Radioactivity levels in mussels and sediments of the Golden Horn by the Bosphorus Strait, Marmara Sea

The Golden Horn is an estuary located in the center of İstanbul receiving freshwater discharges from two creeks and connecting to the Bosphorus Strait. Activity concentrations of natural and artificial radionuclides were determined in mussels (Mytilus galloprovincialis) and sediments from the Golden Horn sampled in February 2012. Mean activity concentrations of 137Cs, 40K, 226Ra, 228Ra, 210Po and 210Pb in the mussels were determined at 1.03 ± 0.23, 389 ± 41.6, 2.61 ± 1.23, not detected (ND), 91.96 ± 37.88 and 11.48 ± 4.85 Bq kg−1, respectively. In sediments, it was observed that 137Cs, 40K, 226Ra, 228Ra, 210Po and 210Pb activity concentrations in <63 μm particle fraction of sediment were generally higher than those determined in mussels. Po-210 and 210Po/210Pb ratios in mussels from the Golden Horn were much lower than in mussels from other coastal regions and this was related to low plankton productivity and eutrophication of the Golden Horn.