BBC News | HEALTH | Pylons safe, says 'definitive' research

BBC News Online: Health

Friday, 3 December, 1999, 01:12 GMT

Pylons safe, says 'definitive' research

A comprehensive survey of childhood cancer has said electrical power lines are not to blame - just a day after separate research suggested exactly the opposite.

The UK Childhood Cancer Survey (UKCSS) is the largest to look at the links between electromagnetic fields of the type generated by power lines and cancers such as leukaemia and Hodgkin's lymphoma.

This major study provides firm evidence that exposure...does not augment risk for childhood cancer
Professor Sir Richard Doll

It found no association between children who fell ill and the strength of electromagnetic fields in their homes.

While the report, published in The Lancet, appears to give the all-clear to the UK electricity industry, its results do not extend to other parts of the world where different methods of electricity supply produce far larger electromagnetic fields.

The study was headed by professor Sir Richard Doll, the scientist who first spotted the link between smoking and lung cancer, and he described it as "definitive".

He said: "This major study provides firm evidence that exposure to the levels of magnetic fields found in the UK does not augment risk for childhood cancer."

The study gathered information on 2,423 children diagnosed with cancer, and compared them with a similar number of healthy children.

The scientists measured the magnetic fields in every child's house, and looked to see if the children who developed cancer were in a more electromagnetically charged environment.

Their figures showed no variation at all between the healthy and cancer children.

In fact, of the 1,000 cancer children they examined in detail, only seven actually lived anywhere near a power line, and none lived within 100m.

Where electromagnetic levels were found to be higher than average, this was usually due to the wiring arrangement of the houses involved rather than power lines.

On Thursday, the University of Bristol's Professor Denis Henshaw published his own research, which suggested that the fields created by power lines increased the amount of airborne cancer-causing pollution which gathered underneath.

Houses shielded from field

Professor Nick Day, from the University of Cambridge, who led part of the UKCCS project, said the Bristol ideas were dubious.

He pointed out that Professor Henshaw's experiments were carried out in the open air, and that houses provided natural "shielding" from the electromagnetic fields.

He said: "Physicists disagree with his theory that the cancer-causing agents can be received within the internal organs."

However, because of a different system of electricity supply in the UK, electromagnetic fields are generally less intense, resulting in only a few children found to be exposed to levels greater than 0.2 micro-Tesla.

In the US and Canada the fields are much stronger, meaning that more children have been exposed routinely to larger amounts of electromagnetism.

A commentary in The Lancet by the World Health Organisation, points this out as a weakness of the study.

Michael Repacholi and Anders Ahlbom of the WHO write: "Although the UKCCS is very large and well-conducted, it is not the definitive study many scientists have been hoping for."

However, the results have been welcomed by the UK electricity industry.

Dr John Swanson, the Electricity Association's scientific advisor, said: "It now seems clearer than ever before that we have to look elsewhere for the real causes of childhood cancer."

Other parts of the UKCCS will be doing just that, using data taken from the same children.

The theories they will be testing include:

A child's exposure to natural or man-made radiation during pregnancy or after birth
Similar exposure to hazardous chemicals
A father's exposure to radiation or chemicals before the child's conception
A child's rare and abnormal response to common infections in the first few years of life

Related to this story:
Battle lines drawn in pylon debate (03 Dec 99 | Health)
Pylons 'treble cancer particles' (02 Dec 99 | Health)
Public gripped by cancer myths (13 Oct 99 | Health)
Leukaemia: Medical notes (29 Oct 99 | Medical notes)
Child leukaemia 'starts in womb' (29 Oct 99 | Health)

Internet Links: The Lancet Leukaemia Research Fund Electricity Association
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