Study type: Medical/biological study (experimental study)

Effects of GSM Cellular Phones on Human Hearing: The European Project "GUARD". med./bio.

Published in: Radiat Res 2007; 168 (5): 608-613

Aim of study (acc. to author)

To study the possible effects of exposure to GSM-modulated electromagnetic fields (at both 900 MHz and 1800 MHz) on the hearing system of humans.

Background/further details

169 subjects participated. The procedure was conducted twice: once with electromagnetic field exposure and once with sham exposure (at least 24 h apart).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 10 min
  • power: 2 W
  • SAR: 0.41 W/kg maximum (1 g)
Exposure 2: 1,800 MHz
Modulation type: pulsed
Exposure duration: continuous for 10 min
  • power: 1 W
  • SAR: 0.19 W/kg maximum (1 g)

General information

There were two sessions on separate days (at least 24 h apart) with a real (test) exposure and with a sham (control) exposure in a double-blind counterbalanced design. Half of the participants received GSM exposure at 900 MHz and at 1800 MHz, respectively.

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 10 min
Modulation
Modulation type pulsed
Additional info

GSM

Exposure setup
Exposure source
Setup A system of phone fixation, made of non-metallic plastic materials and consisting of a headband, an adjustable arm and a phone holder that allowed free head movement, was used for placing the phone in the normal use position, in accordance with CENELEC standard EN 50361.
Sham exposure A sham exposure was conducted.
Additional info The sham or genuine exposure was realised using a 50-Ω resistive load or an open-circuit dummy load of the same shape and structure connected to the remote antenna connector of the phone.
Parameters
Measurand Value Type Method Mass Remarks
power 2 W - - - -
SAR 0.41 W/kg maximum measured 1 g -

Exposure 2

Main characteristics
Frequency 1,800 MHz
Type
Exposure duration continuous for 10 min
Modulation
Modulation type pulsed
Additional info

GSM

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 1 W - - - -
SAR 0.19 W/kg maximum measured 1 g -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

No effects of exposure to GSM mobile phone signals on the main measures of the status of the auditory system were found.

Study character:

Study funded by

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