Effect of GSM-900 and -1800 signals on the skin of hairless rats. I: 2-hour acute exposures.

PURPOSE: The acute influence on the skin of non-ionizing electromagnetic fields in the radiofrequency (RF) range used in mobile telephony has not been widely studied to date. The purpose of this work was to determine whether the cells of hairless rat skin are affected by acute local exposure to Global System for Mobile Communication: GSM-900 or -1800 RadioFrequency Radiation (RFR). MATERIALS AND METHODS: Hairless female rats were exposed or sham-exposed for 2 h to GSM-900 or -1800 signals, using a loop-antenna located on the right part of the rats' back. The local Specific Absorption rate (SAR) at skin level was ca. 5 W/kg (5.8+/-0.4 and 4.8+/-0.4 W/kg at 900 and 1800 MHz, respectively). A skin biopsy was done at the end of the experiment not only at the location of exposure, but also on the symmetrical part of the back. RESULTS: Analysis of skin sections using Hematoxylin Eosin Saffron (HES) coloration showed no difference in skin thickness or apparent cell toxicity (with no sign of cellular necrosis) among the animal groups. Histological analysis of the epidermis showed that the ratio between cells expressing the antigen Ki-67 (cellular proliferation marker) and the total number of cells remained within the range of normal proliferation ratio for the exposed side of the animal. No Ki-67 labelling was observed at the dermis level. Results on filaggrin, collagen and elastin levels also showed an insignificant influence of RFR. CONCLUSIONS: These results do not demonstrate any major physical and histological variations at skin level induced by RFR used in mobile telephony.

Effects of GSM-900 microwaves on the experimental allergic encephalomyelitis (EAE) rat model of multiple sclerosis.

The effects of acute exposure to GSM-900 microwaves (900 MHz, 217 Hz pulse modulation) on the clinical parameters of the acute experimental allergic encephalomyelitis (EAE) model in rats were investigated in two independent experiments: rats were either habituated or nonhabituated to the exposure restrainers. EAE was induced with a mixture of myelin basic protein and Mycobacterium tuberculosis. Female Lewis rats were divided into cage control, sham exposed, and two groups exposed either at 1.5 or 6.0 W/kg local specific absorption rate (SAR averaged over the brain) using a loop antenna placed over their heads. There was no effect of a 21 day exposure (2 h/day) on the onset, duration, and termination of the EAE crisis.