engleski

The radon levels in Istrian peninsula

Long-term indoor radon measurements performed by LR-115 track etched detectors in Croatian homes during 2003/2004 showed the arithmetic means of radon concentrations in Istria County were slightly higher (76 Bq/m3) than in houses at national levels (68 Bq/m3) [1]. The detectors were randomly distributed depending on population density and many of these detectors were exposed in houses in the cities at the coast. Because of the geological structure of Istian peninsula which mainly consists of a 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 above (e.g. houses, kindergartens, schools). Recently, from the autumn of 2013 until the spring of 2015, the radon measurements at more than 1000 randomly selected locations (in houses as well as in schools and kindergartens) were investigated. The obtained results will be presented and discussed. Radon concentrations in soil gas in Istrian peninsula were measured in November of 2013 and 2014 and February of 2014 and 2015 with the AlphaGUARD and RM-2 measuring systems. The obtained average value of 103 kBq/m3 classifies the soil of Istria County, according to the used soil classification [2], into soil of high geogenic radon potential. It is important to emphasize that there are area with radon concentrations up to 500 kBq m3. In accordance with the obtained results the areas with elevated indoor radon levels as well as levels of radon in soil gas were identified and radon maps were generated using different geostatistical approaches. Radon concentrations in the municipal water supply systems were also measured with AlphaGUARD system using procedure for quick determination of radon values. The highest measured value was 5.6 Bq/l and is much lower than the usual reference level of 100 Bq/l.

Indoor radon ; Radon in soil gas ; Radon mapping

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