Effects of GSM 900 MHz signal on the spectral power in resting electroencephalogram

Context : Mobile phone (MP) has become a popular tool of communication and central component of modern family life. This extensive use of MP is paired to the higher exposure to radiofrequency and raises a question about the health effects of radiofrequencies emitted by the mobile phones. Objectives : The aim of this study was to examine the potential impact of GSM RF exposure on the brain electrical activity. Analysis were focused on the alpha, theta and delta bands of the resting EEG. This study was conducted in awake volunteers under two different conditions: open and closed eyes. Participants and methods : Twenty-six healthy volunteers participated in the experiment (13 females and 13 males, mean age = 23.5 ± 3.1 years). They attended two EEG recording sessions in a crossover, randomized, double-blind and counterbalanced design. During each session, the subject was exposed to 26 min of sham or real GSM RF exposure. Each recording session was composed of 3 experimental conditions: pre-exposure, exposure and post-exposure. Recording consisted of resting EEG open eyes (3 min) and resting EEG closed eyes (3 min). A paired sample permutation test based on t-statistics was used to investigate the difference between sham/exposure conditions. Results : Comparison between the sham session and 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 post-exposure session (P < 0.0001). No differences were reported between the two sessions on the effect of GSM 900MHz on the theta or delta band. In conclusion, these results suggest that GSM-EMFs of a mobile phone affect the alpha band within spectral power of resting human EEG