Pylons and Leukaemia (BBC website)

[Guest guest]

Pylons 'may be a leukaemia risk'

 

The researchers looked at high voltage power lines

Living too close to overhead power lines appears to increase the risk

of childhood leukaemia, researchers say.

A major study found children who had lived within 200m of high

voltage lines at birth had a 70% higher risk of leukaemia than those

600m or more away.

 

But the Oxford University team stressed that there are no accepted

biological reasons for the results and that more research is needed

into such areas.

 

They said it may be down to the type of environments where pylons are

located.

 

People who currently live or have lived near power lines in the

past need not panic about this research

 

Professor John Toy of Cancer Research UK

 

And they said it did not resolve the debate about whether it is

unsafe to live next to power lines.

 

Around 1% of homes in the UK are estimated to be within 200 metres of

high voltage National Grid power lines.

 

The researchers said their findings, published in the British Medical

Journal, showed living in such close proximity to power lines at

birth could account for five extra cases of childhood leukaemia in a

total of around 400 that occur in a year - a total of 1%.

 

The British Medical Journal study did not look at level of exposure

to magnetic fields

 

But other scientists who have considered the issue have suggested

that low frequency magnetic fields, such as those caused by the

production of electricity, could possibly be linked to cancer.

 

However, others have disputed this link.

 

And experts agree that there are likely to be many factors involved

in leukaemia, including genes and the environment.

 

Even if the apparent risk was found to be real, the number of cases

of leukaemia that would result would be very few, said the authors.

 

The study

 

The latest study was carried out by Dr Gerald Draper and colleagues

from the Childhood Cancer Research Group at Oxford University and Dr

John Swanson, a scientific adviser at National Grid Transco.

 

It looked at more than 29,000 children with cancer, including 9,700

with leukaemia, born between 1962 and 1995, and a control group of

healthy youngsters in England and Wales.

 

The researchers measured the distance from children's home addresses

at birth from the nearest high voltage power line.

 

They found that 64 children with leukaemia lived within 200 metres of

the line, while 258 lived between 200-600 metres away.

 

Proposed causes of childhood leukaemia

Genetic susceptibility

Immune system damage by chemicals, infections or radiation before the

baby is born

Abnormal immune system development by lack of exposure to infections

early in a child's life

 

Overall, youngsters living within 200 metres of the lines were about

70% more likely to develop leukaemia, and those living between 200

and 600 metres away about 20% more likely to develop leukaemia than

those who lived beyond 600 metres from high voltage pylons.

 

Although the trend was definite, the researchers said they could not

reasonably explain why it occurred.

 

For this reason, they caution that it might be down to factors other

than the pylons themselves, such as the type of people who live near

pylons or the general environment where pylons are located, which

they plan to investigate.

 

Debate

 

Eddie O'Gorman, chairman of the UK charity Children with Leukaemia,

said: " There is now a clear case for immediate government action.

 

" Planning controls must be introduced to stop houses and schools

being built close to high voltage overhead power lines. "

 

But Professor John Toy, Cancer Research UK's Medical Director,

said: " People who currently live or have lived near power lines in

the past need not panic about this research. The triggers that cause

childhood leukaemia are most likely a random course of events over

which a parent has no control.

 

" This study reports a very slight increase in the risk of childhood

leukaemia for children born near power lines, but the researchers

could not link this to the power lines themselves.

 

" These results may indeed be entirely due to chance. "

 

A spokesman from the Health Protection Agency said the study findings

suggested that at least some of the increased leukaemia risk might be

associated with factors other than electromagnetic fields.

 

Dr David Grant of Leukaemia Research said: " We recognise there is a

lot of public anxiety and concern about living close to pylons and

exposure to power-frequency magnetic fields.

 

" There is no reason why anyone should be advised to move house on the

basis of these new results. "

 

There are around 7,000km of high voltage power lines involved in the

transmission of electricity across England and Wales, and 21,800

steel pylons.