Study type: Medical/biological study (experimental study)

Mammary tumours in Sprague-Dawley rats after initiation with DMBA followed by exposure to 50 Hz electromagnetic fields in a promotional scheme. med./bio.

Published in: Cancer Lett 1998; 123 (1): 107-111

Aim of study (acc. to author)

To investigate whether a transient-producing intermittent magnetic field exerts a promoting effect on DMBA-induced mammary tumor development in rat.

Background/further details

A total of 180 animals were used in this study, divided into 3 groups: Group A) 60 rats, 0.25 mT MF exposure, DMBA-treated. Group B) 60 rats, 0.5 mT MF exposure, DMBA-treated. Group C) 60 animals, no MF exposure, DMBA-treated.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: intermittent, 15s on/off, 19 h/day (weekdays), 21 h /day (weekends), for 21 weeks
Exposure 2: 50 Hz
Exposure duration: intermittent, 15s on/off, 19 h/day (weekdays), 21 h /day (weekends), for 21 weeks

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent, 15s on/off, 19 h/day (weekdays), 21 h /day (weekends), for 21 weeks
Exposure setup
Exposure source
  • pls. see the reference article
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 250 µT unspecified measured - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent, 15s on/off, 19 h/day (weekdays), 21 h /day (weekends), for 21 weeks
Exposure setup
Exposure source
  • pls. see the reference article
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 500 µT unspecified measured - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

A single application of 7 mg DMBA/animal was given to rats 52 days of age and MF exposure were initiated 7 days thereafter and ongoing for 21 weeks.
No statistical difference was found either for tumor-bearing animals or for the total number of tumors. Animals exposed to 0.25 mT exhibited a slightly larger total tumor weight and tumor volume, but these findings were not statistically significant.

Study character:

Study funded by

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