engleski

The influence of geological formations on geogenic radon potential and/or indoor radon Croatia

In the last few years, the targeted surveys of indoor radon in homes as well as in public buildings with high occupancy (kindergartens and schools) were performed in several counties in Croatia with different geological formations. In the southern part of Croatia, geological structure mainly consists of a limestone plateau and dolomites formed in the Jurassic and Late Cretaceous while carbonate rocks, especially flysch, during Paleogene period. The northern part consists geologically mainly of sandstones and soft clay formed during the Neogene and Quaternary periods. Sediments are of gravels, loess and silts and are all the products of mostly continental environments and alluvial fans. Differences in geological structures of these two areas inevitable suppose to have, as a consequence, very different geogenic radon potential (GRP). Indoor radon was measured by track etched detectors which were randomly distributed in homes, schools and kindergartens across the whole geographic areas and the number of detectors dependend on population densities of the investigated areas. Radon concentrations in soil gas in Croatia were measured with the AlphaGUARD and RM-2 measuring systems while soil permeability was measured by Radon-JOK permeameter. A detailed GRP map based on in-field soil gas radon and soil gas permeability measurements was carried out using “Neznal’s” approach. The relationship between geological formations and GRPs or indoor radon were examined. According to the obtained results, the criteria for identification of “radon prone area”, as part of the future National Action Plan, for radon is proposed and discussed.

geological structures ; radon concentration ; soil permeability

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