Power line-leukemia link
Britain’s National Radiation Protection Board has officially recognised the link between exposure to EMR from power sources and childhood leukemia. What did the report find? What has been the reaction - and what are the implications for Australians?
Decades after establishing a connection between smoking and lung cancer, eminent UK epidemiologist, Sir Richard Doll, has found evidence that extremely low electromagnetic fields from the power system are associated with an increase in child leukemia.
The report, prepared by a committee chaired by Doll for Britain’s National Radiation Protection Board (NRPB), re-examined the data of nine previous epidemiological studies of 3247 leukemia victims. It concluded, “Taken in conjunction they suggest that relatively heavy average exposures of 0.4 µT [4 milliGauss(mG)] or more are associated with a doubling of the risk of leukaemia in children under 15 years of age.” While the report adds that the evidence “is not conclusive”, it continues, “Nevertheless, the possibility remains that high and prolonged time-weighted average exposure to power frequency magnetic fields can increase the risk of leukaemia in children.” This is the first official recognition of the health risk from power sources.
The findings are consistent with a number of other studies. Studies which have found an increased risk of leukemia from exposure to power sources include those by Feychting (>1mG), Green (>1.4 mG), Greenland (>2mG), Michaelis (>2mG), Linet (>3mG), Savitz >2mG) and Ahlbom (doubled risk at >4mG). Further, a German study by Schüz released in the same week as the Doll report, found an increased risk of childhood leukemia at overnight exposures of 2 mG and above.
These exposures are minute compared to those allowed by existing guidelines in Australia. At present the NHMRC’s Interim guidelines on limits of exposure to 50/60 Hz electric and magnetic fields allows people to be exposed to 1000 mG at home and 5000 mG at work. These guidelines, originally devised to protect against the induction of current in the tissues of the central nervous system, are now clearly inadequate for protecting public health.
Along with a flurry of media attention, the Doll report has generated an interesting variety of reactions. Australia’s peak electric authority, the ESAA, says that the report “does not conclude that there is a cause and effect relationship between any level of EMF exposure and cancer” and points out that the NRPB “does not recommend any changes to existing EMF guidelines.”
However, Health Minister Dr Michael Wooldridge adopted a more cautious approach. He “warned families living close to high-voltage powerlines to keep very young children away from the potentially cancer-causing electromagnetic radiation.” (SMH 07.03.01)
EMRAA issued a press release which stated that “the present guidelines do not adequately protect people’s health” and called for the Federal Government to develop new guidelines and to site high voltage powerlines away from residences. (07.03.01)
Dr John Loy, CEO of the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) said, “there is no formal exposure standard and the current health guidelines for exposure to ELF fields were released in 1989 … the rationale for the exposure levels is dated. I will ask to RHC [Radiation Health Committee] to place review of the interim guidelines and the need for an exposure standard on its agenda for early action. The issue of how such a standard might deal with precautionary approaches to limiting exposures of children clearly will be important.” (15.03.01)
EMRAA News June 2001, Vol 6 No 2