RADIOACTIVITY CONCENTRATION AND DOZE ASSESSMENTS OF PELOIDS FROM SOME TURKISH SPAS

The concentrations of natural radionuclides in peloids from eighteen Turkish spas in different part of Turkey using for therapy treatment and, aesthetic purposes were investigated with the aim of evaluating the radiologic hazard. The concentration of the natural radionuclides (²³⁸U, ²³²Th, ⁴⁰K, ¹³⁷Cs and ²²⁶Ra) were determined by gamma ray spectrometer using HPGe detector. Radium equivalent activity, external and internal hazard index, absorbed dose rate and representative dose rate were calculated and compared with each other and also with the soil or rock results carried out for different parts of Turkey and international approved level values.

The results indicate that high amounts of total thorium and potassium in some peloids (mean 0.02 ppm and 2.0 %, respectively), that this may be sourced from host rocks and their interaction with thermal water. The concentration of ²³⁸U, ²³²Th, ⁴⁰K, ¹³⁷Cs and ²²⁶Ra in the studied peloids ranges from 31.24 to 383.54, 2.62 to 445.36, 64.82 to 1698.60, 0.00 to 5.06, and 55.01 to 425.23 Bq/kg, respectively. These values are higher by a factor of three to six than the world average values of 30, 35, and 400 Bq/kg, for ²³²Th, ²³⁸U, and ⁴⁰K, respectively. The radium equivalent activity in the peloid samples ranges between 116 and 882 Bq/kg. The external hazard indexes (H_ex) of the peloids are range from 0.31 to 2.38 that this values must be equal unity corresponds to the upper limit of Raeq (370 Bq/kg). According to the H_ex, some of the peloids show health risk. The air absorbed dose rate (D) values vary between 35 and 311 nGy/h. The values are higher than the average of the world (60 nGy/h). The average annual effective dose value is 70 μSv/year in open terrestrial area. Determined annual effective dose values ranges from 42.52 to 430.97 μSv/year, with an average of 153 μSv/year are higher than the average of the world. High activity and calculated values in the most of spas may be related to water and/or peloid resources.

Considering the results, radioactivity can also be useful for some diseases, but also create some negative effects. For this reason, detailed and periodic measurements should be made to avoid before happening of health risk and should be prepare cure program for different health problem as soon as possible.