RE: Radon cancer fears dismissed

Radon cancer fears dismissed

List members might be interested to know about the reports detailed below.

It is interesting to speculate to what extent the findings of these reports might influence risk estimates for exposure to ionising radiation or support the theory of that exposures to small amounts of radiation may be beneficial rather than harmful.

BBC Report

http://news.bbc.co.uk/hi/english/health/newsid_2031000/2031084.stm

There is no evidence of a link between radon gas in homes and cancer in children, according to scientists. A major study carried out in the UK found levels of radon gas and gamma radiation were no higher in the homes of children with cancer compared to those who are healthy. There have been fears that high levels of radon gas and gamma radiation in some areas of the country were putting children at risk. Radon gas occurs naturally and is found in many homes in some parts of the country, particularly in Devon and Cornwall. Rocks in these areas also emit high levels of gamma radiation.

Cancer study

Scientists from the UK Childhood Cancer Study, 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. They also divided the children with cancer into six groups, depending on the nature of the disease, to see if radiation levels might influence some types of cancer but not others. However, 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.

Writing in the British Journal of Cancer, the scientists said the findings suggested the risks of children developing cancer did not seem to be related to increasing radiation levels in the home. Professor Sir Richard Doll, chairman of the study group said the findings should reassure parents. "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."

Reassuring

Professor Doll, who is based at the University of Oxford, added: "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 the Leukaemia Research Fund, said: "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."

From the British Journal of Cancer

http://www.nature.com/bjc/

No link between gamma and cosmic rays and childhood cancer

UK Childhood Cancer Study Investigators
This first case-control study directly measuring domestic gamma ray and cosmic ray levels at the homes of UK children with cancer and comparing them with similar data at the homes of control children, has found no indication of increased risk of cancer in general nor of any specific type of malignancy. Higher dose rates did not increase risk and there was no effect in either matched or unmatched analyses, nor with or without adjustment for deprivation. The study also showed no evidence of any interaction between household gamma rays and radon concentrations.

Abstract

This article reports measurements of household levels of gamma and cosmic rays at the addresses of children with cancer at the time of diagnosis and six months before, and of similar data at the addresses of control children. There is no indication of increased risk with increasing dose rates either in matched or unmatched analyses, with or without adjustment for deprivation. Sub-division by diagnostic group did not reveal any association with any specific types of malignancy. Studies of the relationship between household gamma rays and radon concentration show no evidence of any interactions.

British Journal of Cancer (2002) 86, 17271731. doi:10.1038/sj.bjc.6600277

No link between radon gas and childhood cancer

UK Childhood Cancer Study Investigators
The results from this large national study offer no support for the suggestion that radon gas concentration in homes is associated with the incidence of childhood cancer in general, or of leukaemia in particular. Indeed some evidence of decreasing cancer risk with increasing radon concentrations was observed.- a finding that raises interesting questions about the case-control methodology which will be explored further

Abstract

This paper reports the results of the United Kingdom Childhood Cancer Study relating to risks associated with radon concentrations in participants homes at the time of diagnosis of cancer and for at least 6 months before. Results are given for 2226 case and 3773 control homes. No evidence to support an association between higher radon concentrations and risk of any of the childhood cancers was found. Indeed, evidence of decreasing cancer risks with increasing radon concentrations was observed. Adjustment for deprivation score for area of residence made little difference to this trend and similar patterns were evident in all regions and in all diagnostic groups. The study suggests that control houses had more features, such as double glazing and central heating, leading to higher radon levels than case houses. Further, case houses have features more likely to lead to lower radon levels, e.g. living-rooms above ground level. Consequently the casecontrol differences could have arisen because of differences between houses associated with deprivation that are not adequately allowed for by the deprivation score. British Journal of Cancer (2002) 86, 17211726. doi:10.1038/sj.bjc.6600276