Comparison of Radioactivity and Metal Pollution Concentrations in Marine Sediment Samples Obtained from the Aegean Sea (Turkey) and the Calabria Region (Italy)

Marine sediments are the basic reservoir for radionuclide and metal hold because of their diverse composition. These sediments accumulate naturally occurring radionuclides such as226Ra,232Th, and40K as a result of scavenging and settling processes in the water column. The knowledge of the levels and distributions of the radionuclides such as U, Th, and Ra and heavy metals have common environmental concerns along with the health hazards to human beings, animals as well as the marine environment. This study was to assess the concentrations of some heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) and three main natural radionuclides (226Ra,232Th, and40K) within the surface sediments collected from Turkey (Aegean Sea) and Italy (Calabria region). Activity concentrations of natural radionuclides were measured by High Purity Germanium (HPGe) gamma spectrometry. Heavy metal levels were determined by inductively coupled plasma mass spectrometry (ICP-MS) in Italy and inductively coupled plasma optic emission spectrometry (ICP-OES) in Türkiye. The activity concentrations226Ra,232Th, and40K at Aegean Sea region (Türkiye) ranged from 9± 1 Bq kg−1 dry weight (d.w.) to 60 ± 2 Bq kg−1 (d.w.) for226Ra; from 6 ± 0.3 Bq kg−1(d.w.) to 64 ± 1 Bq kg−1 (d.w.) for232Th; for40K, 250 ± 13 Bq kg−1(d.w.) to 978 ± 6 Bq kg−1 (d.w.) and at Calabria region (Italy) ranged from 14 ± 1 Bq kg−1 dry weight (d.w.) to 54 ± 9 Bq kg−1 (d.w.) for226Ra; from 12 ± 1 Bq kg−1(d.w.) to 83 ± 8 Bq kg−1 (d.w.) for232Th; for40K, 470 ± 20 Bq kg−1(d.w.) to 1000 ± 70 Bq kg−1 (d.w.). The mean concentrations of Mn, Fe, Ni, Cu, Zn, Cr, Cd, and Pb were 197.6; 8139.3; 6.3; 6.0; 24.9; 10.5; 0.05 and 6.8 mg kg-1 (d.w.) in Italy and 187.0; 6993.5; 10.0; 14.3; 29.9; 21.7; 0.02 and 7.1 mg kg-1 (d.w.) in Turkey, respectively. From the measured specific activities, radium equivalent activity, the absorbed dose rate, annual effective dose equivalent, and external hazard index due to the natural radionuclides were calculated to assess the health risk. Radium equivalent activity was lower than the world average for both Turkey and Italy. And also, the external hazard indices were found to be below the hazard limit of unity.