Medindia (Chennai, India)
October 11, 2005


The increasing number of telecommunication devices available and the
length of time spent using mobile telephones has aroused interest for
possible interactions between humans and radio-frequency (RF)
radiations. It has been proposed that a precautionary principle should
be adopted, particularly for children even if, at present, there is no
convincing scientific data to recommend such a limited use of mobile

In view of the proximity between radio-frequency source (i.e. mobile
phones) and the human brain, several studies have investigated the
effects of electromagnetic fields (EMFs) on resting cerebral activity,
but results have often been contradictory.

A recent study, to be published in the next issue of Neuroscience
Research, was conducted with the aim to test whether a global system
for mobile communication (GSM) signal affects human resting EEG,
analyzed with a high EEG frequency resolution, and, when this
influence is most evident on EEG spectral power, i.e. whether this is
restricted to the period of real exposure or if it continues after
exposure cessation.

Researchers from Italy recorded the resting electroencephalogram of 20
healthy subjects in order to investigate the effect of EMF exposure on
EEG waking activity and its temporal development. The subjects were
randomly assigned to two groups and exposed, in double-blind
conditions, to a typical mobile phone signal before or during the EEG
recording session.

The results show that, under real exposure as compared to baseline and
sham conditions, EEG spectral power was influenced in some bins of the
alpha band. This effect was greater when the EMF was on during the EEG
recording session than before it.

The authors conclude that EMFs like the ones emitted by mobile phones
influence normal brain physiology, probably by means of changes in
cortical excitability. However, the authors add that conclusions about
possible health consequences are premature, particularly with respect
to chronic and/or repeated exposures, and investigations on cell
mechanisms are needed to better understand the macroscopic cerebral

Copyright Medindia 2005