Working at the Sellafield nuclear plant in Cumbria may have been harmful after all. Children of men who had been exposed to radiation while working at the plant have twice the normal risk of leukaemia and lymphoma, according to a major new study sponsored by the nuclear industry.


LASTING THREAT: children of radiation workers are a t risk (Photo: P Marlow/Magnum)
Arguments have been raging for 12 years over whether radiation from Sellafield is to blame for a local cluster of childhood cancers. The suggestion that there was a link between the doses of radiation received by fathers and the incidence of leukaemia among their children was first made in 1990 by the late Martin Gardner, an epidemiologist from the University of Southampton.

But his hypothesis has since been heavily criticised. Many experts have argued that large numbers of people moving in and out of the area, which is thought to spread infections that might increase the risk of cancer, can explain all the extra leukaemia cases seen around Sellafield.

Now, in the biggest and most comprehensive study to date, scientists from the University of Newcastle have refocused the debate. "Gardner may have been right," says Heather Dickinson from the university's North of England Children's Cancer Research Unit. She and her colleague Louise Parker compared the fates of 9859 children fathered by men exposed to radiation at Sellafield with those of 256,851 children born to other fathers in Cumbria between 1950 and 1991.


Current workforce


Throughout the whole of Cumbria, they found that the incidence of leukaemia and non-Hodgkin's lymphoma was twice as high among the Sellafield children. The incidence was 15 times as great in Seascale, a small village next to the nuclear plant. Crucially, they also discovered that the risk to children rose in line with the radiation dose received by their fathers.

Because a lot of people have moved in and out of Seascale, the researchers found that population mixing did account for most of the extra risk in that village. But for Sellafield children throughout the county, mixing couldn't explain the two-fold increase in risk.

There is growing evidence from human and animal studies that radiation damage can be passed from one generation to the next. But Dickinson and Parker point out that the risks are small: only 13 children of Sellafield workers contracted leukaemia over the 41 years. And because workers now receive much lower doses than in the past, there are unlikely to be implications for the current workforce.

The research was part-funded by the Westlakes Research Institute, which is sponsored by British Nuclear Fuels (BNFL), the state-owned company that runs Sellafield. "This study is very reassuring for our workforce and confirms that the excess risk of leukaemia and non-Hodgkin's lymphoma, particularly in Seascale, can be largely attributed to population mixing," says BNFL's health director Paul Thomas.

But local anti-nuclear campaigners see it differently. "BNFL has tried to discredit Gardner's hypothesis for years," says Janine Allis-Smith from Cumbrians Opposed to a Radioactive Environment. "This study vindicates him and it is irresponsible of BNFL to ignore it."

More at: International Journal of Cancer (vol 99, p 437)


Rob Edwards

New Scientist