Harp Piemonte — Ionising Radiations — Municipal medium radon (ground floor)

A review of the regional map of mean concentrations of radon activity on the ground floor is made available. Radon, a natural radioactive gas, by its nature and its chemical and physical properties easily enters confined environments such as homes, workplaces and schools. It poses a health hazard because it can cause lung cancer. The average radon currently estimated for dwellings in Piedmont is 82 Bq/m³, with a large variation throughout the region.To date, more than 4230 annual concentration measures have been collected in Piedmont in schools and homes, distributed in the Piedmont municipalities. The ever-increasing amount of data allows an ever better characterisation of the regional territory. The average Piedmontese value currently estimated is 82 Bq/m³, significantly higher than reported in previous reports (71 Bq/m³). This could be partly due, in addition to a statistical effect linked to the increase in the size of sampling, also to the energy efficiency of buildings, pursued and implemented almost everywhere in recent years, which reduces the exchange of air in homes and therefore favours the accumulation of radon in confined environments.It should be borne in mind that the current European Directive (2013/59/Euratom) establishes a reference level of 300 Bq/m³, which is exceeded, which is obliged to intervene to reduce concentrations.Also the average data Common per Municipality have in some cases changed significantly compared to the past: in these cases this is due to the change in the basis of calculation, which is now more in line with the actual situation: in fact, the area actually built instead of the entire municipal area was used. The model estimating concentrations follows an approach based on a radiological classification of soil “geolithologies”. Changing the calculation area, now restricted to the actual building alone, has produced an inevitable change in the estimated averages, especially in mountain and foothill areas where the geolithological classification is less uniform. It has been verified that the radon averages thus estimated are now more consistent with the experimental situation.