Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/3082

Title

The effects of electromagnetic fields emitted by GSM mobile phones on human event-related potentials

Author(s)

Wood, Andrew W.;  Hamblin, Denise L.;  Croft, Rodney J.;  Stough, Con

Abstract

OBJECTIVE: This study was designed to examine whether aspects of the Event-Related Potential (ERP) show sensitivity to the electromagnetic fields emitted by mobile phone handsets placed in the normal position next to the face of human volunteers. It was designed as a pilot to a larger study of 120 volunteers currently in progress. METHODS: A GSM mobile phone, either transmitting (0.25 W, 217 Hz modulated, 895 MHz output) or off, was positioned next to the right hemisphere using a cradle. Twelve participants attended two sessions, one week apart. Participants performed the following tasks while they were exposed for 30 minutes to an active mobile phone during one session and a sham condition during the other: (a) auditory oddball (b) visual oddball, (c) card-sorting. Each session lasted up to 2 hours (including setup) and order of exposure condition was counterbalanced. ERPs were recorded from a 62-electrode montage. N100 and P200 latencies and amplitudes were analysed for non-target waveforms, and N200 and P300 latencies and amplitudes were analysed for target waveforms using repeated measures ANOVAs and post-hoc comparisons. Data from groups of electrodes were averaged to form six regions (3 lateral and 2 saggital). RESULTS: Omnibus ANOVAs were carried out in each of: five amplitude and five latency measures for both visual and card-sorting tasks and four amplitude and four latency measures for the auditory task. Within these ANOVAs the three factors were exposure, degree of laterality and degree of sagitality. For post hoc tests, the Bonferroni correction was applied with alpha being reduced for significant sagittal, lateral and sagittal-bilateral effects to .025, .017 and .008 respectively. Several of the post hoc tests were significant at these levels. In real relative to sham exposure auditory N100 amplitude and latency were both reduced, with the reduction larger over midline and right hemisphere sites. P300 latency was delayed in the real exposure condition, but there was no effect of exposure on P300 amplitude or on the P200 or N200 components. Grand means of auditory ERPs for non-targets and targets respectively are shown in Figure 1 for 6 electrode sites. During the visual task, N100 latency was found to increase during real exposure. During the card-sorting task, latency was found to increase during real exposure in right and frontal sites. CONCLUSIONS: The results suggest that there may be an effect of mobile phone exposure on neural activity, particularly in close proximity to the phone. These findings are of assistance in forming specific hypotheses for the larger study. Larger study supported by the National Health and Medical Research Council of Australia

Publication type

Conference abstract

Research centre

Swinburne University of Technology. School of Biophysical Sciences & Electrical Engineering

Source

Proceedings of the 25th Annual Meeting of the Bioelectromagnetics Society, 22-27 June 2003, Maui, Hawaii, USA

Publication year

2003

Publisher URL

Proceedings of the 25th Annual Meeting of the Bioelectromagnetics Society, 22-27 June 2003, Maui, Hawaii, USA

Publisher URL

http://bioelectromagnetics.org/pubs.php#abstracts

Copyright

© The Bioelectromagnetics Society