Radioactivity levels and health risks due to radionuclides in the soil and sediment of mid-Black Sea: Kizilirmak Deltas-Turkey

Abstract

Artificial and natural radionuclide pollutants of the marine environment have been recognized as a serious environmental concern. In this study, the activity concentrations of terrestrial and anthropogenic radionuclides in the soil and sediment samples collected from Bafra Kizilirmak Delta were measured by using gamma spectrometry with an NaI (Tl) detector. The average specific of activity concentrations for U-238, Th-232 and 40K were found to be 28.59, 17.48 and 150.59 Bq kg(-1), respectively. On the other hand, Cs-137 was also measured in some samples. Cs-137 (t(1/2)=30.17 years) is a man-made radionuclide released from nuclear fission and activation processes. It has a mean value of 5.32 Bq kg(-1). From the activity concentrations, the radium equivalent activity (Ra-eq), the absorbed gamma dose rates (D-R), the annual gonadal dose equivalent, annual effective dose equivalent, internal (H-in), external hazard index (H-ex) and excess lifetime cancer risk were estimated. This study can be used as a base line for future investigations and the data obtained in this study may be useful for natural radioactivity mapping and also be used as a reference data for monitoring possible radioactivity pollutions in future.