UK study links pylons and cancer

Children born in homes close to high-voltage power pylons have a 70 per cent higher chance of developing leukaemia, according to a British study.

The study is likely to further fuel bitter opposition to Transpower's controversial proposal for a transmission grid upgrade in the Waikato.

The Oxford University study, published in the British Medical Journal, showed that children who lived within 200m of high-voltage lines at birth had a relative risk of leukaemia of 1.69 per cent - 70 per cent higher than those living 600m or more away.

Children living between 200m and 600m from the lines were 23 per cent more likely to develop the cancer.

No increased risk was found for other childhood cancers.

The study's authors said the evidence, which was based on a survey of 29,000 cases of cancer in children born between 1962 and 1995, showed "an association" between childhood leukaemia and proximity to high-voltage power lines.

However, they said they could find "no accepted biological mechanism" to explain the results.

The relation could be due to the type of people who lived near pylons, the general environment where they are located or even "chance", they cautioned. If a causal link is proven, about 1 per cent of childhood leukaemia in England and Wales could be attributed to power lines. New Zealand scientists say the study opens up more questions than it answers and will further complicate the long-running debate about the link between power pylons and child cancers.

A senior adviser with the National Radiation Laboratory, Martin Gledhill, said scientists had spent the past 20 years focusing on the low-frequency magnetic fields around transmission lines as a possible explanation for higher rates of leukaemia.

However, the results of this study did not fit that theory because magnetic fields would have little or no influence beyond 100m.

Transpower's proposal for a 200km stretch of transmission line from Auckland to the Waikato has provoked an angry response from affected residents, including the burning of an effigy of the company's chief executive, Ralph Craven.

Under the multimillion-dollar plan, pylons up to 70m tall would carry the lines over hundreds of properties, replacing present lines that are 40 to 70 years old and fast falling behind the carrying capacity needed to keep up with growth in the north.

About 300 submissions had been received by the closing date on Friday.

Residents can present their submissions orally at meetings on June 15 and 16, and a decision is expected to be made in mid-July.

- NZPA