Decupaje: Wi-fi: should we be worried?

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*4 Wi-fi: should we be worried?*
Concern about the safety of wireless networks is mounting, with people
blaming everything from headaches to cancer on the technology
/ (Nicki Daniels)
/
It started as a low murmur, and has now risen to a persistent hum.
Thanks partly to a lively correspondence in the pages of The Times, the
debate about the safety of wireless networks is gathering momentum. Is
this new technology a threat to human health comparable to smoking — as
some campaigners claim — or an electric storm in a teacup?
Wireless networks — known as wi-fi or wLAN (wireless local area network)
— are increasingly used in schools, offices and other public places to
connect computers and laptops to the internet using radiofrequency
transmitters with no need for complex cabling. In future, whole town
centres will be transformed into wi-fi "hot spots", enabling people to
access the internet wherever they are through hand-held devices,
including mobile phones. Indeed, Milton Keynes, Norwich and the borough
of Islington, in North London, already have this WiMax technology.
It has taken the public a while to wake up to the idea that wireless
transmitters could be less than benign. As with mobile phones, we first
embrace the liberating new technology and only later ask the awkward
questions. Perhaps, as with pharmaceuticals, the order should be
reversed. The official line on the health implications of wi-fi is that
exposure to low level electromagnetic radiation from wireless networks
is well below recommended levels and that there is no evidence of risk.
But despite these soothing words, the groundswell of concern is
mounting, with some people blaming everything from headaches to cancer
on exposure to radio-frequency fields.
As reported in this newspaper, a number of schools have dismantled their
wireless networks after lobbying from worried parents, and others are
under pressure to follow suit. In Austria the public health department
of Salzburg has advised schools and kindergartens not to use wLAN or
cordless phones. Lakehead University in Ontario, Canada, which has 7,400
students, has removed wi-fi because of what its Vice-Chancellor, Dr Fred
Gilbert, calls "the weight of evidence demonstrating behavioural effects
and physiological impacts at the tissue, cellular and cell level".
Some experts have also expressed concerns. In September, 30 scientists
from all over the world signed a resolution calling for a "full and
independent review of the scientific evidence that points to hazards
from current electromagnetic field exposure conditions worldwide."
Closer to home, the Irish Doctors Environmental Association (IDEA) has
asked its country's Government to carry out "a full assessment of the
health impacts of electromagnetic radiation".
"There has been no research specifically looking at the effects of
wireless networks on human health," admits Alasdair Philips, the
scientific and technical director of the lobby group Powerwatch. "But I
have seen enough anecdotal material to be convinced that some people are
affected by them."
David Dean, 43, a councillor in Merton, South London, and the managing
director of a publishing company, describes himself as a human antenna.
"The moment I go into people's houses I know whether they have wi-fi
because my head starts to buzz. I had to leave my last job because I
couldn't stand up for more than ten minutes in the office and my boss
would not remove the wi-fi. My heart raced, I had double vision and
really bad headaches. It felt as though my head was in an arm lock.
Twice I have been into homes where the children were screaming monsters.
After I suggested to the parents that they turn off the network for two
days, the kids were transformed."
Anxiety about wi-fi has focused on the effect of electromagnetic
radiation on children because they have thinner skulls, less fully
developed nervous systems and will undergo a lifetime of exposure to
cellphone technology.
In his report on mobile phones, Professor Sir William Stewart, the
chairman of the Health Protection Agency (HPA), acknowledged that
radiation below guideline levels, while thought to be safe, may have
effects on the body. He therefore advocated a precautionary approach,
including close monitoring of radiation from masts near schools and a
recommendation that the beam of greatest intensity from a mast should
not fall within the grounds of a school.
"The emissions from wireless networks are very similar to those from
mobile phone base stations in terms of frequency and signal modulation,"
says Philips, who, it must be said, runs a company selling
electromagnetic radiation detectors and blockers. "Many published
reports have shown ill-health affects apparently associated with living
and working close to mobile phone masts. In a Latvian study of 966
children, motor function, memory and attention were significantly worse
in the group exposed to radiation from a pulsed radio location station.
The exposure levels were low, but similar to those that children in
classes with wLANs will be exposed to."
Dr Michael Clark, of the HPA, says published research on mobile phones
and masts does not add up to an indictment of wi-fi. "All the expert
reviews done here and abroad indicate that there is unlikely to be a
health risk from wireless networks," he says. "The few studies on mobile
phone masts that have appeared in peer-reviewed journals claiming to
observe health effects are not at all conclusive. The real problem is
deciding what level of precaution is appropriate.
"When we have conducted measurements in schools, typical exposures from
wi-fi are around 20 millionths of the international guideline levels of
exposure to radiation. As a comparison, a child on a mobile phone
receives up to 50 per cent of guideline levels. So a year sitting in a
classroom near a wireless network is roughly equivalent to 20 minutes on
a mobile. If wi-fi should be taken out of schools, then the mobile phone
network should be shut down, too — and FM radio and TV, as the strength
of their signals is similar to that from wi-fi in classrooms."
Philips is not reassured: "Electromagnetic radiation exposure guidelines
in the UK are designed to protect against gross heating effects. They
are not meant to protect against long-term exposure to low levels of
pulsing microwaves, such as laptops emit when downloading. We believe
that these interfere with the body's own normal internal electrical and
electro-chemical signalling systems, leading to serious health problems,
and growing children may be more affected than adults, whose cells are
not changing as rapidly."
One of the problems in conducting research is that not everybody is
affected by electromagnetic radiation in the same way. "A growing,
consistent body of literature demonstrates that a subgroup of the
population appears to suffer distressing symptoms when exposed to this
type of radiation," says Dr Elizabeth Cullen, of IDEA. Sleep
disturbances, depression, blurred vision, heart and breathing problems,
nausea and headache are among the most common symptoms.
Up to 5 per cent of the population is thought to have this sensitivity,
which is recognised in Sweden as a disability. In Stockholm sufferers
can have their homes adapted to remove or screen out sources of
electromagnetic radiation. If this proves ineffective, they can even
rent council-owned cottages in areas of low radiation.
(...=
http://www.canceractive.com/cancer-active-page-link.aspx?n=1538
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