Does the Brain Detect 3G Mobile Phone Radiation Peaks? An Explorative In-Depth Analysis of an Experimental Study

<div><p>This study aimed to investigate whether third generation mobile phone radiation peaks result in event related potentials. Thirty-one healthy females participated. In this single-blind, cross-over design, a 15 minute mobile phone exposure was compared to two 15 minute sham phone conditions, one preceding and one following the exposure condition. Each participant was measured on two separate days, where mobile phone placement was varied between the ear and heart. EEG activity and radiofrequency radiation were recorded jointly. Epochs of 1200ms, starting 200ms before and lasting until 1000ms after the onset of a radiation peak, were extracted from the exposure condition. Control epochs were randomly selected from the two sham phone conditions. The main a-priori hypothesis to be tested concerned an increase of the area in the 240-500ms post-stimulus interval, in the exposure session with ear-placement. Using multilevel regression analyses the placement*exposure interaction effect was significant for the frontal and central cortical regions, indicating that only in the mobile phone exposure with ear-placement an enlarged cortical reactivity was found. Post-hoc analyses based on visual inspection of the ERPs showed a second significantly increased area between 500-1000ms post-stimulus for almost every EEG location measured. It was concluded that, when a dialing mobile phone is placed on the ear, its radiation, although unconsciously, is electrically detected by the brain. The question of whether or not this cortical reactivity results in a negative health outcome has to be answered in future longitudinal experiments.</p></div

Mean radiation intensity of exposed and sham exposed epochs ± 2 standard error of the mean.

<p>The 4 grand averages of the non-conscious evoked related potentials of the twelve different locations are depicted in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125390#pone.0125390.g002" target="_blank">Fig 2</a>. A visual inspection makes clear that the pre-stimulus baseline area (-200-0ms) does not show remarkable differences between the four grand averages. In the post-stimulus area, the exposed ear session is the only condition which has a distinct course. This effect is especially prominent in the 240–500ms frontal and central post-stimulus areas. Except Fz and F4, in which a P300-like peak can be detected, the morphology is not similar to that of most conscious ERP responses: a N200 is missing and the ERP has a smaller amplitude in general. Moving from frontal to occipital, the ‘P300 peak’ seems to diminish and a later effect, from 500–1000ms, becomes more noticeable. These are no obvious visual left-right hemispherical differences. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125390#pone.0125390.g003" target="_blank">Fig 3</a> shows the topography of the grand averages.</p

Topography of EEG activity.

<p>In <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125390#pone.0125390.t002" target="_blank">Table 2</a> the t-values (and their corresponding p-values) of the main outcome variable are presented: the interaction effect between placement and exposure. As expected, the baseline (-200-0ms) never reaches significance. The same applies for the first post-stimulus period ranging from 0 to 240ms. In the critical range from 240–500ms the frontal and central regions show a significant elevation for the ear exposed condition compared to the other conditions. Based on the visual inspection of the grand averages, it was decided to perform a series of post hoc analyses on the ERFIA range of 500–1000ms post-stimulus. A significant elevation for the exposed ear condition was found for all electrodes except for F4 and C4. Finally, when correcting for multiple testing (12 locations) by means of the Bonferroni procedure (p_{critical-corrected} (0.05/12) = 0.004), an asterisk is placed in column ‘C’ when the p-value remains significant.</p

Event Related Fixed Interval Area (per 20ms) grand averages in twelve EEG locations.

<p>Event Related Fixed Interval Area (per 20ms) grand averages in twelve EEG locations.</p

Experimental design.

<p>Experimental design.</p

Left midline right.

<p>Each symbol represents the p-value of the main predictor ‘radiation’ in the relevant area. * in the graph indicates a significant left-right contrast. Below the graph a table depicts the p-values. * in the table represents a significant q-value (q<0.05) after correction for multiple testing using the false discovery rate (FDR) method. ** significant q-value (q<0.01) after correction for multiple testing. All values of this table were included for the FDR computation.</p

EEG Changes Due to Experimentally Induced 3G Mobile Phone Radiation

<div><p>The aim of this study was to investigate whether a 15-minute placement of a 3G dialing mobile phone causes direct changes in EEG activity compared to the placement of a sham phone. Furthermore, it was investigated whether placement of the mobile phone on the ear or the heart would result in different outcomes. Thirty-one healthy females participated. All subjects were measured twice: on one of the two days the mobile phone was attached to the ear, the other day to the chest. In this single-blind, cross-over design, assessments in the sham phone condition were conducted directly preceding and following the mobile phone exposure. During each assessment, EEG activity and radiofrequency radiation were recorded jointly. Delta, theta, alpha, slowbeta, fastbeta, and gamma activity was computed. The association between radiation exposure and the EEG was tested using multilevel random regression analyses with radiation as predictor of main interest. Significant radiation effects were found for the alpha, slowbeta, fastbeta, and gamma bands. When analyzed separately, ear location of the phone was associated with significant results, while chest placement was not. The results support the notion that EEG alterations are associated with mobile phone usage and that the effect is dependent on site of placement. Further studies are required to demonstrate the physiological relevance of these findings.</p></div

Radiation effects on EEG: ear and heart sessions analyzed separately.

<p>Each symbol represents the p-value of the main predictor ‘radiation’ in the relevant area. Below the graph a table depicts the p-values. * significant q-value (q<0.05) after correction for multiple testing using the false discovery rate (FDR) method. ** significant q-value (q<0.01) after correction for multiple testing. All values of this table were included for the FDR computation.</p

Interaction variable placement*radiation.

<p>Each symbol represents the p-value of the interaction variable in the relevant area. Below the graph a table depicts the p-values. * significant q-value (q<0.05) after correction for multiple testing using the false discovery rate (FDR) method. ** significant q-value (q<0.01) after correction for multiple testing. All values of this table were included for the FDR computation.</p

CONSORT flow chart

<p>CONSORT flow chart</p