Radon in dwellings in Northern Ireland. Atlas and 1999 review

In May 1999, NRPB published formal advice to Government on radon Affected Areas in Northern Ireland. Estimates of the percentage of homes exceeding the Action Level of 200 Bq m-3 in each 5 km square of the Irish Grid were given in a map covering the whole of Northern Ireland. This companion report gives details of results of radon measurements in homes in Northern Ireland available to early 1999. The data are presented by district council and postcode divisions. They confirm that the majority of homes in Northern Ireland are in areas where indoor radon levels are generally low but that there are some areas, notably in the southeast and northwest, where elevated levels of radon are found in a significant proportion of homes. The atlas section shows the same estimates of the percentage of homes exceeding the Action Level as given in the formal advice to Government in a series of larger-scale maps which also include selected towns and the Irish Grid. (author)