A HOUSE in Tralee, Co Kerry, has recorded levels of the radioactive gas radon at almost 70 times the recommended level.
Those living in the house receive a radiation dose equal to 47 chest X-rays each day, according to figures released by the Radiological Protection Institute of Ireland (RPII).
Radon occurs naturally, but still ranks as a class-1 carcinogen.
The odourless, colourless gas which increases the risk of lung cancer in smokers and in non-smokers has in recent years been linked to cases of lung cancer in the Castleisland to Tralee area. Persistent high radon levels in the region have led to appeals to householders to measure for the gas.
Radon levels are measured in becquerels (bq) and the maximum limit in homes set by the RPII stands at 200bq.
One Tralee home had levels of 13,797bq and another reached 8,490bq.
These are among the highest ever recorded in Europe, the RPII said in a statement yesterday, and rank as the third and fourth highest yet found here.
The towns of Tralee and Castleisland now have 15 of the top 20 highest measurements found by the RPII. In part this relates to the karstic limestone terrain in the region, but this is not the only type of geology which leads to radon gas seepage.
Surveys by the institute have shown there are also high measurements in Sligo, Mayo, Clare and Tipperary.
To date the RPII has measured 36,700 homes in the country. It has urged residents in other areas to measure for the gas.
There are legal requirements for businesses to measure for radon, and some have been prosecuted by the RPII in the Tralee area for not taking measurements.
Radon gas is increasingly being recognised as a workplace risk factor, and the Health and Safety Authority is also carrying out inspections, said David Fenton of the RPII yesterday.
He said he was surprised at the relatively low level of take-up of radon measuring devices in north Kerry to date. “It is surprising that in areas like Tralee and Castleisland there isn’t more of a take-up of measurement.”
Measuring is a relatively simple process, and more information is available at the RPII website www.rpii.ie where people can search for their address on an interactive radon map to see whether their home or workplace is in an area predicted to have high radon levels.
Information can also be obtained on freefone 1800 300 600.
Nationally, radon is the second highest cause of lung cancer after smoking, and is directly linked to about 200 lung cancer deaths each year.
Measuring for radon and, in the event of a high reading, reducing the levels present are both relatively inexpensive.
The cost of a measurement, which occurs over a three-month period, is between €40 and €80.
All new homes built since July 1st, 1998, must be fitted with a standby radon sump which can be activated later to reduce any high radon concentrations subsequently found.
For homes built in high-radon areas, the installation of a radon barrier as well as a standby radon sump is required.
The radiological protection institute will hold a public meeting in Tralee on Thursday, October 22nd, in the Meadowlands Hotel at 7.30pm to address the dangers of radon and what can be done to reduce the risk.
Hidden danger: risk of cancer
Radon levels in the two Tralee homes were shockingly high, thereby putting their occupants at greatly increased risk of lung cancer.
Ironically, an identical house down the street or even next door would likely give a completely different radon reading.
Many factors influence the build-up of radon in a given home.
Chief among these is whether the house stands in an area known to produce high levels of radon.
These have been found in Kerry, Louth, Clare and Galway among other areas.
The gas forms when trace amounts of uranium in rocks and soil decays. The resultant radon percolates to the surface and in open space simply blows away on the wind.
House foundations block the radon, allowing it to seep into gaps or subfloor spaces where it can accumulate.
If these spaces are ventilated the radon harmlessly dissipates but in some homes, it builds up and may slowly move into living areas where it will deliver a radiation dose.
The radon itself does not cause the damage. Some radon will break down further, producing "daughter" particles. If this breakdown occurs when the radon is breathed in, the radiation exposure is delivered by the daughter particles.
Modern homes typically include a radon barrier at foundation level, nothing more than a layer of heavy plastic sheeting that totally stops the radon.
Even high radon homes can be made safe by improving subfloor ventilation, often done by mounting a small extractor fan to carry away the gas.
DICK AHLSTROM