Study type: Medical/biological study (experimental study)

The effects of pulsed 860 MHz radiofrequency radiation on the promotion of neurogenic tumors in rats. med./bio.

Published in: Radiat Res 2006; 165 (5): 608-615

Aim of study (acc. to author)

To study any promoting effect of a pulsed radiofrequency signal on latency and other characteristics of neurogenic tumors in the offspring of pregnant rats treated with ethylnitrosourea (6.25 or 10 mg/kg) by methodical comparison of tumor characteristics in serially killed exposed rats compared to sham-exposed and cage control rats.

Background/further details

In a previous study a statistically non-significant trend for shortened latency of ethylnitrosourea-induced brain tumors in rats exposed to an 860 MHz pulsed radiofrequency signal was found (see publication 6198).
Rats from each group were killed every 30 days between the ages of 171 and 325 days.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 860 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 6 h/day, 5 days/week, from 52 ± 2 days of age until scheduled killing at 30-day intervals between 171 and 325 days 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 1

Main characteristics
Frequency 860 MHz
Type
Exposure duration repeated daily exposure, 6 h/day, 5 days/week, from 52 ± 2 days of age until scheduled killing at 30-day intervals between 171 and 325 days of age
Modulation
Modulation type pulsed
Additional info

Motorola Integrated Radio Services (MiRS) signal with an 11.1-Hz frame rate and a 15-ms slot duration

Exposure setup
Exposure source
Distance between exposed object and exposure source 2 cm
Exposure room The exposure system has been described and illustrated in a previous publication [Zook and Simmens, 2001]. To reduce distortion, the exposure devices were composed entirely of Plexiglas and were located on plastic racks so that no metal or cinderblock walls were within 39 cm of the antenna.
Setup Rats were placed in well ventilated Plexiglas tubes positioned radially in a carousel exposure system with the central dipole antenna at 2.0 ± 0.5 cm directly in front of each rat's nose (5.0 ± 0.7 cm from the middle of the rat's brain). Removed animals were replaced by cone-shaped plastic tubes filled with a substance having dielectric properties similar to flesh.
Sham exposure A sham exposure was conducted.
Additional info Food and water were withheld from cage control rats when the RF and sham exposed rats were in their exposure units.
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

  • Zook BC et al. (2001): The effects of 860 MHz radiofrequency radiation on the induction or promotion of brain tumors and other neoplasms in rats.

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)

Examinations on the 1080 rats revealed 38 spinal cord tumors, 191 spinal nerve tumors, 232 cranial nerve tumors, and 823 brain tumors. The study of the tumor characteristics disclosed no evidence that exposure to the pulsed radiofrequency signal affected the incidence, malignancy, multiplicity, volume, latency or fatality associated with any kind of neurogenic tumor.

Study character:

Study funded by

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