Shane Phelan: Even the experts are divided over what effects power lines could have on our health
MEDICAL concerns have moved centre stage in the debate over EirGrid's pylon plans, as the Government has now committed to conducting a fresh investigation into the impact electricity transmission lines have on human health.
A new EU report on the issue failed to find any evidence of a major health threat to humans from high-voltage power lines.
However, the report was far from definitive in its findings.
The debate is set to be stoked even further by a series of public meetings on health concerns organisedby MEPs and local groups.
One such meeting last week heard from Bristol University physicist Professor Denis Henshaw, who was critical of the EU report, saying it omitted well-respected research.
He lists leukaemia, adult brain tumours, Alzheimer's and depression as illnesses associated with living near power lines.
An outspoken figure, his findings have already been seized upon by anti-pylon groups around the country. However, like the EU report, the vast majority of studies have failed to find evidence of significant impact on human health.
Several authoritative studies have been published in recent years on extremely low frequency (ELF) magnetic fields emitted by power lines. They conclude there are no established health consequences from exposure to ELF magnetic fields at the level to be emitted by the type of cables proposed by EirGrid.
The reports include one by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), which sets the guidelines for the strength of magnetic fields emitted by power lines.
Other bodies who reached similar conclusions include the US National Institute for Environmental Health Sciences, the UK's National Radiological Protection Board, the UK Health Protection Agency, the Health Council of the Netherlands, the International Agency for Research on Cancer, and the World Health Organisation.
While magnetic fields can affect the nervous system if there is very high exposure, the ICNIRP guidelines put strict limits on the strength of fields associated with power lines.
The last major report published in Ireland, an expert group report commissioned by the then Department of Communications, Marine and Natural Resources in 2007, said exposure levels which exceed the international guidelines were "highly unlikely to be encountered by the general public".
That report, which involved input from experts from Australia, the Netherlands, Sweden, Italy, the UK and Ireland, also concluded there was limited scientific evidence of a link between ELF magnetic fields and child leukaemia.
The report recommended that "as a precautionary measure future power lines and power installations should be sited away from heavily populated areas to keep exposures to people low".
The evidence, however, was "too weak" to require rerouting existing power lines, it said.
Seven years on, the Irish expert who contributed to that report, UCD professor Dr Anthony Staines, said he still believed the risk was low – but added that it still needed to be taken into consideration.
"It is a small risk, in that childhood leukaemia is rare. An increase in a very small risk is still a small risk. At the same time it is a risk you need to consider," he said. "What I would say to you is that the risks are not zero. The risks are small, but they are not unreal.
"We did some very rough sums for our report. We did not publish the sums in the report because they were too rough, but we reckoned that there might be something of the order of one or two extra cases of childhood leukaemia every 50 years. That is not a negligible risk."