Effect of 450 MHz Microwave Modulated with 217 Hz on Human EEG in Rest

Bachmann, Maie; Säkki, Maksim; Kalda, Jaan; Lass, Jaanus; Tuulik, Viiu; Hinrikus, Hiie

doi:10.1007/s10669-005-4279-5

Cited by 14 publications

(16 citation statements)

References 17 publications

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“…This result is in agreement with the findings reported recently, that the GSM mobile phone radiation increased the EEG power mainly in the alpha frequency band [Huber et al, 2002;Curcio et al, 2005]. Our previous results suggested that the 450 MHz microwave modulated at 217 Hz increased the EEG energy and the effect was stronger on the EEG beta rhythm in parietal and temporal regions [Bachmann et al, 2005b]. It is interesting to note that the effect caused by a chemical stressor results in similar changes in the resting EEG; an increased beta absolute power has also been observed in alcohol-dependent subjects [Rangaswamy et al, 2002].…”

Section: Discussionsupporting

confidence: 94%

Effect of low frequency modulated microwave exposure on human EEG: Individual sensitivity

Hinrikus

Bachmann

Lass

et al. 2008

Bioelectromagnetics

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The aim of this study was to evaluate the effect of modulated microwave exposure on human EEG of individual subjects. The experiments were carried out on four different groups of healthy volunteers. The 450 MHz microwave radiation modulated at 7 Hz (first group, 19 subjects), 14 and 21 Hz (second group, 13 subjects), 40 and 70 Hz (third group, 15 subjects), 217 and 1000 Hz (fourth group, 19 subjects) frequencies was applied. The field power density at the scalp was 0.16 mW/cm(2). The calculated spatial peak SAR averaged over 1 g was 0.303 W/kg. Ten cycles of the exposure (1 min off and 1 min on) at fixed modulation frequencies were applied. All subjects completed the experimental protocols with exposure and sham. The exposed and sham-exposed subjects were randomly assigned. A computer also randomly assigned the succession of modulation frequencies. Our results showed that microwave exposure increased the EEG energy. Relative changes in the EEG beta1 power in P3-P4 channels were selected for evaluation of individual sensitivity. The rate of subjects significantly affected is similar in all groups except for the 1000 Hz group: in first group 3 subjects (16%) at 7 Hz modulation; in second group 4 subjects (31%) at 14 Hz modulation and 3 subjects (23%) at 21 Hz modulation; in third group 3 subjects (20%) at 40 Hz and 2 subjects (13%) at 70 Hz modulation; in fourth group 3 subjects (16%) at 217 Hz and 0 subjects at 1000 Hz modulation frequency.

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Section: Discussionsupporting

confidence: 94%

Effect of low frequency modulated microwave exposure on human EEG: Individual sensitivity

Hinrikus

Bachmann

Lass

et al. 2008

Bioelectromagnetics

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“…This is somewhat different from what has been observed for the modulation frequency 7 Hz, when the sign of the departure was always negative (corresponding to increased variability) (Bachmann et al 2005a). However, the outcome of a study at modulation frequency 217 Hz, in which for half of the subjects the computed LDLVP weighted area decreased and for another half it decreased (Bachmann et al 2005b), coincides with current results at 40 Hz. The S-parameter measures exceeded the limit of significant deviation from zero hypothesis also at modulation frequency 40 Hz in beta2 frequency band (Table 1), providing two significant cases out of 15, that is 13.3%.…”

Section: Discussioncontrasting

confidence: 92%

“…The results reported in our previous study with 7 Hz modulated microwave lead to the conclusion that the effect appears in time variability (Bachmann et al 2005a), while the next study concerning modulation frequency 217 Hz concluded that the effect is rather in intensity (Bachmann et al 2005b).…”

Section: Discussionmentioning

confidence: 78%

Individual changes in human EEG caused by 450 MHz microwave modulated at 40 and 70 Hz

et al. 2007

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This study was aimed to investigate the changes in the human electroencephalographic (EEG) signal caused by modulated low-level microwaves. The 450 MHz microwave exposure modulated at 40 Hz and 70 Hz frequencies was applied to a group of 15 volunteers. The field power density at the scalp was 0.16 mW/cm 2 . Ten cycles of the exposure (1 min on and 1 min off) at both modulation frequencies were applied. Analysis of the EEG signal was performed using three different methods: nonlinear method of scaling analysis for length distribution of low variability periods (LDLVP), relative changes in EEG energy (S-parameter) and beta ratio (H-parameter). The analysis revealed significant changes caused by microwave for the whole group (H-parameter method). The exposure caused increase of the EEG beta power (S-parameter method). Statistically significant changes in EEG were detected for four subjects (26.7%) at 40 Hz modulation frequency (LDLVP method).

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“…This suggests that different modulation techniques (e.g., temporal power variation, modulation frequency) in different mobile phone systems may be a biologically relevant factor [Pedersen and Andersen, 1999;Bachmann et al, 2005;Hinrikus et al, 2007Hinrikus et al, , 2008. In addition, the majority of null findings in the literature may be due to the low power level of mobile phone radiation because most studies were designed to give local SAR values at or near the permitted limits.…”

Section: Discussionmentioning

confidence: 99%

Effects of mobile phone electromagnetic fields: Critical evaluation of behavioral and neurophysiological studies

Kwon

Hämäläinen

2010

Bioelectromagnetics

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For the last two decades, a large number of studies have investigated the effects of mobile phone radiation on the human brain and cognition using behavioral or neurophysiological measurements. This review evaluated previous findings with respect to study design and data analysis. Provocation studies found no evidence of subjective symptoms attributed to mobile phone radiation, suggesting psychological reasons for inducing such symptoms in hypersensitive people. Behavioral studies previously reported improved cognitive performance under exposure, but it was likely to have occurred by chance due to multiple comparisons. Recent behavioral studies and replication studies with more conservative statistics found no significant effects compared with original studies. Neurophysiological studies found no significant effects on cochlear and brainstem auditory processing, but only inconsistent results on spontaneous and evoked brain electrical activity. The inconsistent findings suggest possible false positives due to multiple comparisons and thus replication is needed. Other approaches such as brain hemodynamic response measurements are promising but the findings are few and not yet conclusive. Rigorous study design and data analysis considering multiple comparisons and effect size are required to reduce controversy in this important field of research.

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Effect of 450 MHz Microwave Modulated with 217 Hz on Human EEG in Rest

Cited by 14 publications

References 17 publications

Effect of low frequency modulated microwave exposure on human EEG: Individual sensitivity

Effect of low frequency modulated microwave exposure on human EEG: Individual sensitivity

Individual changes in human EEG caused by 450 MHz microwave modulated at 40 and 70 Hz

Effects of mobile phone electromagnetic fields: Critical evaluation of behavioral and neurophysiological studies

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