Study type: Medical/biological study (experimental study)

Brain tumour development in rats exposed to electromagnetic fields used in wireless cellular communication med./bio.

Published in: Wireless Networks 1997; 3 (6): 463-469

Aim of study (acc. to author)

To investigate brain tumor development in rats exposed to 915 MHz electromagnetic fields (EMF) by continuous waves (CW) and different pulse-modulated waves. A rat in vivo glioma-model, using RG2 and N32 cells, were used for tumor induction.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 915 MHz
Modulation type: CW
Exposure duration: repeated daily exposure, 7 h/day, 5 days/week, for 10-15 days
Exposure 2: 915 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 7 h/day, 5 days/week, for 10 days
Exposure 3: 915 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 7 h/day, 5 days/week, for 10 days
Exposure 4: 915 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 7 h/day, 5 days/week, for 13 days
Exposure 5: 915 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 7 h/day, 5 days/week, for 9 days
Exposure 6: 915 MHz
Modulation type: pulsed
Exposure duration: repeated daily exposure, 7 h/day, 5 days/week, for 9-13 days

Exposure 1

Main characteristics
Frequency 915 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 7 h/day, 5 days/week, for 10-15 days
Modulation
Modulation type CW
Exposure setup
Exposure source
Chamber The test system consisted of four TEM cells. The TEM cell was enclosed in a well ventilated wooden box supporting the outer conductor made of brass-net and the central plate, or septum, constructed of aluminium and held up by Teflon braces.
Setup The animals were kept unanaesthetized and were given a half hour break for feeding after 4 hours of exposure.
Sham exposure A sham exposure was conducted.
Additional info Control animals were kept in identical TEM cells without EMF exposure.
Parameters
Measurand Value Type Method Mass Remarks
power 1 W peak value measured - -
SAR 1.67 W/kg mean measured and calculated - -

Exposure 2

Main characteristics
Frequency 915 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 7 h/day, 5 days/week, for 10 days
Modulation
Modulation type pulsed
Pulse width 0.57 ms
Rise time 0.04 ms
Fall time 0.81 ms
Duty cycle 0.2 %
Repetition frequency 4 Hz
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 2 W peak value measured - -
SAR 0.0077 W/kg mean measured and calculated - -

Exposure 3

Main characteristics
Frequency 915 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 7 h/day, 5 days/week, for 10 days
Modulation
Modulation type pulsed
Pulse width 0.57 ms
Rise time 0.04 ms
Fall time 0.81 ms
Duty cycle 0.5 %
Repetition frequency 8.33 Hz
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 2 W peak value measured - -
SAR 0.016 W/kg mean measured and calculated - -

Exposure 4

Main characteristics
Frequency 915 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 7 h/day, 5 days/week, for 13 days
Modulation
Modulation type pulsed
Pulse width 0.57 ms
Rise time 0.04 ms
Fall time 0.81 ms
Duty cycle 0.9 %
Repetition frequency 16 Hz
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 2 W peak value measured - -
SAR 0.03 W/kg mean measured and calculated - -

Exposure 5

Main characteristics
Frequency 915 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 7 h/day, 5 days/week, for 9 days
Modulation
Modulation type pulsed
Pulse width 0.57 ms
Rise time 0.04 ms
Fall time 0.81 ms
Duty cycle 12 %
Repetition frequency 217 Hz
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 2 W peak value measured - -
SAR 0.4 W/kg mean measured and calculated - -

Exposure 6

Main characteristics
Frequency 915 MHz
Type
Charakteristic
  • guided field
Exposure duration repeated daily exposure, 7 h/day, 5 days/week, for 9-13 days
Modulation
Modulation type pulsed
Pulse width 6 ms
Rise time 0.04 ms
Fall time 0.81 ms
Duty cycle 30 %
Repetition frequency 50 Hz
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 2 W peak value measured - -
SAR 1 W/kg mean measured and calculated - -

Reference articles

  • Salford LG et al. (1993): Experimental studies of brain tumour development during exposure to continuous and pulsed 915 MHz radiofrequency radiation.
  • Martens L et al. (1993): Electromagnetic field calculations used for exposure experiments on small animals in TEM-cells
  • van Hese J et al. (1992): Simulation of the effect of inhomogeneities in TEM transmission cells using the FDTD method

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

In the RG2 model there was no indication of promoted tumor growth for any of the tested EMF-frequencies. As a reason for the absence of significant differences between exposed and control animals it should be kept in mind that the rat glioma tumor cell line RG2 is very aggressive, and the addition of external stimuli may therefore not influence upon the tumor growth rate. Also the less aggressive, slow-growing N32 cell line changed the tumor volume in no significant way of the exposed animals compared to their controls. In conclusion no differences were found between the growth of inoculated rat brain tumors in EMF exposed animals and their unexposed controls.

Study character:

Study funded by

Related articles