The study aims to determine the radioactivity levels of thermal waters which have been used seasonally or permanently in spas for therapeutic intentions. Samples were collected from spas in different regions of Turkey. Some radionuclides (40K, 232Th, 226Ra, 137Cs), gross alpha (GA) and gross beta (GB) activities, and physical and some chemical parameters were measured. Gamma radiation measurements for 226Ra, 232Th and 40K radionuclides were performed by using a high purity germanium (HPGe) detector. The results of the gamma spectrometry ranged from 1.385 to 11.025 Bql−1 for 226Ra, <minimum detectable activity to 3.477 Bql−1 for 232Th and 9.679 to 36.989 Bql−1 for 40K. GA and GB activity concentrations were detected by using ultra-low level α/β counter. The GA and GB activity ranged from 43 to 3,182 mBql−1 and 54 to 1,950 mBql−1, respectively. Based on calculated annual effective dose equivalent, the total dose originated mostly from 226Ra and slightly from 40K. Furthermore, waters with high Cl content were enriched with 40K, 226Ra isotopes, and the source of GA and GB activity in these waters was mostly 226Ra. Strong high positive correlation between Cl, 226Ra and total dissolved solids in Cl-enriched samples indicated that the nuclides formed from dissolved minerals in these waters.
- gamma radiation
- gross alpha and beta
- natural radioactivity
- thermal water
- First received 11 October 2016.
- Accepted in revised form 15 February 2017.
- © IWA Publishing 2017