Study type: Medical/biological study (experimental study)

Evaluation of the potential promoting effect of 60 Hz magnetic fields on N-ethyl-N-nitrosourea induced neurogenic tumors in female F344 rats. med./bio.

Published in: Bioelectromagnetics 2000; 21 (2): 84-93

Aim of study (acc. to author)

The possible effects of a 60 Hz linear sinusoidal magnetic field on central nervous system/peripheral nervous system tumor promotion in rats exposed to the chemical mutagen ethylnitrosourea (ENU) should be investigated in this in vivo study.

Background/further details

Altogether 400 female rats were examined in eight groups (50 animals each): 1.) no treatment, 2.) only ENU, 3.) ENU plus sham exposure, 4.-7.) ENU plus magnetic field at four different magnetic flux densities (2, 20, 200 and 2000 µT), and 8.) positive control (TPA treated animals).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: 20 h on/day, 4 h off/day from 48 h after ENU injection until weaning of the offspring (up to 65 weeks)

General information

rats were treated in 8 groups: i) saline injection ii) 5 mg/kg ENU injection iii) 5 mg/kg ENU injection + sham EMF exposure iv) 5 mg/kg ENU injection + exposure to 2 µT v) 5 mg/kg ENU injection + exposure to 20 µT vi) 5 mg/kg ENU injection + exposure to 200 µT vii) 5 mg/kg ENU injection + exposure to 2000 µT viii) 5 mg/kg ENU injection + 10 µg/kg TPA injection

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Waveform
Polarization
Exposure duration 20 h on/day, 4 h off/day from 48 h after ENU injection until weaning of the offspring (up to 65 weeks)
Exposure setup
Exposure source
Chamber 20 identical exposure modules, each containing 8 cages (3 rats per cage), arranged in 5 rows of 4 modules
Setup rectangular solenoid
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2,000 µT maximum measured - -
magnetic flux density 200 µT - measured - -
magnetic flux density 20 µT - measured - -
magnetic flux density 2 µT minimum measured - -

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 exposure to 60 Hz linear sinusoidal magnetic fields had no effect on the survival of female rats or on the tumor incidence of the central nervous system/peripheral nervous system.
These results indicate that magnetic fields have no promoting effect on neurogenic tumors in the female rats exposed to the chemical mutagen ENU.

Study character:

Study funded by

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