Study type: Medical/biological study (experimental study)

Mobile phones exposure induces changes of contingent negative variation in humans med./bio.

Published in: Neurosci Lett 2009; 464 (2): 79-83

Aim of study (acc. to author)

To study the initial contingent negative variation changes induced by 900 MHz GSM exposure in ten healthy volunteers. under three experimental conditions (randomized across the subjects and with ten minutes time interval in-between): 1) exposure to a GSM mobile phone, 2) sham exposure and 3) the phone was completely switched-off (further details see "exposure").



Exposure Parameters
Exposure 1: 900 MHz
Exposure duration: 48 trials with intervals of 4 s to 6 s
  • power: 2 W maximum
  • SAR: 0.5 W/kg maximum (+/- 0.1 W/kg phone A)

General information

subjects were tested under three conditions: i) GSM phone emitting power ii) power from the GSM phone dissipated on an internal load iii) phone switched off

Exposure 1

Main characteristics
Frequency 900 MHz
Exposure duration 48 trials with intervals of 4 s to 6 s
Exposure setup
Exposure source
Setup two commercially identical phones A and B mounted on a plastic helmet; phone B modified by connecting the output of the GSM power signal to an internal load instead of the antenna; subjects sitting in a schielded room
Sham exposure A sham exposure was conducted.
Measurand Value Type Method Mass Remarks
power 2 W maximum - - -
SAR 0.5 W/kg maximum - - +/- 0.1 W/kg phone A

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The initial contingent negative variation amplitude decreased and habituation increased during both exposure conditions (1 and 2) compared with condition 3, where the mobile phone was switched off. This effect was diffuse over the scalp, and there was no significant prevalence of amplitude decrease on the left side, where the cell phone was located. This evidence, limited by the low number of subjects investigated, could be explained in terms of an effect induced by both the GSM signal and the extremely low frequency magnetic field produced by battery and internal circuits.

Study character:

Study funded by

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