Study type: Medical/biological study (experimental study)

Thermal effects of mobile phone RF fields on children: A provocation study. med./bio.

Published in: Prog Biophys Mol Biol 2011; 107 (3): 399-403

Aim of study (acc. to author)

To examine thermal and local blood flow responses in the head of pre-adolescent during exposure to a GSM mobile phone.

Background/further details

26 boys, aged 14-15 years, took part in this study. After 5 minutes baseline the boys were 15 minutes either sham exposed or exposed, in each case followed by a 5 minutes wash out period (no exposure). Then, the boys, previously exposed, were sham exposed for 15 minutes, whereas the boys, previously sham exposed, were exposed for 15 minutes. The session ended with a 5 minutes recovery period (no exposure).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 902.4 MHz
Modulation type: pulsed
Exposure duration: continuous for 15 min
  • SAR: 0.99 W/kg average over mass (1 g) (brain)
  • SAR: 0.66 W/kg average over mass (10 g) (brain)
  • SAR: 4.3 W/kg average over mass (1 g) (head)
  • SAR: 2 W/kg average over mass (10 g) (head)

Exposure 1

Main characteristics
Frequency 902.4 MHz
Type
Exposure duration continuous for 15 min
Modulation
Modulation type pulsed
Pulse width 0.577 ms
Additional info

pulse repetition time: 4.615 ms

Exposure setup
Exposure source
Distance between exposed object and exposure source 4 mm
Setup two GSM phones placed near each ear; only the right phone transmitting; transmitter of the phone deactivated, battery removed and antenna input replaced by an external coaxial cable; exposure executed in a temperature controlled climate chamber
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.99 W/kg average over mass calculated 1 g brain
SAR 0.66 W/kg average over mass calculated 10 g brain
SAR 4.3 W/kg average over mass calculated 1 g head
SAR 2 W/kg average over mass calculated 10 g head

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The authors did not find a temperature change in the ear canal due to exposure to a GSM mobile phone. The superficial temperatures of the head decreased during the experiment in both groups, exposed and sham exposed. The cerebral blood flow did not differ between the sham exposure and the exposure periods. No changes in the oxyhemoglobin and deoxyhemoglobin contents were observed during the sham exposure and exposure periods. The blood pressure decreased during the whole test session in sham exposed and exposed groups.
The authors conclude that a short term exposure to a GSM mobile phone does not cause any significant increase in local ear temperatures or superficial cerebral blood flow among pre-adolescent boys.

Study character:

Study funded by

Related articles