Radionuclide activities and elemental concentrations in sediments from a polluted marine environment (Saronikos Gulf-Greece)

The levels and depth distributions of the natural radionuclides 238 U, 232 Th, 226 Ra, 40 K and the man-made 137 Cs were analyzed by γ-ray spectrometry, while the concentrations of 26 chemical elements were measured by INAA in sediment samples collected from the organic mud layer that covers the Keratsini–Psitalia strait, Saronikos gulf (Greece). The average activity concentration values of 226 Ra, 232 Th and 40 K were lower when compared, whereas that of 238 U was comparable to the average Greek and world values. The elemental contamination of the sediments was estimated on the basis of the calculated EF values. The results revealed high EF values of As, Br, Cr, Ni, Sb, Se, Zn ranging from 160 for Br to 10 for Cr, whose main sources are probable related to contaminated sewage outfall from the area of Athens and the Piraeus Harbour.