Researchers ease fears over radon
Children living in homes with high levels of radon gas or gamma radiation are not at detectably increased risk of developing cancer, according to a major new study published in this week's British Journal of Cancer1.
Worries about the potential dangers to children have been particularly acute in Devon and Cornwall, where radon gas seeps into many homes and the rocks give out high amounts of gamma radiation.
But levels of radon - a naturally occurring radioactive gas - were no higher in the homes of children with cancer than those of healthy children, the study found.
And the amount of gamma radiation in children's homes also seemed to be unrelated to their risk of developing cancer.
Scientists from the UK Childhood Cancer Study, funded by leading cancer charities and a number of other organisations, measured radon and gamma rays in the bedrooms and living rooms of 2,226 children with cancer and 3,773 healthy children.
They carried out detailed statistical analysis, in order to assess whether there was a link between cases of cancer and above average levels of radiation. But the chance of a child developing cancer seemed to be unrelated to increasing radiation levels in the home.
Prof Sir Richard Doll, Chairman of the study group, says: "Previous research has been inconclusive, so it's not surprising that parents have been worried. This study is the first in the UK to measure domestic levels of radiation and relate them to children's cancer risk, and it's pleasing to be able to ease those fears."
Researchers divided childhood cancers into six groups and analysed them separately, to see whether radiation levels might influence some types of cancer but not others. None of the six groupings - which included acute lymphoblastic leukaemia, brain tumours and Hodgkin's disease - showed an increasing trend between levels of radiation and rate of disease. This was true even in areas with high levels of both radon gas and gamma radiation.
Scientists believe that background radiation - which it is impossible to avoid - contributes to some cases of childhood cancer. But the new research suggests that variations in radon and gamma rays from area to area are too small to cause detectable differences in cancer rates.
Prof Doll, who is based at the University of Oxford, adds: "Although some areas have higher levels of radon or gamma radiation than others, the differences don't seem to be big enough to produce a detectable effect. That suggests that background radiation is not playing as large a role as some people have feared."
Dr David Grant, Scientific Director of Leukaemia Research Fund, one of the funding bodies, says: "The first question parents often ask when their child is diagnosed with leukaemia is 'why?' People quite naturally turn to their immediate environment for answers, but it is reassuring to know that commonly encountered levels of radon gas and gamma radiation appear not to put children at risk."
- British Journal of Cancer86 (11)
Note to Editors:
The UKCCS was sponsored and administered by the United Kingdom Co-ordinating Committee on Cancer Research (UKCCCR) and was supported by the UK Children's Cancer Study Group of paediatric oncologists and by the National Radiological Protection Board. Financial support was provided by: Cancer Research UK, Leukaemia Research Fund and Medical Research Council through their grants to their units; Leukaemia Research Fund, Department of Health, member companies of the Electricity Association, Irish Electricity Supply Board, National Grid Company plc and Westlakes Research (Trading) Ltd for general expenses of the study; Kay Kendall Leukaemia Fund for associated laboratory studies' and Foundation of Children with Leukaemia for study of electrical fields. The investigation in Scotland is funded by the Scottish Office, Scottish Power plc, Scottish Hydro-Electric plc and Scottish Nuclear Ltd.