Rania Ghosn

Radiofrequency signal affects alpha band in resting electroencephalogram

The aim of the present work was to investigate the effects of the radiofrequency (RF) electromagnetic fields (EMFs) on human resting EEG with a control of some parameters that are known to affect alpha band, such as electrode impedance, salivary cortisol, and caffeine. Eyes-open and eyes-closed resting EEG data were recorded in 26 healthy young subjects under two conditions: sham exposure and real exposure in double-blind, counterbalanced, crossover design. Spectral power of EEG rhythms was calculated for the alpha band (8-12 Hz). Saliva samples were collected before and after the study. Salivary cortisol and caffeine were assessed by ELISA and HPLC, respectively. The electrode impedance was recorded at the beginning of each run. Compared with the sham session, the exposure session showed a statistically significant (P < 0.0001) decrease of the alpha band spectral power during closed-eyes condition. This effect persisted in the postexposure session (P < 0.0001). No significant changes were detected in electrode impedance, salivary cortisol, and caffeine in the sham session compared with the exposure one. These results suggest that GSM-EMFs of a mobile phone affect the alpha band within spectral power of resting human EEG.

Effects of GSM 900 MHz on Middle Cerebral Artery Blood Flow Assessed by Transcranial Doppler Sonography

Mobile phone use has increased worldwide but its possible effects on the brain remain unclear. The aim of the present study was to investigate the effect of acute exposure to a radio frequency electromagnetic field (RF EMF) generated by a mobile phone operating in the Global System for Mobile Communication (GSM) 900 MHz on cerebral blood flow. Twenty-nine volunteers attended two experimental sessions: a sham exposure session and a real exposure session in a cross-over double-blind study in which a mobile phone was positioned on the left side of the head. In one session, the mobile phone was operated without RF radiation (sham phone) and in the other study it was operated with RF radiation (real phone) for 20 min. Thus, each subject served as its own control. Middle cerebral artery blood flow was monitored noninvasively by transcranial Doppler sonography to measure middle cerebral artery blood flow velocity. Pulsatility index and resistance index were also evaluated. A voluntary breath holding physiological test was carried out as a positive control for testing cerebral vasoreactivity. Hemodynamic variables were recorded and analyzed before, during and after mobile phone exposure. No significant changes were detected in studied variables in middle cerebral arteries during sham or real exposure. In the exposed side the cerebral blood flow velocity, the pulsatility index and the resistance index during sham and real exposure were respectively: [61.9 ± 1.3, 61.7 ± 1.3 cm/s (P = 0.89)]; [0.93 ± 0.03, 0.90 ± 0.02 (P = 0.84)] and [0.58 ± 0.01, 0.58 ± 0.01 (P = 0.96)] at baseline; and [60.6 ± 1.3, 62 ± 1.6 cm/s (P = 0.40)]; [0.91 ± 0.03, 0.87 ± 0.03 (P = 0.97)]; [0.57 ± 0.01, 0.56 ± 0.01 (P = 0.82)] after 20 min of exposure. Twenty minutes of RF exposure to a mobile phone does not seem to affect the cerebral circulation.

Is the Effect of Mobile Phone Radiofrequency Waves on Human Skin Perfusion Non-Thermal?

To establish whether SkBF can be modified by exposure to the radiofrequency waves emitted by a mobile phone when the latter is held against the jaw and ear.

Effect of acute exposure to radiofrequency electromagnetic fields emitted by a mobile phone (GSM 900 MHz) on electrodermal responsiveness in healthy human

Abstract Purpose: The present study aimed to determine the effect of acute exposure to electromagnetic fields (EMF) emitted by a mobile phone on electrodermal activity (EDA) in response to an auditory stimulus. Materials and methods: The EDA of 28 young volunteers was recorded following 26 min of exposure to a GSM mobile phone (900 MHz). Palmar sensors enabled repeat recording of 2 min 45 s in the pre-exposure, exposure and post-exposure phases in response to sound stimuli. Results: The latency, amplitude of skin conductance responses (SCRs), integral of skin conductance response and number of SCRs in response to the auditory stimuli were not modified by exposure. Skin conductance and tonic activity decomposition of the recorded signal were significantly different between the two sessions (p < .0001), but the changes could not be attributed to EMF exposure. There was also a tendency toward a fast reduction in the amplitude and number of electrodermal responses after placement of the mobile phone. In response to successive stimuli, there was a significant difference between the first response and subsequent responses for all variables except latency. Conclusions: Our results showed a decrease in the number of responses and their amplitude as a result of placement of the mobile device and whether it was turned ‘on’ or ‘off’, but there were no changes associated with exposure to GSM radiofrequency waves in this group of volunteers.