Assessment of Rare Earth Elements, Actinides, and Radionuclides in Nearshore Sediments of Urban-Adjacent Coastal Zones in Athens (Greece) and Fujairah (UAE)

This study presents the first assessment of REEs, actinides (Th and U), and radionuclides in nearshore sediments from Athens, Greece (Kifissos River discharge into the Saronic Gulf) and Fujairah, UAE (harbor area), using XRD, ICP-MS, electron microscopy, and γ-ray spectrometry. REE concentrations were higher in Athens sediments, reflecting geological and anthropogenic influences as revealed by SEM- and TEM-EDS. Thorium in Athens is associated with minerals such as zircon, whereas U in both areas occurred at low crustal background levels. ⁴⁰ K activity varied, while ¹³⁷ Cs activity was higher in Athens and lower in Fujairah, consistent with historical Chernobyl atmospheric deposition.