Radiation and Sleep
study conducted with young men at the University of Zurich, which
was published in Neuroscience Letters 1999, reported intermittent
exposure to 900 MHz
radiation reduced the amount of time spent awake during the night
after first falling asleep. Changes also occurred in the electroencephalogram
recordings of the subjects' brain waves. "More details of the study
by Borbely et al can be found in "Research
- Clinical -EEG"
UK Government Appoints
Independent Expert Group on Mobile Phones
In March, 1999, the UK Minister for Public Health asked the National
Radiological Protection Board to set up an independent expert group
on mobile phones. The terms of reference were: "To consider present
concerns about the possible health effects from the use of mobile
phones, base stations and transmitters, to conduct a rigorous assessment
of existing research and to give advice based on the present state
of knowledge. To make recommendations on further work that should
be carried out to improve the basis for sound advice."
Collectively, the Expert Group has knowledge in epidemiology
and experimental biology related to exposures to electromagnetic
fields and radiofrequencies, social sciences, risk perception, and
legal issues. In addition to members with lay interests, the Expert
Group represents a broad spectrum of medical and scientific interests
including oncology, physics, statistics and neurophysiology. The
World Health Organisation and the NRPB Advisory Group on Non-ionising
Radiation also have representatives amongst the members group.
The group issued a public call for written evidence and has held
four public meetings between November and January, with another
planned for February. The Expert Group has created a website - www.iegmp.org.uk/index.html
RF radiation and brain
function in humans
and his colleagues conducted a study that tested the effect of RF
radiation exposure at cell phone frequency on brain function. They
tested two groups of 18 subjects. The subjects wore a headset-mounted
physical model of a phone, which was placed in the normal position
with the antenna situated adjacent to the left side of the head.
During the study three conditions were used - the phone was not
activated; there was a 915 MHz signal like an analog signal; and
there was a 915 MHz signal which simulated a digital signal.
The subjects participated in 15 different performance tests spanning
four categories - accuracy on memory tests, speed on memory tests,
accuracy on reaction/attention tests, and speed on reaction/attention
tests. In both groups the only test affected was the choice reaction
time, which involved hitting a "yes" or "no" button as quickly as
possible after the corresponding word flashed on a computer screen.
Amongst the choice reaction time tests the analog exposure had a
mean time of 373.4 mseconds, compared with 384.4 mseconds for digital
exposure, and 387.9 mseconds for the controls. There were no significant
changes in word, number or picture recall, or spatial memory.
The authors suggested that the decreased reaction time might be
due to an effect on the angular gyrus, which is an area of the brain
lying directly beneath the antenna position. This gyrus connects
the visual and speech centres. Preece speculated that the resulting
effect was due to mild localised heating, which could cause expansion
of the blood vessels and improved oxygenation in the area.
Preece AW, Iwi G, Davies-Smith A, Wesnes K, et al. (1999): Effect
of a 915-MHz simulated mobile phone signal on cognitive function
in man. Int J Radiat Biol 75:447-456.