K, Röschke J.(1996)
subjects were exposed to RF radiation from a GSM 900 MHz phone, pulsed
at 217 Hz. The power density was 0.5 W/m². The radiation was
from a phone at the head of the bed, 40 cms. from the top of the head.
An EEG was recorded during
sleep. Each subject spent 2 sessions of 3 consecutive nights in the
sleep laboratory. The sessions were separated by an interval of at
least 7 days. The first night was an adaptation night, and on the
second and third nights the subjects were either exposed to the RF
radiation or were sham-exposed, with the order being reversed at the
authors reported that sleep latency (the time it took for a subject
to fall asleep) was reduced. There was a decrease in the duration
of REM sleep and percentage of the total sleep time spent in REM
sleep. There was also an increase in the mean power density in
all bands of the EEG, especially the alpha ones, during REM sleep.
authors carried out two other studies using different power densities,
and found no significant changes (Wagner et al., 1998, 2000).