engleski

The natural radioactivity of Istria, Croatia

Because of the geological structure of the Istrian peninsula which mainly consists of limestone that is characterized by karstic topography on its surface, it is expected that there are areas with elevated radon levels in soil gas as well as inside buildings (e.g. houses, kindergartens, schools). Recently, from autumn 2013 until spring 2015, more than 1200 radon measurements at about 500 randomly selected locations (in houses as well as in schools and kindergartens) were performed. The average value of indoor radon in homes is 102 Bq m-3 while the average radon concentrations in kindergartens (181 Bq m-3) and schools (208 Bq m-3) are approximately two times higher than in homes. In fact, in 15.5% of kindergartens and 21% of schools, the average indoor radon concentration is higher than 300 Bq m-3 which is the reference level in Croatia. Radon concentrations in soil gas in the Istrian peninsula were measured from 2013 to 2015 with the AlphaGUARD and RM-2 measuring systems. The obtained average value of 90 kBq/m3 and geogenic radon potential of 74 classifies the soil of Istria County into soil of high geogenic radon potential. It is important to emphasize that there are areas with radon concentrations up to 500 kBq m3. Soil samples were collected according to the standard procedures of the IAEA at 48 different locations. Activity concentrations of selected radionuclides were determined by means of gamma spectrometry by using an ORTEC HPGe detector system. The correlation between radon and its parents radium/uranium were investigated. The linear relationship between GRP and indoor radon per grid cell was found. The influence of climate condition on indoor radon concentration was observed. In accordance with the obtained results, areas with elevated indoor radon levels as well as levels of radon in soil gas were identified and geogenic and indoor radon maps were generated.

indoor radon, geogenic radon potential

Rad je kao poster prezentiran na skupu 10th International Topical Meeting on Industrial Radiation and Radioisotope Measurement (IRRMA X), odtržanom 10.-13.07.2017 g., Chicago, SAD ; objavljen u Book of abstractsm str, 43-44.