Time variability of radon activity concentration in waters of Povazsky Inovec

Radon concentration in waters is not constant and can exhibit a significant variability in longer time horizon. In this contribution, we deal with long-term monitoring of changes in radon activity concentration (RAC) in five selected springs of Povazsky Inovec Mountains, depending on meteorological conditions affecting their temperature and yield, and also the type of subsoil. First sampling of water was carried out in March 2015, although methodical monitoring of RAC took place during two years since September 2015. Waters of these springs contain greater concentration of ²²²Rn and were situated on the subsoil with larger content of ²²⁶Ra in the rocks. A negative correlation was observed between spring temperature and RAC; in contrast, a positive correlation was found between spring yield and RAC in waters. Higher values of RAC during the monitoring period were found in winter months and even in early spring. The highest value of RAC was measured in Dastinska kyselka spring (with the average of 201 Bq/l) with RAC ranging from 176 to 225 Bq/l. (authors)