Activity concentrations of 226Ra, 232Th, 137Cs and 40K in Cystoseira barbata samples harvested from the Eastern Black Sea coast of Türkiye

Macroalgae are important bioorganisms used in fish feed and food industry. In addition, macroalgae are used in studies to determine radioactive pollution levels in the seas. In this study, it was aimed to determine the activity concentrations of 226Ra, 232Th, 137Cs and 40K in Cystoseira barbata which is a brown macroalgae samples obtained from the Eastern Black Sea coast of Turkey. Gamma spectrometry analyzes of the samples were carried out with high purity germanium (HPGe) detector system in the Nuclear Physics laboratory of Recep Tayyip Erdoğan University. The average 226Ra, 232Th, 137Cs and 40K activity concentrations in the samples were found to be 11.2, 7.61, 2.74 and 690.7 Bq.kg-1, respectively. The average annual effective dose values resulting from these radionuclides were obtained as 3.14, 1.75, 0.04 and 4.28 µSv.y-1, respectively. Total annual effective dose values calculated with the contribution of all radionuclides were found to be in the range of 1.37-18.83 µSv.y-1. The calculated annual effective dose values are lower than 0.29 mSv.y-1, which is stated by UNSCEAR as the average annual effective dose received through ingestion of natural radionuclides, and the samples examined do not pose any radiological risk.