Concentrations of Environmental Radioactivity in Sediment Cores from Kulakcayiri Lake

This study was carried out in order to calculate the concentrations of radioactivity in the natural Kulakcayiri Lake of Istanbul (Turkey). Three core samples were taken from Kulakcayiri Lake by drilling and taken from heights of 5-5.5 m, 10-10.5 m and 15-15.5 m at the same point and then moved to the laboratory. According to the laboratory results, the K-40 concentrations of the samples were 325 ± 18 Bq/kg, 353 ± 19 Bq/kg and 367 ± 19 Bq/kg, while their Th-232 concentrations were 38 ± 6 Bq/kg, 43 ± 6 Bq/kg and 42 ± 6 Bq/kg, respectively. Their concentrations of Ra-226 were calculated as 29 ± 5 Bq/kg, 26 ± 5 Bq/kg and 26 ± 5 Bq/kg, while the Cs-137 concentrations of the three samples were calculated as ≤MDA (Minimum Detectable Activity) and existed at very low concentrations. The average activities of K-40, Th-232, Ra-226 and Cs-137 were found to be 348 ± 186 Bq/kg, 41 ± 6.3 Bq/kg, 27 ± 5.1 and ≤MDA, respectively. The results were compared with those of similar studies. These findings and assessments are expected to be an example for future studies and to be of reference quality.