Castleisland in Co Kerry is a radioactive hotspot, according to a new survey published by the Radiological Protection Institute of Ireland (RPII). A large percentage of homes tested there had high levels of the radioactive gas radon.
Published yesterday, the study showed that 52 homes, or 14 per cent of the total sampled, had radon levels above the safety limits set by Government.
Long-term exposure to radon increases the risk of dying from lung cancer to about one in 50, double the risk of dying in a road accident .
Radon is measured in becquerels (Bq) per cubic metre of air, and 200 Bq is the national reference level above which remedial action is recommended to reduce the health risk. Levels in one home in the study reached 6,184 Bq, the third-highest yet found in the Republic, and six of the homes had levels above 1,000 Bq.
The study was prompted after a survey in July 2003 identified a house near Castleisland with a radon level of 49,000 Bq, thought by the RPII to be the highest for a dwelling recorded anywhere in the world. Two people living in the house developed lung cancer, and one has died.
The institute wrote to 2,500 householders in the Castleisland area advising them to have radon measurements, according to the RPII's principal scientific officer, Dr Tony Colgan.
So far 413 householders have requested measurements, and the study published yesterday provides the results available for 377 of these.
The remaining 36 have not yet returned their detectors, according to the institute.
"It is clear from this survey that the potential exists for the accumulation of high radon concentrations in buildings in the areas around Castleisland and the adjacent town of Tralee," said Dr Colgan.
He was not surprised that fewer than one in five households applied for a test, a figure close to the national average.
"I think it is probably an issue of a long-term risk. We are not scared about it," he said. "It certainly isn't a lack of information."
There had been mail shots and a public information meeting in the area. The institute is now mapping high radon homes in the Castleisland area in an attempt to identify any faults in the underlying limestone, something that could help channel the gas up to the surface quickly. The limestone in that area is heavily fissured, according to Dr James McLaughlin, of University College Dublin, who has studied radon levels here since the mid-1980s.
"It is a very porous structure, and there are plenty of underground trapments where the radon is able to accumulate," he said.
The radon in turn seeps up to soil level, to gather at potentially dangerous levels under homes above the limestone. The RPII carried out a national survey of radon in dwellings from 1992 to 1999.
It identified a number of "high-radon areas", areas where more than 10 per cent of homes were predicted to have radon concentrations above 200 Bq.
About a third of the State is now classified as a high-radon area, with known hotspots in Cos Louth, Galway, Wicklow and Kilkenny among others.
The institute advises all householders, particularly those living in high radon areas, to have their homes tested.
Radon is a colourless, odourless gas that arises naturally from the ground due to the gradual radioactive decay of radium in the soil.
