Areas with high radon levels in Italy

A first review of the numerous data on the areas in Italy where high radon concentration in dwellingshave been found is presented here. The data were obtained from the national survey and from severallocal surveys carried out in areas where high radon concentration values were expected, on the basis ofthe national survey results or of geological considerations. The analysis is restricted to data obtainedwith long-term measurements. In the national survey which was carried out in a representativesample of 5361 dwellings from 232 towns 214 dwellings with annual radon concentration over 200Bq/m3 were found in 72 towns, distributed in 17 out of the 21 Italian Regions. The correspondingfigures for 400 Bq/m3 are: 46 dwellings, 25 towns, 6 Regions. Other local surveys were carried out 9Regions, involving almost 3000 dwellings distributed in about 100 towns; the percentage of dwellingswith radon concentration over 400 Bq/m3 ranges from a few percent to about 40% in limited areas.These surveys differ for sampling strategy and detector exposure period, and therefore the resultscannot be easily compared; anyway, only long term measurements have been considered here. In spiteof this limitation, it can be assessed that many areas with high radon concentration have already beenidentified in Italy, also in Regions where the average radon concentration is lower than the nationalaverage. These areas are generally coinciding with those resulted from the survey in schools carriedout in six regions. The data on dwellings collected here and those on schools will be utilized fordefining radon-prone areas in the Italian territory.