CAMPAIGNERS against a massive line of power pylons in the Vale of York said research released today suggesting a link between electricity lines and childhood leukaemia added weight to their arguments.

Researchers estimated that youngsters living within 200 metres of lines were about 70 per cent more likely to develop leukaemia, compared with those who lived beyond 600 metres.

But they said they could not show power lines were the cause of increased risk, and admitted their findings could be due to chance.

Professor Mike O'Carroll, chairman of pressure group REVOLT (Rural England Versus Overhead Line Transmission), welcomed the findings.

He said: "It's getting more and more difficult for authorities to deny that power lines are not a causal factor in childhood leukaemia.

"Importantly, it's a different kind of study. It's to do with exposure during pregnancy, whereas all other results were to do with exposure just before diagnosis."

Members of the campaign group spent more than a decade opposing plans to build a 50-mile high-power link between Teesside and Shipton-by-Beningbrough, on the outskirts of York.

Pensioner Rosalind Craven fought a "David and Goliath" battle with power company National Grid to stop them building three pylons on her land at Home Farm, Huby.

Vale of York MP Anne McIntosh has since launched a campaign to highlight the risks.

She has pledged to oppose the building of any more overhead lines in her constituency or any other part of North Yorkshire.

Some researchers have suggested that low frequency magnetic fields, such as those caused by the transmission of electricity, could possibly be linked to cancer.

The latest study, published in the British Medical Journal, looked at more than 29,000 children with cancer, including 9,700 with leukaemia, born between 1962 and 1995.

Dr Gerald Draper 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.

Speaking on behalf of National Grid, Dr John Swanson, scientific adviser to the Energy Networks Association, admitted the study strengthened evidence that childhood leukaemia rates were slightly higher near power lines.

He said: "But it leaves the question of what causes this more confused than before.

"It may not be the field produced by the power line, but some characteristic of the areas power lines pass through."

He added: "In the meantime, we have already recognised the need to consider whether there should be any changes to the safety limits that relate to power lines or to planning controls near power lines.

"That is why we have already taken the initiative to start discussions with Government, regulators, professional bodies and interest groups about exactly these issues."

Updated: 10:37 Friday, June 03, 2005