Mr. Aidan O'Connor:

Radon comes under the Radon Protection Institute of Ireland, RPII. On the building regulations side, we insist on the putting in place of a radon barrier. Depending on the area and the location - a map is included in the guidelines - a radon barrier, which is a reinforced membrane that is stronger than the normal damp-proof membrane, goes in under the floor level. Included with it is a sump which can extract air. This would be in the filling underneath and hopefully there would be no pyrite in it. Air can gather in the sump and it is vented. It can then be enhanced with a fan to extract any radon that has built up, if it was drawn to the occupier's attention. That would be done in an area with a high incidence of high radon levels. There is also a retrofit programme in place, mainly led by a local authorities, in fairness to them. They intervene where a problem arises and, effectively, retrofit a radon barrier, a sump and an extractor fan.