European study: Radon gas is responsible for up to 200 deaths a year from lung cancer, with the majority of these deaths occurring in smokers, according to new research from the Radiological Protection Institute of Ireland (RPII).
Passive smokers are also at greater risk, as are former smokers who remain at increased risk for many years after they quit, according to RPII which reviewed a recent Europe-wide survey on the risks of radon gas and lung cancer, with the National Cancer Registry of Ireland (NCRI). It then applied the statistics to Ireland.
Radon is a naturally occurring radioactive gas. It is colourless and odourless and can only be measured using specialised equipment. It can enter buildings through small cracks or holes. When inhaled, the particles can be deposited in the airways and attach themselves to lung tissue. This gives rise to a radon dose which may eventually cause lung cancer.
"Our state of knowledge about the health implications of exposure to radon is evolving all the time," said RPII chief executive Dr Ann McGarry.
The European study examined over 7,000 lung cancer deaths in nine European countries and was the largest "epidemiological investigation ever carried out", on radon in homes, she said.
"It confirms earlier general risk estimates and for the first time gives numerical estimates for radon exposure risks to smokers," she said.
NCRI director Dr Harry Comber said smoking was the most important cause of lung cancer in Ireland but when combined with radon exposure, the risk was even higher. About 92 per cent of the 200-odd deaths from lung cancer per year are smokers, with the remaining 8 per cent in non-smokers who have been exposed to radon.
He cautioned that the 8 per cent figure was an estimate, based on "what we know of the existing risks". "Although radon can cause lung cancer in people who never smoked, the risk is much lower at about one-twenty-fifth of the risk to smokers."
RPII estimates that about 91,000 homes in the Republic have radon concentrations above the national reference level. High radon areas are shown on maps published on the RPII website: www.rpii.i.e.