- Children born close to high-voltage overhead power lines
are more likely to be diagnosed with leukaemia, according to the results
of a major Government-funded study published today.
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- Researchers find that those whose childhood homes are
within 200 metres of a power line have an almost 70 per cent greater risk
of being diagnosed with leukaemia.
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- However, they stress that they have not established the
cause of the increased risk and that it could be due to other factors,
such as differences in wealth between those who live near power lines and
those who do not.
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- They say that if the 275 kilovolt (kV) and 400kV national
grid lines investigated in the study are indeed the cause of the rise,
they would be responsible for approximately one per cent of leukaemia cases
in England and Wales, or around five cases per year.
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- Campaigners claim that lower voltage regional power lines,
which operate at 132kV, might have the same effect, in which case the number
of leukaemia cases linked to electricity transmission could be 10 times
higher.
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- The study, the largest of its kind to date, is published
today in the British Medical Journal. It analyses 29,081 people from England
and Wales who were diagnosed with cancer aged under 15 between 1962 and
1995. They are compared with the same number of healthy individuals, matched
for sex and year and area of birth.
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- Researchers calculated the distance from each person's
home at birth and the nearest high-voltage overhead line.
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- For those born within 200 metres of a power line, the
risk of leukaemia is 69 per cent greater than for those born more than
600 metres away. Those between 200 metres and 600 metres from a power line
are 23 per cent more likely to have been diagnosed with leukaemia than
those whose homes were more than 600 metres away. No increased risks are
found for other types of childhood cancer. Dr Gerald Draper, of the Oxford
Childhood Cancer Research Group, led the research. He says: "The increased
risk of leukaemia up to 600 metres from the high voltage power was surprising
in the view of the very low level of magnetic fields at these distances.
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- "There is no accepted biological mechanism to explain
these results. It could be down to confounding factors such as socio-economic
factors.
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- "People should not panic. More research must be
carried out to find the mechanism."
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- Dr John Swanson, a scientific adviser to National Grid
Transco and one of the study's co-authors, says: "The study strengthens
the evidence that childhood leukaemia rates are slightly higher near power
lines, but leaves the question of what causes this more confused than before."
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- One theory is that "corona ions", small charged
particles given off by power lines, attach themselves to air pollution
particles. It is argued that those who live nearby are therefore more at
risk from inhaled pollution.
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- Around 400 to 420 new leukaemia cases are diagnosed in
England and Wales each year. Scientists have suggested a range of causes
including genetic susceptibility, ionising radiation, unusual patterns
of exposure to infection and electromagnetic fields.
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- Two major studies published in 2000 by Swedish and American
researchers concluded that there was a doubling of the risk of childhood
leukaemia associated with the level of magnetic field exposure received
around 100 metres from a power line.
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- Alasdair Phillips, of the consumer group Powerwatch,
said: "The Government should bring in a ban on new building within
250 metres of high voltage power lines.
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- "Nurseries and schools, or the adjacent power lines,
should be relocated so that they are further away than 500 metres from
high voltage overhead power lines."
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- © Copyright of Telegraph Group Limited 2005.
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- http://www.telegraph.co.uk/news/main.jhtml?xml=/news
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