Cancer: a timely warning on radon

ESRI study confirms need for new awareness campaign

The publication of the first study in the Republic to confirm a strong link between living in an area with a high level of radon gas and an increased risk of a lung cancer diagnosis is significant. While it is well established that exposure to the naturally occurring gas is the second most important cause of lung cancer after smoking, the High Radon Areas and Lung Cancer Prevalence in Ireland study quantifies this risk.

Commissioned by the Environmental Protection Agency, the ESRI study links extensive data for more than 5,000 people aged over 50 from the Irish Longitudinal Study on Ageing (Tilda) with data on radon exposure. The Tilda figures allowed other risk factors that could influence an individual's likelihood of a lung cancer diagnosis, such as smoking history, age and gender, to be reliably discounted.

Radon is a radioactive gas that is formed naturally in the ground from the radioactive decay of uranium, which is present in all rocks and soils. It has no smell, colour or taste and can only be detected using radon detectors. Outdoors, radon quickly dilutes to harmless concentrations; however when it enters an enclosed space such as a house it can accumulate to high concentrations. Ireland has relatively high indoor radon concentrations, estimated to be the eighth highest level among OECD countries.

In the region of 250 lung cancers each year in Ireland are linked to radon exposure, with about one tenth of the population in the State at risk from unsafe levels of the gas. The latest research shows that people living in areas where 10-20 per cent of households were above the national reference level for radon exposure (of 200 Bq/m3) were three times more likely to report a lung cancer diagnosis than those who live in areas with fewer than 1 per cent of households above this threshold.


Public health authorities must use this latest data to rejuvenate a national awareness campaign to ensure people in areas of high radon exposure are aware of their risk and know how to mitigate it. And policymakers must consider introducing the mandatory testing of homes prior to rental or sale as well as offering financial incentives to radon-proof buildings.