Tsurita G, Nagawa H, Ueno S, et al. (2000)
The authors investigated the effects of 1439 MHz TDMA RF radiation on the permeability of the blood-brain barrier (BBB), on morphological changes in the brain, and on body-mass fluctuations. The peak SAR of the brain was 2 W/kg, and the average whole body SAR was 0.25 W/kg. The rats were exposed for either two or four weeks. In each protocol exposure for one hour per day for five consecutive days was followed by two days of rest. Six rats were exposed for 2 weeks and six for four weeks and they were compared to an equal number of sham-exposed rats, and also to control rats, which were neither placed in the exposure tubes nor received EM exposure.
The changes in the permeability of the BBB were investigated by Evans blue injection method and by immunostaining of serum albumin. The RF radiation had no effect on the BBB. Similarly, exposed animals showed no changes in cerebellum morphology or in body mass.
This study is in contrast to other studies that did show a change in the BBB after exposure to microwaves. Tsurita et al. consider that these studies had technical problems, including an increase in the temperature of the animals, that could account for the observed results.