Biokinetics of radiocesium in shrimp (Palaemon adspersus): seawater and food exposures.

The bioaccumulation of (134)Cs was studied in the shrimp Palaemon adspersus (Rathke, 1837) using dissolved or food pathways. The uptake and loss kinetics (following seawater and food uptake) were followed for 27 and 38 days, respectively. The steady state concentration factor (CFss) value of (134)Cs in the whole body of the shrimp was found to be 15 ± 0.08. The loss kinetics of radiocesium was described by a two-component exponential model, with a biological half-life of 85.5 days for the whole body. The depuration kinetics of (134)Cs was best fitted to a single-component exponential model for both edible and inedible parts. The depuration kinetics of (134)Cs following exposure via pulse-chase feeding was also described by a two-component exponential model, with a biological half-life of 84.2 days. Assimilation efficiency (AE) was found to be 38.5%. Most of the radioactivity was accumulated in muscular tissues (the edible part) of the shrimp compared to the remaining soft parts. The average of the total body burden of (134)Cs eliminated with molting was %15.3 ± 8.1.

Radioactivity concentrations in mussel (Mytilus galloprovincialis) of Turkish Sea coast and contribution of ²¹°Po to the radiation dose.

Radionuclides levels were determined in indigenous and transplanted mussels (Mytilus galloprovincialis) collected from Turkish marine environment. Radioactivity concentrations of ¹³7Cs, 4°K, ²²6Ra, ²²8Ra, ²¹°Po and ²¹°Pb were determined in the soft tissues of the mussel samples collected in Bosphorus Strait, Coasts of Black Sea, Marmara Sea and Aegean Sea. Mussel transplantation was carried out by using mussel cages in Levantine Sea coast since M. galloprovincialis did not naturally adapt along the coast. The average activity concentrations of ¹³7Cs, 4°K, ²²6Ra, ²²8Ra, ²¹°Po and ²¹°Pb in the coastline of Turkey were found to be 0.7±0.1, 469±24, 0.9±0.1, 1.0±0.1, 122±4 and 10.9±0.9 Bq kg⁻¹ in dry weight (dw), respectively. The average of ²¹°Po/²¹°Pb ratio was found to be ∼14. Total annual effective ²¹°Po dose was calculated to be in the range of 0.25-3.30 µSv due to mussel consumption. Radioactivity and dose levels were compared with those of similar studies carried out in Mediterranean countries.

Natural and artificial radionuclide activity concentrations in surface sediments of Izmit Bay, Turkey.

Surface sediments from the north-eastern coast of the Marmara Sea, Turkey's most industrialized coastal region, were enriched with radioisotopes from the Chernobyl explosion in 1986. Caesium-137 in these sediments is also thought to originate from one former paper mill located nearby that used wood contaminated by Chernobyl explosion-originated (137)Cs for paper production. The average activity concentration of the (137)Cs was 21 Bq kg(-1), while naturally occurring radioisotopes, i.e. (40)K, (226)Ra, and (228)Ra, were 568, 18 and 24 Bq kg(-1), respectively, in surface sediments. The natural radionuclide activities reached their highest levels near petrochemical, phosphate and fertilizer processing facilities. Average (137)Cs activities were generally up to ten times higher than in Middle Eastern marine sediments and lower than those in Northern European sediments.

The usability of tree barks as long term biomonitors of atmospheric radionuclide deposition.

In view of the lower radionuclide activities of moss and lichen, tree barks can be used as biomonitors of radioactive contamination, regardless of the contribution of soil uptake. The present study was conducted to determine the activity concentrations of (137)Cs, (40)K, (232)Th and (238)U in the barks of pine (Pinus nigra) and oak (Quercus petraea) trees collected from the Thrace region in Turkey. By considering the previous studies carried out in the same region, it is noticed that among lichen, moss, oak bark and pine bark, oak bark is the best accumulator of (137)Cs and natural radionuclides.

The effects of physicochemical properties on gamma emitting natural radionuclide levels in the soil profile of Istanbul.

The inventory of gamma-emitting radionuclides was determined in soil samples collected at six depth levels, from 15 locations in Istanbul metropolis. The activity concentrations of (232)Th, (238)U, (40)K were measured by means of gamma spectrometry. The average activity concentrations of (232)Th, (238)U, (40)K in the 30-cm depth soil were found as 32.1, 27.4, 393.1 Bq kg(-1), respectively. The mean value of the absorbed dose rate (D), annual effective dose equivalent (AEDE) from the outdoor terrestrial gamma radiation, Ra equivalent activity (Ra(eq)), and the external hazard index (H(ex)) were calculated as 48.7 nGy h(-1), 59.7 muSv, 104.1 Bq kg(-1), and 0.28, respectively. The effects of organic matter content, textural properties, and pH value of soil samples on the natural radionuclide levels were also investigated. The relations between natural radionuclide level and the physical and chemical properties of studied soil samples were mainly clarified with cluster analysis and Pearson correlation.

(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. Such effects, far from representing a threat to human populations or the environment, reflect a persistent signature of the Chernobyl fallout in this area.

Heavy metal pollution in surface sediment and mussel samples in the Gulf of Gemlik.

Sediment quality data provide essential information for evaluating ambient environmental quality conditions. An evaluation is presented of heavy metal pollution, on the basis of statistical analysis of metal concentrations from the sediments of the Gulf of Gemlik, southeastern Marmara Sea, Turkey, which has been subject to high levels of pollution. The ranges for heavy metal concentrations (Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) at the <63 microm grain size were higher when compared with those obtained from >63 microm fractions. Not only large industrialized seaports but also resort areas throughout the Gulf are flagged as hotspots for elevated concentrations, generally higher compared to those from the other Turkish marine environment. The highest concentrations of Cr, Pb and Ni were measured in the outer part of the Gulf, while the highest concentrations of Cu were documented offshore the main rivers. While the concentrations of Cr, Fe, Mn and Ni in some stations approach the severe effect level given in various sediment quality guidelines, the concentrations of the most human-related metals (Cd and Zn) in the mussels collected from the Port Mudanya were higher than the acceptable values for human consumption set by various healthy organizations.

Radioactivity concentrations and dose assessment in surface soil samples from east and south of Marmara region, Turkey.

The activity concentrations of 137Cs, 40K, 232Th, 238U and 226Ra were measured in surface soil samples from East and South of Marmara region, Turkey. The physico-chemical parameters (organic matter, CaCO3 contents and pH-value) of the soil samples were determined in the samples collected from 100 sampling stations. The average activity concentrations of 137Cs, 40K, 232Th, 238U and 226Ra were found to be 27.46+/-21.84, 442.51+/-189.85, 26.63+/-15.90, 21.77+/-12.08 and 22.45+/-13.31 Bq kg(-1), respectively. The mean value of total annual external gamma radiation dose equivalent for the natural radionuclides was calculated to be 54.86 microSv. The current data were compared with those found in the other locations of Turkey and different countries.

Heavy metal levels in biota and sediments in the northern coast of the Marmara Sea.

Concentration of Cd, Co, Cr, Ni, Zn, Fe, Mn, Pb and Cu were determined in biota and sediment samples collected from the Marmara Sea in Turkey. The levels of Zn, Fe, Mn, Pb and Cu in the macroalgae are higher than previous studies in the Marmara Sea. Moreover, Cu and Zn concentrations at the present study are significantly high than Bosphorus and Black Sea algae. The order heavy metal concentrations in the mussel samples was: Fe > Zn > Ni > Mn > Cu > Pb > Cr > Cd > Co. The metal concentrations are generally lower when compared with the Black Sea mussels except Pb. At the same time, concentrations of Pb, Cu and Zn in the mussel species are lower when compared with the results in the Aegean Sea. The ranges of Mn and Cu in the tested fish samples are higher than Black Sea fish. On the other hand, Cd, Co, Cr, Zn and Pb concentrations are lower. The northern coast of the Marmara Sea having the highest metal concentrations in sediments as follows: Co, Cr, Ni, Fe at Sarköy; Pb, Cu at M. Eregli; Cd, Zn, Mn at Menekse. The heavy metal levels in the sediment samples are lower than other areas in the Marmara Sea.