Study type: Medical/biological study (experimental study)

Radiofrequency electromagnetic fields have no effect on the in vivo proliferation of the 9L brain tumor. med./bio.

Published in: Radiat Res 1999; 152 (6): 665-671

Aim of study (acc. to author)

To determine if exposure to a radiofrequency electromagnetic field similar to those used in cellular phone has any effects on the growth of a central nervous system tumor. The intracranial 9L (gliosarcoma cells) tumor model was used.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 835.26 MHz
Exposure duration: repeated daily exposure, 4 h/day, 5 days/week, for up to 178 days
  • power: 1.5 W cf. remarks (± 0.25 W slot-average)
  • SAR: 0.75 W/kg cf. remarks (brain) (± 0.25 W/kg slot-average)
Exposure 2: 847.74 MHz
Exposure duration: repeated daily exposure, 4 h/day, 5 days/week, for up to 178 days
  • power: 1.5 W cf. remarks (± 0.25 W slot-average)
  • SAR: 0.75 W/kg cf. remarks (brain) (± 0.25 W/kg slot-average)

General information

Rats were assigned randomly to one of three exposure groups that were injected in the brain with three different numbers of tumour cells.

Exposure 1

Main characteristics
Frequency 835.26 MHz
Type
Exposure duration repeated daily exposure, 4 h/day, 5 days/week, for up to 178 days
Additional info FMCW
Modulation
Modulation type cf. additional info
Additional info

FMCW

Exposure setup
Exposure source
Chamber RF field exposure was carried out in the "chamberettes" described in [Moros et al., 1998]. Each chamberette consisted of four carousels stacked vertically. In order to factor out possible confounders, the angular orientation of the carousel and the location (shelf and chamber) were varied every day according to a randomization schedule.
Setup Ten animals, each housed in a cylindrical restrainer, were placed on a carousel, equidistant from the central dipole antenna with their heads pointing towards the center. Sham-exposure carousels had no antenna. Larger restraint devices were used as the animals grew, in order to maintain the appropriate distance from the source.
Sham exposure A sham exposure was conducted.
Additional info Exposure of the animals started 4 weeks before and continued up to 150 days after the implantation of tumour cells.
Parameters
Measurand Value Type Method Mass Remarks
power 1.5 W cf. remarks - - ± 0.25 W slot-average
SAR 0.75 W/kg cf. remarks measured brain ± 0.25 W/kg slot-average

Exposure 2

Main characteristics
Frequency 847.74 MHz
Type
Exposure duration repeated daily exposure, 4 h/day, 5 days/week, for up to 178 days
Additional info CDMA
Modulation
Modulation type cf. additional info
Additional info

CDMA

Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power 1.5 W cf. remarks - - ± 0.25 W slot-average
SAR 0.75 W/kg cf. remarks measured brain ± 0.25 W/kg slot-average

Reference articles

  • Moros EG et al. (1999): Compact shielded exposure system for the simultaneous long-term UHF irradiation of forty small mammals. II. Dosimetry.
  • Moros EG et al. (1998): A compact shielded exposure system for the simultaneous long-term UHF irradiation of forty small mammals: I. Electromagnetic and environmental design.

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)

Exposure under these conditions did not result in any differences in the growth of 9L glioma cells implanted in rats. The animals exposed to CDMA (code division multiple access) or FMCW (frequency modulated continuous wave) had similar survival parameters. Survival curves for the exposed groups showed no significant differences compared to sham-exposed controls.

Study character:

Study funded by

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