Study type: Medical/biological study (experimental study)

Influence on the mechanisms of generation of distortion product otoacoustic emissions of mobile phone exposure med./bio.

By: Parazzini M, Bell S, Thuroczy G, Molnar F, Tognola G, Lutman ME, Ravazzani P
Published in: Hear Res 2005; 208 (1-2): 68-78
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Aim of study (acc. to author)

To study the effects of mobile phone exposure on distortion product otoacoustic emissions generation mechanisms.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 10 min
Exposure 2: 1,800 MHz
Modulation type: pulsed
Exposure duration: continuous for 10 min

General information

There were two sessions on separate days (at least 24 h apart) with a genuine (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 the other half received GSM exposure at 1800 MHz.

Exposure 1

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

The indicated maximum SAR was measured at a distance of 30 mm from the surface of the phantom. In normal phone use, this position corresponds approximately to that of the cochlea.

Measurement and calculation details

In order to estimate the level of EMF exposure in the inner ear region, SAR measurements were made in standard brain tissue equivalent liquid in a phantom using a 3-D step motor robot system, internal E-field probe and a non-metallic phone-positioning system with the phone being held on the phantom in the ''touch position'', according to CENELEC standard EN 50361. The output of the phone had previously been measured using a frequency and power meter and circulators through the external antenna output of the phone.

Exposure 2

Main characteristics
Frequency 1,800 MHz
Type
Exposure duration continuous for 10 min
Modulation
Modulation type pulsed
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power 1 W - - - -
SAR 0.19 W/kg maximum measured - -
Additional parameter details

same as E1

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)

The data showed that 10 min of electromagnetic field exposure at the maximum power (2 W at 900 MHz or 1 W at 1800 MHz) does not induce any changes in either distortion product otoacoustic emissions generation mechanism.

Study character:

Study funded by

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