Study type: Medical/biological study (experimental study)

Time-course of electromagnetic field effects on human performance and tympanic temperature. med./bio.

Published in: Neuroreport 2004; 15 (1): 161-164

Aim of study (acc. to author)

To test the existence of a time-course of the effects of electromagnetic fields on psycho-motor (reaction times) and cognitive performance (visual search and arithmetic subtraction), and on the tympanic temperature of human subjects.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 902.4 MHz
Modulation type: pulsed
Exposure duration: continuous for 45 min

General information

Every subject was submitted to three sessions in counterbalanced order: a baseline, a real, and a sham exposure session with at least 48 h between tests, following a double-blind paradigm.

Exposure 1

Main characteristics
Frequency 902.4 MHz
Type
Exposure duration continuous for 45 min
Additional info International Electrotechnical Commission. Procedure to measure the Specific Absorption Rate (SAR) for hand-held mobile wireless devices in the frequency range of 300 MHz to 3 GHz. IEC 106/49/Committee Draft, 2002.
Modulation
Modulation type pulsed
Additional info

typical GSM RF-ON signal

Exposure setup
Exposure source
Distance between exposed object and exposure source 1.5 cm
Setup The mobile phone was held by means of a helmet in the classical use position at a distance of 1.5 cm from the left ear. A second but inactive phone was positioned on the right side of the head in order to balance the weight. During the baseline session, subjects wore only the helmet without the mobile phones.
Sham exposure A sham exposure was conducted.
Additional info Every session consisted of a 45 min prerecording period, followed by 45 min of data recording. Subjects were randomly assigned to two groups being exposed before the testing session or during the data collecting session itself.
Parameters
Measurand Value Type Method Mass Remarks
power 2 W peak value - - -
power 0.25 W mean - - -
SAR 0.5 W/kg maximum measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Data indicated an improvement of both simple- and choice-reaction times and an increase of local temperature on the exposed region under the active exposure. There was a clear time-course of the reaction time and temperature data, indicating that performance and physiological measures need a minimum of 25 min of electromagnetic field irradiation to show appreciable changes.

Study character:

Study funded by

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