Radon and health--an update

The National Radiological Protection Board (NRPB) estimated in 1990 that radon causes 5 per cent of lung cancer in the United Kingdom. The estimate was not based on direct evidence. Since then a number of epidemiological studies have been reported. In addition, various policies have been formulated and some implemented, including the mounting of public campaigns to reduce radon in houses in parts of the United Kingdom.

A review of the scientific literature, policy documents and results of the campaigns has been undertaken.

New data on miners support previous evidence that radon, at the levels found in mines, does cause lung cancer. The one study to add to the two previous case control studies looking at domestic radon tips the scales slightly towards radon being incriminated in homes as well. The effect of smoking, a multiplicative or additive risk with radon, is still unclear. Radon can be calculated to cause up to 383 lung cancer deaths per year in the five currently designated 'radon affected' areas. Approximately 287 of these deaths will be in cigarette smokers, and the most effective way for smokers exposed to radon to reduce their lung cancer risk is to stop smoking.

Evidence of the risk from residential radon is still insufficient to justify the current NRPB advice. If it were, a much more effective radon campaign would be needed. Such a campaign would concentrate on reducing lung cancer in people by tackling both radon exposure and cigarette smoking, rather than simply reducing radon in houses.