Scientists at Bristol University have evidence that overhead power lines can attract and concentrate radioactive particles formed from radon, a naturally occurring radioactive gas and known carcinogen.
They argue that this effect may cause more radioactive particles to be inhaled which stick to the mouth, throat and lungs, from where they are absorbed into the blood, delivering an increased radiation dose to sensitive tissues such as the bone marrow and the foetus. The research published today in the International Journal of Radiation Biology is the foundation for the first, plausible, explanation of a biological mechanism by which electromagnetic fields (EMFs) generated by overhead power lines could influence the development of cancer. Critics of the cancer/ power lines hypothesis havepointed to the lack of such an explanation as a serious flaw.
The link with childhood cancer was first identified in the United States almost 20 years ago. Subsequent international studies supported the initial findings particularly with regard to leukaemia, and there were several reports from around Britain of children with cancer who lived near or under power lines.
In Abergavenny, Gwent, there have been six cases of brain or spinal tumours on one small estate on the edge of the town which is criss-crossed by power-lines. Two children living there have had brain tumours while the number of children under 15 who contract brain tumours each year nationally is less than 350.
One mother, Jill Davies, hopes this latest research will help her legal battle against South Wales Electricity Company, to highlight the case of her 17-year-old son, Noel - a once-promising rugby player at county level - who suffers from a brain tumour first diagnosed at Christmas 1993.
In one street in Northampton there have been three cases of leukaemia (there are about 600 cases nationally each year). The main London to Scotland railway line, with electrified lines, runs alongside the street. In 1993, a review by the National Radiological Protection Board in the United Kingdom concluded that there was some evidence from Scandinavian countries of a link between leukaemia and EMFs.
But Sir Richard Doll, the eminent cancer epidemiologist who chaired the NRPB group, again pointed to the lack of explanation of a causal link.
Professor Denis Henshaw, leader of the Medical Research Council team at Bristol, and an expert on radon, said the new findings open up a whole new area of investigation.
The Electricity Association dismissed the Bristol team's claims as "unsubstantiated". "No research to date has provided an effective basis for recommending restrictions on EMF exposures," a spokesman said.