title: Secondary radioactive contamination of the Black Sea after Chernobyl accident: recent levels, pathways and trends.
abstract: The recent radionuclide measurements have showed that concentrations of the Chernobyl-derived (137)Cs and (90)Sr in the surface Black Sea waters are still relatively high, reaching 56 and 32 Bq m(-3), respectively. This is comparable or even exceeds the pre-Chernobyl levels (∼16 Bq (137)Cs and 22 Bq (90)Sr per m(3) as the basin-wide average values). The measurements have revealed that the Black Sea continues to receive Chernobyl radionuclides, particularly (90)Sr, by the runoff from the Dnieper River. An additional source of (90)Sr and (137)Cs was found in the area adjacent to the Kerch Strait that connects the Black Sea and the Sea of Azov. This may be caused by the inflow of the contaminated Dnieper waters, which come to this area through the North-Crimean Canal. The long-term monitoring of (137)Cs and (90)Sr concentration in the Black Sea surface waters and in the benthic brown seaweed Cystoseira sp., in comparison with the earlier published sediment records of the radionuclides, have showed signs of a secondary radioactive contamination, which has started to increase since the late 1990's. This may be the result of the combined effect of a higher input of radionuclides from the rivers in 1995-1999 due to an increased runoff; and a slow transport of the particulate bound radionuclides from the watersheds followed by their desorption in seawater from the riverine suspended matter and remobilization from the sediments adjacent to the river mouths.
authors: The A.O. Kovalevskiy Institute of Biology of the Southern Seas (IBSS), 2, Nakhimov Av., Sevastopol 99011, Autonomous Republic of Crimea, Ukraine. s.gulin@ibss.org.ua
authors: S B
authors: SB
authors: Gulin
authors: N Yu
authors: NY
authors: Mirzoyeva
authors: V N
authors: VN
authors: Egorov
authors: G G
authors: GG
authors: Polikarpov
authors: I G
authors: IG
authors: Sidorov
authors: V Yu
authors: VY
authors: Proskurnin
mesh_terms: D059038:Black Sea; D002588:Cesium Radioisotopes / Q000032:analysis*; D047852:Chernobyl Nuclear Accident; D011834:Radiation Monitoring; D045483:Rivers; D013326:Strontium Radioisotopes / Q000032:analysis*; D014872:Water Movements; D014875:Water Pollutants, Radioactive / Q000032:analysis*; D014881:Water Supply
chemical_list: D002588:Cesium Radioisotopes; D013326:Strontium Radioisotopes; D014875:Water Pollutants, Radioactive
keywords: (137)Cs; (90)Sr; Black sea; Chernobyl; Dnieper