A secret British report has raised fresh fears of a link between power lines and cancer.
The confidential study urges government officials in Britain to consider banning the building of homes and schools close to overhead high-voltage power cables because of possible health risks.
It says a ban is the best way to reduce significantly exposure to electromagnetic fields from the electricity grid system.
The report was drawn up by scientists, electricity company bosses, the British National Grid, government officials and campaigners over two years after the Health Protection Agency accepted there was a weak statistical "association" between prolonged exposure to power fields and childhood leukemia.
But the 40 members of the panel have clashed over the final details and conclusions.
In the USA, there has been suggestions that such childhood illnesses as leukemia and brain cancer might be linked to power lines where communities with a higher than average rate of sickness were located near power lines and transformer stations. Also, amateur radio operators have known that they have an increased risk for leukemia, thought to be associated with exposure to electro-magnetic waves.
The British secret report stops short of specifically recommending a ban on new homes and schools within 60 metres of power lines, or vice versa, which could wipe a total of 4 billion dollars worth off property prices across Britain and limit land for housing developments.
But the report concludes that the British Government should consider such a move, stating: "We urge government to make a clear decision on whether to implement this option or not."
The report, to be signed off by panel members next week, has sparked conflict at a series of hearings, according to a Whitehall source.
Two members of the panel, regulator Ofgem and Scottish & Southern Energy, are understood to have quit.
Some members of the panel took the view - adopted by the Government's health advisers and the World Health Organisation (WHO) - that childhood leukemia is the only adverse health effect where evidence is strong enough for precautionary measures to be considered.
According to this view, if there is a link, the building ban would cut just one case of childhood leukemia every year or two and the costs would outweigh the benefits by a factor of at least 20.
The second group generally backed views highlighted by the California Department of Health Services which suggested electromagnetic fields are "possibly carcinogenic" in terms of childhood leukemia and placed four other health effects in this risk category. They were adult leukemia, adult brain tumours, miscarriages and a form of motor neurone disease, although some scientists believe there are links with more diseases.
"The advice to government from following this 'California' view would therefore be to tend to favour implementing the 'corridors for new build' option," (safe zones well away from power lines) SAGE added, stressing that in this scenario the costs and benefits would be at least comparable.
The panel is set to recommend that the Health Protection Agency should issue more information about how to reduce the impact of exposure to electromagnetic fields. It will also call for a change to the working of overhead lines to reduce the radius of intense electromagnetic fields.
This study and many more replicated in America could shed light on the cause of various cancer "clusters" in certain communities located near power lines and could prompt legislation in the future.