WIRELESS NETWORKS
http://www.powerwatch.org.uk
4th November 2003
Wireless Local Area Networks (WLANs) and Bluetooth
We are very concerned about the use of WLANs in internet cafés, hotels,
schools, colleges and other public and private places. These emit a constant
stream of pulsing low-level microwaves that we believe will cause some people
to experience adverse health effects. Each computer that logs onto the WLAN
network also emits pulsing microwaves so that in a classroom or an internet
café the background electropollution level rises considerably. Here is a
personal story from a UK medical doctor (we have full contact details):
"Last July, out of the blue I developed a disruption to my heart rhythm. As a
qualified Doctor I considered possible causes, such as caffeine intake,
tiredness, high blood pressure, or the onset of menopausal symptoms. Being
slight of frame, with normal to low blood pressure and excellent general
health, I reasoned the ectopic beats and variable pulse rate would probably go
away with a reduction in my tea and coffee, and a little rest. Over the next 6
weeks, the arrhythmia continued to the point where I was aware of it for the
majority of the day. I also experienced disturbance to my sleep, waking in the
early hours and then being unable to fall asleep again.
From the tightness of my upper chest I knew I was not getting enough
oxygen. I was very reluctant to consult my GP, aware of the investigations it
would initiate, and also of the many drugs in the armoury for treating
arrhythmias with their multitude of side effects. There was no precipitating
factor I could identify that would afflict a fit 49 year old, with no
pre-existing heart orrespiratory problems, in this way.
On the verge of making an appointment with my GP, I linked the onset of my
symptoms to our acquisition of a laptop with a wireless modem (NET GEAR and is
a Wireless ADSL Modem Gateway DG824M) situated in the hallway. This "base
station" had been transmitting microwaves 24 hours/day at a frequency of
2.4GHz, extending to a radius of 150 feet. These (and similar) are being
placed in the foyers of airports, and hotels, in GP's surgeries, coffee shops
and student halls of
residence, so individuals can use their laptops with the minimum of fuss.
We disconnected the wireless base station, replacing it with a fixed line.
Within 3 weeks I was totally free of any abnormality as detected by pulse or
symptoms, my sleep settled back to normal, as did my energy. On consideration,
during the summer others in my family of 5 have been abnormally fatigued with
disturbed sleep patterns. My 18 year old daughter had an episode of extreme
dizziness lasting a whole day after close contact with the transmitter. My 22
year old son similarly experienced vomiting and vertigo, disabling him for a
day after spending 2 hours within feet of the apparatus. If this is how it
affects a healthy family of adults over a short period of time, what will be
the consequences on a cross-section of the general population, let alone those
with heart problems or pacemakers, the pregnant and the young? What is the
real price of convenience?
F.F. MB ChB"
According to various European groups (e.g. FEB) for the electrically
sensitive, some people are disturbed by pulsing microwave fields as low as
0.01 volts per metre. The recent Dutch Government funded TNO study into base
station signals (see www.powerwatch.org.uk website for details) found that
there were statistically significant cognitive and adverse well-being changes
in 'ordinary' people subjected to just 20 minutes exposure of 1 volt/metre of
3G base station signal. A typical minimum 'safety factor' would be 10, so that
means a precautionary maximum of 0.1 volts per metre or less. WLAN nodes
typically emit either up to 100 mW or 500 mW. To keep to a maximum of 0.1 V/m
would mean keeping at least (respectively) 17 or 40 metres away from the node.
This is usually impractical.
WLAN cards in computers (including laptops with built in WLAN capability)
typically emit 1 to 2.5 mW. This will exceed the suggested 0.1 V/m
precautionary maximum of pulsing microwaves for over one metre around the
computer and produce up to 1 V/m at 40 cm from the keyboard and screen where
the person (e.g. school pupil) will be working. Any classroom with 10, or so,
WLAN computers will be awash with a sea of pulsing microwave pollution.
Sensitive people will be adversely affected.
The Swedish FEB website ( www.feb.se ) gives some details of the problems of
electrosensitivity (ES). From the few formal scientific investigations that
have been done into this it appears that people who are sensitive to other
things (e.g. chemicals, pollen, noise, etc) are also more likely to sensitive
to electromagnetic fields.
They suggest that between 3% and 10% of people exhibit symptoms of
electrosensitivity (undiagnosed as to their cause in most cases).
Typical problems include headaches, loss of concentration, attention deficit,
hyperactivity, poorly functioning immune system, unusual levels of fatigue and
general lack of well-being as defined by the World Health Organisation.
We do not have a problem with traditional wired LAN networks (e.g. Ethernet,
etc), and that is what we strongly recommend is installed in schools and
colleges. However, increasingly, organisations are installing WLANs as they
see them as cheaper (because fixed wiring is not necessary) and more versatile
as one fixed node can often cover several classrooms and pupils can carry
their WLAN enabled laptops from class to class. If schools plan their
internet and intranet (the schools local network) access sensibly it should
not be necessary to have large numbers of networked computers in most
classrooms.
It is often said that most teenagers have and use their own mobile phones.
This is true, but it is also against current UK Government Department of
Health advice for under 16 year olds. We also believe that mobile phone use is
affecting the behaviour and attention span of young people, though there have
not been formal scientific studies into this. Two scientific studies have
shown cognitive changes in people using mobile phones - it has acted as a
brain activity stimulant in the short term (one 20 minute exposure), but
concerns were expressed than ongoing stimulation could well produce adverse
effects in the longer term. However most youngsters mainly use their handsets
for sending and receiving SMS text messages and so have only occasional
exposure. Sitting for several periods a day in a room of WLAN enabled
computers is a much more serious chronic exposure.
If schools insist on installing wireless networks, then we say that is
essential that teaching and care staff are formally warned to look out for
adverse changes among pupils and a formal reporting system implemented so that
the school keeps records of any perceived adverse effects.
We also strongly recommend that there should be extra classrooms set aside
where pupils who are sensitive to pulsing microwave electropollution may work
free from the polluting WLAN connected laptops and wall or ceiling mounted
WLAN nodes. It is NOT adequate just to place them in one corner of the
classroom - they will still be irradiated to an unacceptable level.
The following table showing increasing levels of concern (similar to guidance
for WLAN frequencies of 2.4 and 5 GHz). The "equivalent speed" is for easy
comparison with the Salzburg 1998 Guidance.
1800 MHz (1.8 GHz) Public Exposure Guidelines
Equivalent c.f. speed
(abbreviated table)
uW/m2
Volts/m
m.p.h.
ICNIRP (1998), WHO
9 000 000
58
2847
Italy, Russia, PRChina, Switzerland, Lichtenstein
100 000
6
300
Belgium (Wallonia), Luxembourg
24 000
3
147
Italy (single frequency), Salzburg 1998 (sum GSM)
1 000
0.6
30
EU-Parl, GD Wissenschaft, STOA GSM (2001)
100
0.2
9
Salzburg GSM/3G etc outside houses (2002)
10
0.06
3
Salzburg GSM/3G etc inside houses (2002)
1
0.02
1
Bürgerforum BRD proposal, waking areas (1999)
1
0.02
1
Written by Alasdair Philips, Director of Powerwatch.
