Estimations of Cs activity concentrations using marine parameters issued from MODIS and Copernicus Marine Environment Monitoring Services (CMEMS) data in Souda Bay (Crete, Greece) for the period 2011-2019.

Cesium-137, as the main fission product, is of special interest in the marine environment because of its solubility, which results to very low sinking time. Nevertheless, the conservative form of the main percentage of Cs introduced in the marine environment (70%) makes Cs to be included in the salinity of sea water. Based on this property, in this study, we examine potential relations between Cs activity concentrations and marine parameters issued from Earth Observation (EO) data products in the Southern Aegean Sea, in order to investigate the possibility of Cs to be recorded by satellite data.

Determination and mapping of the spatial distribution of cesium-137 in the terrestrial environment of Greece, over a period of 28 years (1998 to 2015).

In this study, we are applying the GIS techniques in order to record the data that have been collected for cesium-137, over the for the period 1998 to 2015, for the terrestrial environment in Greece. Following the Chernobyl Nuclear Power Plant (CNPP) accident in 1986, extended fieldwork was conducted for the determination of cesium-137 concentrations in the terrestrial environment. In 2011, in the light of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, new campaigns were organized in order to assess the variation in cesium-137 activity concentrations.

Measurement and calculation of radionuclide concentration ratios from soil to grass in semi-natural terrestrial habitats in Greece.

The results of the measurements of radionuclide transfer from soil to vegetation (Poaceae spp.) that conducted during 2010-2014, in free-ranged grazing regions in Greece, are presented in this work. The specific activities of Cs, Ra, Ra and Th radionuclides were measured and the activity concentrations were calculated in samples of soil and grass obtained from several studied regions in Greece.

Radiological risk assessment in the terrestrial ecosystem: comparative study of two software tools used for dose rate calculations.

In this study, two software tools, namely the ERICA Assessment Tool and the RESRAD-BIOTA code, are used for the calculation of the radiological exposure of non-human organisms. For the purposes of the analysis, data retrieved from field studies are used. The site-specific measurements were performed on organisms (mammals-sheep and goats of Bovidae spp.

Calculating the radiological parameters used in non-human biota dose assessment tools using ERICA Tool and site-specific data.

The substantial complexity in ecosystem-radionuclide interactions is difficult to be represented in terms of radiological doses. Thus, radiological dose assessment tools use typical exposure situations for generalized organisms and ecosystems. In the present study, site-specific data and radioactivity measurements of terrestrial organisms (grass and herbivore mammals) and abiotic components (soil) are provided.

Radioactivity measurements and dose rate calculations using ERICA tool in the terrestrial environment of Greece.

In the present study, the radioactivity levels to which terrestrial non-human biota were exposed are examined. Organisms (grass and herbivore mammals) and abiotic components (soil) were collected during the period of 2010 to 2014 from grasslands where sheep and goats were free-range grazing. Natural background radionuclides ((226)Ra, (228)Ra, (228)Th) and artificial radionuclides ((137)Cs, (134)Cs, (131)I) were detected in the collected samples using gamma spectrometry.

Bioaccumulation of the artificial Cs-137 and the natural radionuclides Th-234, Ra-226, and K-40 in the fruit bodies of Basidiomycetes in Greece.

The bioaccumulation of artificial Cs-137 and natural radionuclides Th-234, Ra-226, and K-40 by Basidiomycetes of several species is studied and evaluated in relation to their substratum soils. For this reason, 32 fungal samples, representing 30 species of Basidiomycetes, were collected along with their substratum soil samples, from six selected sampling areas in Greece. The fungal fruit bodies and the soil samples were properly treated and the activity concentrations of the studied radionuclides were measured by gamma spectroscopy.

Global deposition and transport efficiencies of radioactive species with respect to modelling credibility after Fukushima (Japan, 2011).

In this study we conduct a detailed comparison of the modelling response of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident with global and local observations. We use five different model versions characterized by different horizontal and vertical resolutions of the same General Circulation Model (GCM). Transport efficiencies of (137)Cs across the world are presented as an indication of the expected radioactive impact.

Spatial distribution and mobility of organic carbon (POC and DOC) in a coastal Mediterranean environment (Saronikos Gulf, Greece) during 2007-2009 period.

Particulate (POC) and dissolved organic carbon (DOC) is an important parameter for the pollution assessment of coastal marine systems, especially those affected by anthropogenic, domestic, and industrial activities. In the present paper, a similar marine system (Saronikos Gulf) located in the west-central Aegean Sea (eastern Mediterranean Sea) was examined, in terms of the temporal and spatial distribution of organic carbon (POC and DOC), with respect to marine sources and pathways. POC was maximum in winter in the Saronikos Gulf, due to the bloom of phytoplankton, whereas in the Elefsis Bay (located in the north side of the Saronikos Gulf) in summer, since phytoplankton grazes in the Bay in the end of summer (except for winter).

Evaluation of processes occurring in the bottom nepheloid layer (BNL) of an eastern Mediterranean area using 234Th/238U disequilibria.

Particle-reactive radionuclide (234)Th and its ratios with the conservative (238)U were used to trace the marine processes occurring over short timescales in the bottom nepheloid layer (BNL) of seven stations in the Saronikos Gulf and the Elefsis Bay (Greece) during three seasons (summer 2008, autumn 2008 and winter 2009). Summer was considered as a steady season where low physical processes occur and stratification is well established, autumn as a commutative period and winter as period of extensive trawling and physical activities. The obtained ratio profiles showed excess of (234)Th relative to (238)U in the BNL of the sampling area during summer, caused by the dissolved fraction of (234)Th.

The dispersion of 137Cs in a shallow Mediterranean embayment (Saronikos Gulf--Elefsis Bay), estimated inventories and residence times.

The activity concentrations of (137)Cs in the water column of the Saronikos Gulf and Elefsis Bay (Greece) determined during four cruises between winter 2007 and winter 2009 are evaluated in the present study. The activity concentrations of (137)Cs ranged between 1.0 ± 0.

Distribution of low-level natural radioactivity in a populated marine region of the Eastern Mediterranean Sea.

The levels of natural radioactivity have been evaluated in the water column of an eastern Mediterranean region (Saronikos Gulf), with respect to the relevant environmental parameters. A novel methodology was used for the determination of natural radionuclides, which substitutes the time-consuming radiochemical analysis, based on an in situ sample preconcentration using ion-selective manganese fibres placed on pumping systems. With regard to the results obtained, (238)U-series radionuclides were found at the same level or lower than those observed previously in Mediterranean regions indicating the absence of technologically enhanced naturally occurring radioactive material (TENORM) activities in the area.

Radioactive pollution in Athens, Greece due to the Fukushima nuclear accident.

As a result of the nuclear accident in Fukushima Dai-ichi power plant, which started on March 11, 2011, radioactive pollutants were transferred by air masses to various regions of the Northern hemisphere, including Europe. Very low concentrations of (131)I, (137)Cs and (134)Cs in airborne particulate matter were measured in Athens, Greece during the period of March 24 to April 28, 2011. The maximum air concentration of (131)I was measured on April 6, 2011 and equaled 490 ± 35 μBq m(-3).

Distribution of natural radioactivity in sediment cores from Amvrakikos Gulf (Western Greece) as a part of IAEA's campaign in the Adriatic and Ionian Seas.

The vertical distribution of natural radionuclides ((232)Th decay, (238)U decay, (40)K and (210)Pb) was assessed in sediment cores collected from the Amvrakikos Gulf, (Ionian Sea, Western Greece). Two collection stations were selected, the first at the western part of the Gulf near Preveza Strait (13A station) and the other near the centre of the Gulf (13B station). Activity concentrations were measured by means of gamma-ray spectrometry using high-purity germanium (HPGe) detectors installed at two national laboratories.

Estimation of dose rates to humans exposed to elevated natural radioactivity through different pathways in the island of Ikaria, Greece.

A radiological survey has been carried out in the island of Ikaria based on the natural radionuclide inventory in abiotic environment and the consequent dose rate assessment for the critical groups of population. The island of Ikaria-Aegean Sea, Greece is characterised by the presence of mineral and thermo-mineral springs, which have an apparent influence on natural background radiation of the island. The levels of natural radionuclides in spring water (either for spa treatment and household use), potable water (local domestic network), and rock and soil samples were measured in this island.

The concentration of 137Cs in the surface of the Greek marine environment.

The radiological status of the Greek marine environment, prior to the Chernobyl accident, was characterized mainly by the fallout from nuclear weapon tests. However, the release of radioactivity into the environment from the accident in the Chernobyl Nuclear Power Plant and its deposition in the Greek marine environment resulted in an increase of the (137)Cs activity concentration by approximately one order of magnitude. In addition, the direct transport of radiocaesium into the North Aegean Sea has been further influenced by the late impact of the Chernobyl accident on the Greek marine environment, related to the transfer of (137)Cs, mainly through the Dnieper but also the Danube rivers, to the Black Sea and further to the North Aegean Sea through the Straits of Dardanelles.

Temporal and spatial distribution of 137Cs in Eastern Mediterranean Sea. Horizontal and vertical dispersion in two regions.

Caesium-137 activity concentration in the water columns of the Gulf of Patras (Central Greece) and the North-Eastern Aegean Sea (easterward to Lemnos Island) was investigated in selected sampling stations during the period September 2004-June 2006. The methodology followed was based on the sorption of caesium (Cs) on cotton wound cartridge filters impregnated by Cu(2)[Fe(CN)(6)] via in-situ pumping. In terms of the horizontal and vertical records, the activity concentrations of (137)Cs in the Gulf of Patras ranged between 1.

(137)Cs baseline levels in the Mediterranean and Black Sea: a cross-basin survey of the CIESM Mediterranean Mussel Watch programme.

The common mussel Mytilus galloprovincialis was selected as unique biomonitor species to implement a regional monitoring programme, the CIESM Mediterranean Mussel Watch (MMW), in the Mediterranean and Black Seas. As of today, and upon standardization of the methodological approach, the MMW Network has been able to quantify (137)Cs levels in mussels from 60 coastal stations and to produce the first distribution map of this artificial radionuclide at the scale of the entire Mediterranean and Black Seas. While measured (137)Cs levels were found to be very low (usually < 1 Bq kg(-1) wet wt) (137)Cs activity concentrations in the Black Sea and North Aegean Sea were up to two orders of magnitude higher than those in the western Mediterranean Basin.

An assessment of the external radiological impact in areas of Greece with elevated natural radioactivity.

In the present study, the radiological impact assessment in three selected areas of elevated natural radioactivity in Greece is attempted, based on measurements, theoretical relations, and simple model application. These areas are Milos--an island of volcanic origin in Cyclades Archipelago, Ikaria--an island in the Eastern Aegean Sea and Loutraki--a coastal area in mainland Greece. These areas are characterized by their geothermal springs and vents, which emit fluids into the littoral and sublittoral zones.

Study on the behavior of the heavy metals Cu, Cr, Ni, Zn, Fe, Mn and 137Cs in an estuarine ecosystem using Mytilus galloprovincialis as a bioindicator species: the case of Thermaikos gulf, Greece.

Mussels are worldwide recognized as pollution bioindicators and used in Mussel Watch programs, because they accumulate pollutants in their tissues at elevated levels in relation to pollutant biological availability in the marine environment. The present study deals with the use of Mytilus galloprovincialis as a local bioindicator of heavy metal and (137)Cs contamination in an estuarine ecosystem (Thermaikos gulf, Greece in Eastern Mediterranean). M.

Field observations of the effects of protracted low levels of ionizing radiation on natural aquatic population by using a cytogenetic tool.

In the present study, an effort is attempted to record the impact of chronic radiation on natural aquatic populations exposed to protracted doses (lower if compared to intervention levels but higher if compared to typical background) and to chemical pollution. The methodology is based on the analyses of chromosome aberrations observed in cells. Therefore, some preliminary research results on the cytogenetic effects on aquatic organisms of various taxa, in coastal ecosystems are presented, considering some selective regions of elevated natural gamma radiation and conventional pollution.

Radiological impact in Greece of the Chernobyl accident--a 10-y retrospective synopsis.

The present study summarizes the published results of the studies of the Environmental Radioactivity Laboratory on the radiological impact in Greece of the Chernobyl nuclear accident. Some unpublished data from personal communications also have been used to present the time evolution of the studies. The radiological impact in Greece of the Chernobyl accident is examined in two separate phases: that of the acute effects and that of the delayed effects.

Strontium-90 activity in monthly milk samples from Greece.

The present study evaluated after the Chernobyl nuclear accident the activity of 90Sr in commercial bovine milk sampled monthly from 1987 to 1994. Monthly mean activities (0.04 to 1.