New evidence suggesting high voltage power lines may lead to cancer by causing polluting particles to stick to people's lungs has been uncovered by a research team at Bristol University.
The research shows that particles from car exhausts receive an electrical charge from overhead power lines that makes them "sticky" - giving people living close to power lines two or three times the average daily dose of potentially damaging chemicals in their lungs.
Prof David Henshaw of Bristol University claims in today's Guardian that the discovery was the missing link which showed how power lines can cause cancer clusters - the electricity industry worldwide, however, has spent millions researching without finding a conclusive answer.
But a spokesman for the ESB, Mr Michael Kelly, last night dismissed the research as "highly speculative" and said it provided no cause for worry. "His theories have not been approved by other scientists and fly in the face of other research in this area." He added: "The electromagnetic fields to which you and I are exposed in our homes, through items like electric blankets and computers, are far higher than those which we are exposed to through power lines."
The ESB spokesman said no environmental issue had been researched in as much detail as concerns about the links between electricity and cancer. Mr Kelly said no research had proved a conclusive link - the ESB is currently facing opposition to proposals to erect power lines in Cork Harbour, north-west Donegal, west Waterford, Roscommon and Sligo, where health concerns have been raised.
Prof Henshaw's work, however, is supported by Dr Alan Preece at Bristol Medical School, who, in an independent study, showed people living up to 500 metres downwind of power lines have a 29 per cent greater chance of contracting lung cancer. This finding exactly matches the area where "sticky" particulates from car exhausts drift downwind of power cables. Both researchers have said building new houses near power cables, or allowing new power lines near houses should be stopped until their research is fully investigated. A ban exists in US and Sweden because of public concern.
Prof Henshaw said that although the search for a link with cancer had been going on for 20 years scientists have recently been studying a different possible cause: the effects of the magnetic field created by power lines. What his team discovered was not a direct effect on the body, as had been believed, but an indirect mechanical effect which allowed a build-up of pollutants in the lungs.
Measurements taken in the UK and Europe show power lines had a "corona effect". The older the power lines and the rougher the surface of the cable the greater the electrical corona. Positive and negative ions from the corona were carried in clouds downwind of the power lines attaching themselves to the 10,000 to 15,000 particles per cubic metre of pollution already floating past in the atmosphere.
The ions put an electrical charge into the particles of pollution and made them stick to surfaces. When they got down into the small capillaries in the lungs they were attracted to the surface and stuck.
Prof Henshaw said: "This would not happen if power lines were buried. We have the technology to do it, it is just more expensive. But it is a prudent policy."
Dr Preece, an epidemiologist in the oncology department at Bristol, will tell Radio 4's Costing the Earth programme later today he had looked at the incidence of cancer in the south-west of England to judge the relative risk of those living within 400 metres of power lines and for an excess incidence, particularly lung cancer, in people, who had been living within 400 metres of a line at the time of diagnosis.
Dr Preece said the most surprising element was that the cancers only occurred downwind. "Which is interesting, almost if you like, proof or very strong supporting evidence. It is not all people - just those in the footprint of the aerosols driven by the wind."