Study type: Medical/biological study (experimental study)

Low-frequency electromagnetic radiation enhances the induction of rat mammary tumors by nitrosomethyl urea. med./bio.

Published in: Cancer Lett 1991; 61 (1): 75-79

Aim of study (acc. to author)

To investigate the effects of low frequency electromagnetic fileds on mammary carcinoma in rat induced by N-nitrosomethylurea (NMU).

Background/further details

Rats were kept under normal light conditions (i.e. 12 h light/ 12 h dark) and were exposed either to static or to variable magnetic fields (MF). Exposure conditions were chosen 0.5 and 3 h per day, respectively for a time periode of 2 years. One part of the animals recived a single intravenously injection of 50 mg/kg of the chemical carcinogen NMU. None-NMU-treated and none-exposed animals served as control.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: 0.5 or 3 h/day for 2 years
Exposure 2:
Exposure duration: 0.5 or 3 h/day for 2 years

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration 0.5 or 3 h/day for 2 years
Exposure setup
Exposure source
Chamber Solenoid boxes/ 75 x 60 x 45 cm
Setup Cages were placed in the solenoid boxes.
Parameters
Measurand Value Type Method Mass Remarks
magnetic field strength 16 A/m effective value unspecified - -

Exposure 2

Main characteristics
Frequency
Type
Exposure duration 0.5 or 3 h/day for 2 years
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic field strength 16 A/m effective value unspecified - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Without prior administration of NMU, magnetic filed exposure lead only to a week development of mammary carcinomas. Incidence and latent period of mammary tumors depend on duration and kind of the magnetic field exposure. A 3 h exposure and exposure with variable magnetic field were more effective than a 0.5 h exposure and exposure with static magnetic fields, respectively. Beside prevailed mammary adenocarcinomas neoplasms were found occassionaly in kidneys, ovary, large intestine, uterus and thyroid gland.

Study character:

Study funded by

Related articles