Pylons' constant radiation factor in cancer danger

A New Zealand pathologist says he is not surprised by a British scientist's warning that children living close to electricity pylons risk developing leukaemia.

Dr Peter Bethwaite, of Wellington, was reacting yesterday to a weekend report on the work of epidemiologist Sir Richard Doll.

Dr Bethwaite said that in the early 1990s, he and Professor Neil Pearce of the Wellington School of Medicine studied occupational exposure to cancer risks.

They found that linesmen and other people exposed to strong electromagnetic fields were more in danger of developing brain cancer and leukaemia than the general population.

They found that farmers and meat workers had the highest risk, not from radiation but from animal viruses, which have a possible association with cancer.

However, Dr Bethwaite said, power station workers, linesmen, appliance repairmen and welders also had high levels of exposure.

"The results were similar to many other studies which showed electromagnetic exposure in adults certainly does increase the risk of cancer and leukaemia."

Dr Bethwaite said power pylons were more of a risk than a television or other appliances because radiation levels were high and constant.

He advised people not to panic, saying childhood cancers were very rare and the increase in risk was small.

However, he said, "I wouldn't advise anyone with children to live within close proximity of power lines."

Meanwhile, an Otago University lecturer, who has researched electromagnetic fields in the home, said the report on Sir Richard's research was unclear.

Dr John Dockerty's 1998 study found no significant link between childhood cancer and electromagnetic fields from household sources and power lines.

"What [the 1998 study] showed us was that for the very large majority of children in our country, at the field levels they were exposed to, there was no risk.

"For a very, very few with a high field there's an indication there could be slight risk."

A real estate expert believes the British study will have no lasting effect on property prices .

A 1995 study from the NZ Institute of Valuers showed that properties within 50m of a high-tension power pylon could lose up to 20 per cent of their value. Property values tended to be affected for up to 100m.

But one of the study's authors, Professor Bob Hargreaves, of Massey University's real estate analysis unit, said he did not expect Sir Richard's report to prompt a major reaction.

"If there's a lot of evidence that pylons really do increase the risk of cancer then I guess people will steer away from those houses," he said.

The only houses to lose value were within 50m of a pylon, so only a small number of homes would be affected.

But Professor Hargreaves said the NZ situation could be worse than those found in the United States and possibly Britain, where corridors separated houses from high-voltage power lines.

He said the study also had to be seen in context.

Previous research on radiation in the home had shown that other items such as televisions and electric blankets were giving out more radiation than was found near high-tension power lines.

Meanwhile, the organisation that oversees New Zealand's radiation standards says science may never know whether extremely low frequency (ELF) fields produced by power lines are safe.

In a booklet on electromagnetic fields and health, the National Radiation Laboratory says that if research on ELF fields shows that they do pose a health risk, it must be considerably lower than that due to asbestos or smoking.

- NZPA