One in every 14 Irish homes has high levels of the cancer-causing gas, radon, the Radiological Protection Institute of Ireland (RPII) has warned.

Radon, a naturally occurring radioactive gas present in all rocks and soils, is classified as a class A carcinogen by the International Agency for Research on Cancer. When it surfaces in the open air, it is quickly diluted to harmless concentrations. However, when it enters an enclosed space, such as a house, it can sometimes build up to high concentrations, leading to an 'unacceptable health risk'.

After smoking, long-term exposure to radon gas in the home is the greatest single cause of lung cancer in Ireland. The gas is linked to around 200 cancer deaths here every year.

According to the RPII, some 250,000 people are currently living in homes with high levels of the gas. However, the vast majority of these are unaware that they are living with such a serious health risk.

"One person every two days dies from a radon induced lung cancer. Over the past decade, up to 2,000 people in this country have died from this preventable health problem. The starting point is for people to test their home for radon and where high levels are found, to reduce those levels. Radon is only a problem if it is ignored," explained RPII chief executive, Dr Ann McGarry.

Testing for radon is easy. It involves two radon detectors being placed in a home - one in a bedroom and one in a living room - for a three-month period. The radon detectors are sent to the home and returned to the service provider by post. The service provider then analyses the results. The cost is around €50.

If radon is detected at a level that requires action, two methods are usually used. If the level of radon is moderate, better indoor ventilation may be all that is required. This is relatively cheap in cost.

If higher levels are found, a fan-assisted sump may be recommended. This can be installed by a contractor in one day. While the cost of the work is around €1,100 and €90 per year thereafter, it reduces the levels of radon gas by more than 90%.

Anyone wishing to see if their address or nearest town is in a high radon area can do so on the RPII's website here. More information is also available on 1800 300 600.