Levels of cesium radionuclides in lichens and mosses from the province of Ordu in the Eastern Black Sea area of Turkey

Chemobyl nuclear power plant accident in Ukraine in April 26, 1986 has affected Scandinavia and European countries, the Balkans and the northside of Turkey. Radioactive clouds depending on meteorological conditions had contaminated soil surface and flora in the region of Thrace and the seaside of the Black sea. This study has been done on mosses and lichens in which radioactive isotopes can live for a long time. These specimens have been collected in various regions of Ordu located in the Eastern Black Sea region of Turkey. On the basis of the results of this study the geographic distribution of pollution on the flora has been done.     

Chernobyl-derived radiocesium in mosses in the Black Sea area

Radiocesium (¹³⁴Cs and¹³⁷Cs) activity levels in mosses from the Black Sea area, northern Turkey, are reported following the Chernobyl accident during the period of 1989–1991. The cesium radionuclides were detected and measured in all the samples but other longlived radionuclides such as¹⁴⁴Ce and¹⁰⁶Ru were measured in only one sample. The present data support the fact that radioactivity monitoring in mosses can be useful to determine the lasting effect of radioactive contamination.     

Levels of natural and artifical radioactivity in sediments in the Eastern Black Sea of Turkey

Sediment samples collected from the Eastern Black Sea in 1993 from 15 sampling stations of different depths have been analyzed. Natural and artifical radionuclide activity levels in offshore sediment samples from the Eastern Black Sea in Turkey are reported about seven years after the Chernobyl accident. The purpose of this paper is to follow up the earlier study and present results for the distributions of radionuclides in sediments of the Black Sea.     

Chernobyl radioactivity on the Black Sea coast of Turkey

After the Chernobyl reactor accident, Eastern Black Sea coast was one of the heavily contaminated regions of Turkey. Clouds loaded with radioactive isotopes arrived the region on May 1986 and emptied their contents with the heavy rains that are frequently seen in the region. In order to asses the current level of contamination, several different samples, moss, lichen, litter, surface soil and soil cores were collected on August 1994. Samples were brought to the laboratory and their moisture, pH and organic matter contents were determined. Gamma-ray spectra of the samples were collected with a HpGe detector. ¹³⁷Cs was the major isotope observed. Activity of most litter samples were below 1000 Bq/kg, while most of the moss samples had activities below 5000 Bq/kg, there were a few with higher ¹³⁷Cs activities. Surface soil samples generally had activities less than 2000 Bq/kg and depth profiles of cesium activities in the soil cores showed regional variations.     

Chernobyl radioactivity on the Black Sea coast of Turkey

After the Chernobyl reactor accident, Eastern Black Sea coast was one of the heavily contaminated regions of Turkey. Clouds loaded with radioactive isotopes arrived the region on May 1986 and emptied their contents with the heavy rains that are frequently seen in the region. In order to asses the current level of contamination, several different samples, moss, lichen, litter, surface soil and soil cores were collected on August 1994. Samples were brought to the laboratory and their moisture, pH and organic matter contents were determined. Gamma-ray spectra of the samples were collected with a HpGe detector. (137)Cs was the major isotope observed. Activity of most litter samples were below 1000 Bq/kg, while most of the moss samples had activities below 5000 Bq/kg, there were a few with higher (137)Cs activities. Surface soil samples generally had activities less than 2000 Bq/kg and depth profiles of cesium activities in the soil cores showed regional variations.     

Composite sorbents for recovery of cesium radionuclides

Sorption properties of composite sorbents produced by electrochemical deposition of a siloxaneacrylate emulsion impregnated with transition metal ferrocyanides onto a fibrous carbon matrix for cesium radionuclides were studied.     

Decontamination of spent ion-exchange resins contaminated with cesium radionuclides

Possible causes of the occurrence of radioactive contamination irremovable by acid–base regeneration of ion-exchange resins used in treatment of process media and liquid radioactive waste have been studied. It has been found that most of the irremovable cesium radionuclides are bound to inorganic deposits on the surface and in the bulk of ion-exchange resin granules. The nature of inorganic inclusions has been investigated on real and model spent ion-exchange resins (SIER). A method has been proposed for decontaminating SIER using resorcinol–formaldehyde resins selective to cesium radionuclides. Such an approach has been shown to be promising for deep decontamination of SIER.     

Sorption of cesium radionuclides with composite carbon fibrous materials

Sorption of composite sorbents produced by a combined method of thermal treatment and electrochemical and chemical deposition of transition metal ferrocyanides stabilized with latex emulsions onto a fibrous carbon matrix for cesium radionuclides was studied.     

Experimental determination of k 0 nuclear data for the cesium radionuclides

The current (official) k ₀ nuclear data for the cesium radionuclides was determined circa 1987 and was partially adopted from older literature. In this work we aimed at the redetermination of experimental k ₀, Q ₀ and $\bar{E}$ _r factors with metrological care. The results are in good agreement with more recent results from other authors. Our Q ₀ and $\bar{E}$ _r values were 2–15 and 25 % different, respectively. The k ₀ factors were determined according to the cadmium subtraction technique, resulting in values 3–7 % different than the official ones. Our precision and accuracy is discussed.     

Radionuclides in a sediment trap and bottom sediment samples from the eastern Turkish coast of the Black Sea

Summary Radionuclide (¹³⁷Cs, ²³⁸U, ²³²Th and ⁴⁰K) concentrations were determined in a sediment trap and bottom sediment samples collected from a station at the eastern Turkish coast of the Black Sea. The specific activity of the ¹³⁷Cs radionuclide in the settling particles ranged from 0.04±0.01 to 0.10±0.02 Bq^. g^-1dry weight. The calculated flux rate of the ¹³⁷Cs was between 0.37 and 2.59 Bq^. m^-2. d^-1in the sampling periods of 2002 and 2003. The ¹³⁷Cs concentration in the bottom sediment profile were between 0.039±0.013-9.083±0.017 Bq^. g^-1dry weight in the same station. The vertical profile of the radionuclides suggests that they have little mobility during the 17 years after the Chernobyl accident.     

Activity concentrations of selected artificial and natural radionuclides in water and sediment samples from the North Western Black Sea, 1999

Radioactive concentrations of several artificial and natural radionuclides were determined in water and sediment samples collected from various locations in the NW Black Sea in December 1999. For water samples, ⁹⁰Sr and ¹³⁷Cs activity concentrations were of approximately 11 mBq/l and 26.3-41.2 mBq/l, respectively. The concentration of tritium ranged from 7 to 24 T.U. In sediment samples, maximum concentrations of ¹³⁷Cs, ^239+240Pu and ²⁴¹Am were found of 128±6 Bq·kg^-1, 1.8±0.1 Bq·kg^-1 and 0.05±0.04 Bq·kg^-1, respectively. For U and Th radionuclides, the concentrations ranged from 20-80 Bq·kg^-1 and 30-50 Bq·kg^-1, respectively. The results were consistent with those reported in earlier research for the Black Sea. This revised version was published online in July 2006 with corrections to the Cover Date.     

Distribution of activity concentration and dose rates in selected coastal areas on western and eastern Black Sea

Radioactivity measurements were performed, at the east (Georgia) and west (Romania) part of the Black Sea, for natural radionuclides and ¹³⁷Cs in collected water and sediment samples using lab-based and in situ gamma-ray spectrometry. The activity concentrations of ¹³⁷Cs at Georgian area in the sediment and seawater ranged between 20 to 50 Bq kg⁻¹ and 8 to 25 Bq m⁻³, respectively while at the Romanian area the activity concentration ranged from 10 to 30 Bq kg⁻¹ and 3 to 15 Bq m⁻³, respectively. The activity concentration values of ⁷Be at the Georgian area reached values up to (30 ± 4) Bq kg⁻¹. The induced dose rates to marine organisms in both areas estimated by the ERICA assessment tool were much lower than the screening value of 10 μGy h⁻¹.

     

Deposition of fission product radionuclides in lichens and coniferous plants in Turkey

The effects of the Chernobyl disaster on lichens and pines, which are widely distributed in northern and western Turkey, have been examined within the four years between 1986–1990. Analyses of the plants studied by -spectrometry and spectrophotometric techniques have shown that the highest radioactive pollution was observed in the Pseudevernia furfuracea. The effects of Chernobyl on the ecosystem have been examined by comparing different plant species from the point of view of their reception and accumulation of fallout radionuclides.     

Levels and effects of natural radionuclides in soil samples of Garhwal Himalaya

Distribution of natural radionuclide gives significant parameter to assess the presence of gamma radioactivity and its radiological effect in our environment. Natural radionuclides are present in the form of ²²⁶Ra, ²³²Th and ⁴⁰K in soil, rocks, water, air, and building materials. Distribution of natural radionuclides depends on the type of minerals present in the soil and rocks. For this purpose gamma spectrometer is used as tool for finding the concentration of these radionuclides. The activity concentration of naturally occurring radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in these soil samples were found to vary from of 8 ± 1 Bq/kg to 50 ± 10 Bq/kg with an average 20 Bq/kg, 7 ± 1–88 ± 16 Bq/kg with an Average 26 Bq/kg and 115 ± 18–885 ± 132 Bq/kg with an average 329 Bq/kg, respectively. In this paper, we are presenting the radiological effect due to distribution of natural radionuclide present in soil of Garhwal Himalaya.     

Selected radionuclides and heavy metals in skeletons of birds of prey from eastern Poland

Results of determination of ¹³⁷Cs, ⁹⁰Sr, ⁴⁰K, ^239+240Pu, and heavy metals: Mn, Zn, Pb, Cd, Ni, Cr, Co, and Cu in skeletons of 15 species of birds of prey from Eastern Poland were presented. The greatest amounts of ¹³⁷Cs and ⁹⁰Sr (70 Bq/kg and 33 Bq/kg, respectively) were found in rough-legged buzzards (Buteo lagopus), winter visitors, coming from former soviet nuclear test places. Concentrations of ^239+240Pu in raptors were negligible, only lesser-spotted eagles (Aquila pomarina) revealed slightly higher values. Median concentrations of ¹³⁷Cs and ⁹⁰Sr in raptors which feed predominantly on small mammals were higher in comparison to concentrations found in other ones preferring different trophy. The most noticeable was a very high lead concentration (reaching above 600 mg/kg) in birds which utilize un-retrieved hunting casualties as their prey.     

Monitoring of anthropogenic and natural radionuclides and gamma absorbed dose rates in eastern Anatolia

The distribution of the anthropogenic (¹³⁴Cs and ¹³⁷Cs) and natural (²³⁸U, ²³²Th and ⁴⁰K) radionuclide concentrations were studied in soil, foodstuff and bioindicator samples collected from the near site of the Medzamor Nuclear Power Plant at the border of eastern Anatolia of Turkey. For some time, the gross-a and b-concentrations were also determined in the water samples of the region and the absorbed dose rates in air at 1 m above ground were measured. The results showed no additional artificial contamination from the Medzamor Nuclear Power Plant before June 1996.     

Extraction chromatographic separation of radionuclides of strontium,cesium and barium with the use of TVEX-DCH18C6

Extraction chromatographic behaviour of cesium, barium and strontium on TVEX impregnated by crown-ether dicyclohexyl-18-crown-6 was studied. Data obtained were used as the base of the technique of radiostrontium isolated from environmental objects.     

Adsorption — Desorption equilibria of some radionuclides in sediment — Sea water system

Chemical and physical properties of Suez Canal bottom sediments (SCBS) and sea water at port Tawfeek area, the south entrance of Suez canal, have been studied. The SCBS was separated into its size fractions (natural sediment, sand, silt and clay). These different sediment fractions were allwed to be in equilibrium with⁸⁹Sr,⁶⁰Co and¹³⁴Cs solutions. Desorption studies were carried out on these contaminated sediments.     

Iodine-containing complexes of the Black Sea algaPhyllophora nervosa

Iodine-containing complexes have been isolated from a Black Sea red alga. Information is given showing their carbohydrate nature. The causes of the hydrophobic peptide-peptide interaction in the complex are discussed.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Physicochemical Institute, Academy of Sciences of the Ukrainian SSR, Odessa. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 772–776, November–December, 1983.