after infection via transplantation and the positive control with cobalt-60 showed a significantly reduced survival rate in the radioactively exposed group 5 compared to the sham exposed group 6. This proved the method of infection reliable and showed that the model is sensitive to the effects of ionizing radiation. However, no significant differences in all investigated parameters, which would indicate an influence of the magnetic field on the progression of leukemia, could be found between groups exposed to the magnetic field and sham exposure.
The authors conclude that the used animal model is suitable to provide information on human acute myeloid leukemia and hence that the present results do not support the hypothesis that 50 Hz magnetic fields influence the progression of leukemia in humans.

Study character:

Study funded by

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