Biological and morphological effects on the brain after exposure of rats to a 1439 MHz TDMA field

We investigated the effects of exposure to a 1439 MHz TDMA (Time Division M ultiple Access) field, as used in cellular phones, on the permeability of t he blood-brain barrier (BBB), on the morphological changes of the brain, an d on body-mass fluctuations. Male Sprage-Dawley (SD) rats were divided into three groups of eight rats each. The rats in the EM(+) group, which had th eir heads arrayed in a circle near the central antenna of an exposure syste m, were exposed to a 1439 MHz field for one hour a day. The rats in EM(-) g roup were also in the exposure system, however, without high-frequency elec tromagnetic wave (HF-EMW) exposure. The animals in the control group were n either placed in the system nor exposed to HF-EMWs. The exposure period was two or four weeks. The energy dose rate peaked at 2 W/kg in the brain; the average over the whole body was 0.25 W/kg. The changes in the permeability of BBB were investigated by Evans blue injection method and by immunostain ing of serum albumin. HF-EMWs had no effect on the permeability of BBB. The morphological changes in the cerebellum were investigated by assessing the degeneration of Purkinje cells and the cell concentration in the granular layer. No significant changes were observed in the groups of rats exposed t o HF-EMWs for two or four weeks. Averaged body masses were not affected by HF-EMWs exposure. In conclusion, a 1439 MHz TDMA field did not induce obser vable changes in the permeability of the BBB, morphological changes in the cerebellums, or body mass changes in rats, as evaluated by the conventional methods. (C) 2000 Wiley-Liss. Inc.