Study type: Medical/biological study (experimental study)

The effects of 860 MHz radiofrequency radiation on the induction or promotion of brain tumors and other neoplasms in rats. med./bio.

Published in: Radiat Res 2001; 155 (4): 572-583

Aim of study (acc. to author)

To determine if exposure to a pulsed-wave radiofrequency or a continuous-wave radiofrequency as emitted from hand-held mobile telephones induced or promoted brain tumors or other neoplasms in rats. Ethylnitrosourea (ENU) was selected to induce brain tumors.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 860 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 6 h/day, 5 days/week, from 2 up to 24 months of age
  • SAR: 1 W/kg average over mass (brain) (± 0.2 W/kg)
  • SAR: 0.42 W/kg average over mass (whole body) (0.27-0.42 W/kg)
Exposure 2: 860 MHz
Modulation type: FM, CW
Exposure duration: repeated daily exposure, 6 h/day, 5 days/week, from 2 up to 24 months of age
  • SAR: 1 W/kg average over mass (brain) (± 0.2 W/kg)
  • SAR: 0.42 W/kg average over mass (whole body) (0.27-0.42 W/kg)

General information

Fifteen groups of 60 rats each were formed from offspring of females injected i.v. with 0, 2.5 or 10 mg/kg of ENU to induce brain tumours. They were exposed to pulsed or continuous RF or sham-exposed, and groups 13-15 were cage controls.

Exposure 1

Main characteristics
Frequency 860 MHz
Type
Exposure duration repeated daily exposure, 6 h/day, 5 days/week, from 2 up to 24 months of age
Modulation
Modulation type pulsed
Additional info

The signal had a frame rate of 11.1 Hz and a duration of 15 ms.

Exposure setup
Exposure source
Distance between exposed object and exposure source 2 cm
Chamber A series of carousels made of perforated Plexiglas were placed in Plexiglas racks.
Setup Each carousel held 10 rats facing a central dipole antenna at 2.0 ± 0.5 cm from their noses. For groups 1-6, rats were restrained in size-adjustable individual pie-shaped chambers. For groups 7-12, the carousel units were modified to be similar to those used by Adey et al. [1999] and thus easier to sanitise. These units were perforated Plexiglas cylinders fitted with detachable cone-shaped headpieces and adjustable back stops.
Sham exposure A sham exposure was conducted.
Additional info Removed rats were replaced with a phantom, i.e., a plastic tube with a cone shaped head filled with a gel having dielectric properties similar to muscle tissue.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1 W/kg average over mass measured and calculated brain ± 0.2 W/kg
SAR 0.42 W/kg average over mass measured and calculated whole body 0.27-0.42 W/kg

Exposure 2

Main characteristics
Frequency 860 MHz
Type
Waveform
Exposure duration repeated daily exposure, 6 h/day, 5 days/week, from 2 up to 24 months of age
Modulation
Modulation type FM, CW
Additional info

random modulation simulating voice transmission

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1 W/kg average over mass measured and calculated brain ± 0.2 W/kg
SAR 0.42 W/kg average over mass measured and calculated whole body 0.27-0.42 W/kg

Reference articles

  • Adey WR et al. (1999): Spontaneous and nitrosourea-induced primary tumors of the central nervous system in Fischer 344 rats chronically exposed to 836 MHz modulated microwaves.

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 was no significant evidence that the continuous-wave (CWRF) or pulsed-wave radiofrequency (PRF) induced neoplasia in any tissues or promoted CNS tumors. CWRF or PRF had no statistically significant effect on the number, volume, location, multiplicity, histological type, malignancy or fatality of brain tumors.

Study character:

Study funded by

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