Study type: Medical/biological study (experimental study)

Effect of a 915-MHz simulated mobile phone signal on cognitive function in man. med./bio.

Published in: Int J Radiat Biol 1999; 75 (4): 447-456

Aim of study (acc. to author)

To study whether a simulated mobile phone transmission at 915 MHz has an effect on cognitive function in human.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 915 MHz
Modulation type: CW
Exposure duration: continuous for 25 to 30 min
analog simulation
Exposure 2: 915 MHz
Modulation type: pulsed
Exposure duration: continuous for 25 to 30 min
digital simulation

Exposure 1

Main characteristics
Frequency 915 MHz
Type
Waveform
Exposure duration continuous for 25 to 30 min
Additional info analog simulation
Modulation
Modulation type CW
Exposure setup
Exposure source
  • monopole
  • quarter-wave antenna with ground plane
Setup A simulated mobile phone made of two Perspex plates and with a metal sheet sandwiched between the plates to act as a ground plane was driven by an external source connected through coaxial cable. The antenna was an 8.7 cm long steel wire in the form of sleeved monopole, at the base of which was an 0.25 λ open circuit coaxial stub formed from braid. The phone was clamped to the left ear by means of a modified ear defender and orientated in a normal position for use with the antenna adjacent to the left squamous temple bone region.
Additional info After two practice sessions, three test sessions followed with 48 hours between tests. All the meters were masked and the type of power applied to the antenna controlled by a coded three-way switch to select between no field, an analogue (exüposure 1) or a digital mode (exposure 2).
Parameters
Measurand Value Type Method Mass Remarks
power 1 W mean measured - -

Exposure 2

Main characteristics
Frequency 915 MHz
Type
Waveform
Exposure duration continuous for 25 to 30 min
Additional info digital simulation
Modulation
Modulation type pulsed
Duty cycle 12.5 %
Repetition frequency 217 Hz
Pulse type rectangular
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power 0.125 W mean measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

In both groups, the only test affected was the choice reaction time and this showed as an increase in speed, i.e. a decrease in reaction time. There was no systematic error introduced as a result of consumption of substances or sleep time.
The authors concluded that the increase in responsiveness, strongly in the analogue and less in the digital simulation, in choice reaction time could be associated with an effect on the angular gyrus that acts as an interface between the visual and speech centres. It lies directly under and on the same side as the antenna. Such an effect could be consistent with mild localized heating, or a non-thermal response.

Study character:

Study funded by

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