Tests back power line link to cancer

Claims that overhead power lines are a serious health risk have been supported by research published yesterday.

Claims that overhead power lines are a serious health risk have been supported by research published yesterday.

Scientists at Bristol University have found that people living within 500 metres downwind of high-voltage electricity power lines have a significantly increased risk of developing cancer. If the new findings apply nationally, it would suggest that power lines cause 3,000 premature deaths a year - a similar figure to the annual road accident toll.

The research was carried out for Powerwatch, an independent watchdog group set up to investigate the health effects of power lines. Dr Alan Preece, an epidemiologist atBristol University medical centre, analysed 10,000 cancer cases on the UK South-west Cancer Registry database, separating the addresses of victims by location, in particular by their proximity to power lines carrying 132 kilovolts or more.

The research team found a very significant increase in lung cancers and other cancers linked to pollutants up to 500 metres downwind of power lines, compared with those people living upwind of lines. They also found a high rate of skin cancers close to the lines.

"This is work that is very much in progress and efforts are being made to sort out any possible effects of confounders, such as smoking and social status," Dr Preece said. "Although the statistics look very strong." Emphasising his confidence, he added: "I'm amazed at how robust they appear to be."

The research appears to vindicate a theory developed by Professor Denis Henshaw, of the physics department at Bristol University. He believes power lines ionise the surrounding air, making wind-borne pollution much more dangerous.

"It splits the air up into positive and negative electrical charges, which are blown away from the power line by the wind," he says. "They attach themselves to particles of pollution in the air and put an electrical charge on to them. When you inhale these small particles, they have a much higher probability of sticking in the lung."

A spokesman for the National Grid, the company that operates the power lines, said it was "sympathetic but unconvinced" by Dr Preece's claims. The company's scientific adviser, and spokesman for the UK Electricity Association, Dr John Swanson, said the industry had spent some $500m (£360m) worldwide researching the effects of power lines.