The increasing use of mobile telephones has raised concerns about possible health hazard effects. The most widely used GSM (global system for mobile communication) cellular phones operate with carrier frequencies in the near Gigahertz range. Continuous and pulsed microwave exposure of the brain has been reported to modulate neuronal activity in vivo and in vitro, and to influence signal transduction pathways. These responses may be associated with alterations in gene expression, potentially preceding degenerative processes of the CNS. Therefore, the effects of electromagnetic field exposure on the expression of immediate early genes (lEG) and the stress gene hsp 70 were investigated at the transcriptional and translational level.
Acute high intensity microwave exposure of immobilized rats up to SAR 10 Wlkg for 4 h induces some minor stress response on the mRNA level but does not result in abnormalities of the corresponding protein products. Our data, therefore, do not support the hypothesis that microwaves emitted by mobile telephones have a major impact on the expression of lEGs and stress genes. However, in the present study the effects of chronic microwave exposure or of the combined exposure with other noxious conditions were not assessed. Further experiments are, therefore, required to dismiss completely the possibility that mobile telephony poses a health risk to the central nervous system.