Experimental Study on Possible Effects of Radiofrequency (RF) Signal Characteristics Used for the TETRA Standard on Cognitive Functions in Healthy Subjects

Background

Several international studies on the influence of electromagnetic fields from mobile communications on cognitive performance and brain function during waking and sleep were performed during the last years. No health relevant effects were found below the maximum exposure of 2 Watt per kilogram (W/kg), which applies for the use of mobile devices by the public.

In Germany a new digital radio communication network for security authorities and organisations based on the TETRA standard is set up at present. TETRA (Terrestrial Trunked Radio) uses a frequency band around 400 MHz and has been much less investigated than public mobile communications. The results of the German Mobile Telecommunication Research Programme showed a higher temperature increase of the exposed tissue at 400 MHz than at the frequencies used by mobile phones. For occupational groups using mobile TETRA devices (as for example policemen and firemen), a local exposure up to 10 W/kg is permitted. Possible effects of electromagnetic fields of mobile TETRA devices will be investigated in humans to further reduce scientific uncertainties concerning the impact of the digital radio for security authorities.

Objective

In the present study, possible effects of an exposure with TETRA signals (sham, SAR values of 1.5 W/kg and 6 W/kg) on the brain activity of humans are investigated. A volunteer study is performed on healthy young men, preferentially from the group of potential users who will be occupationally exposed.