Saturday, August 14, 1999 Published at 16:15 GMT 17:15 UK
Child leukaemia linked to infection
There is a glut of leukaemia cases around Sellafield
Childhood leukaemia is likely to be caused by an infection, according to a study by researchers from Newcastle University.
Childhood leukaemia is extremely rare and scientists have been investigating the higher incidence of the disease near sites such as Sellafield nuclear reprocessing plant in Cumbria, northern England, for around 20 years.
The study found in Cumbria that around half of all cases of two childhood cancers - acute lymphoblastic leukaemia (ALL) and the related disease Non-Hodgkin's Lymphona (NHL) - could be linked to an infection caused by outsiders moving into the rural community.
Researchers Heather Dickinson and Louise Parker studied the records of 119,539 children born in Cumbria between 1969 and 1989.
They found that youngsters were much more likely to develop either ALL or NHL if both their parents were born outside Cumbria.
"All children, whether their parents are incomers or locals, are at a higher risk if they are born in an area of high population mixing," Dickinson said in a statement issued by the Cancer Research Campaign, which publishes the British Journal of Cancer.
"But children of incomers seem particularly at risk because they are potentially being exposed to more new infections," she added.
Sir Richard Doll, the renowned cancer expert who first linked tobacco with lung cancer, said childhood leukaemia appeared to be "an unusual result of a common infection".
"You would get an increased risk of it if you suddenly put a lot of people from large towns in a rural area, where you might have people who had not been exposed to the infection," he said.
He added that the study supported a theory developed by Professor Leo Kinlen of Oxford University that childhood leukaemia was caused by infections introduced into a community by migrant workers.
Responding to the findings, Prof Kinlen said the next challenge was "to identify the infective agent, and at the moment scientists have little idea what it could be".