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Öğe Activity concentrations of natural radionuclides and Cs-137 in soils of coniferous forest sites in West Anatolia(Springer, 2011) Karadeniz, Ozlem; Yaprak, GunseliThe surveys of natural gamma-emitting radionuclides and Cs-137 in surface soils of coniferous forest sites in and around Izmir were conducted during 2003-2004. The soil samples were collected from three different depths of 15 forest sites, particularly local wild edible mushrooms areas. The average activity concentrations and ranges of the natural radionuclides in the soils were as follows: 30 (14-51) Bq kg(-1) of Ra-226; 40 (17-79) Bq kg(-1) of Th-232; and 581 (308-879) Bq kg(-1) of K-40. Moreover, the values of Cs-137 activity concentrations averaged over the depth sections varied from 20 to 82 Bq kg(-1) with a mean value of 52 Bq kg(-1). Accordingly, the levels of the studied natural radionuclides in the forest soils were within the range specified by UNSCEAR (2000) report for regular soils as well as the agricultural soils from the West Anatolia, while the measured activity levels of Cs-137 in the forest soils were still high in contrast to agricultural soils after 16 years from the deposition of Chernobyl fallout.Öğe An assessment on levels of radionuclides and trace metals and radiological risk to marine biota in the North-Eastern Mediterranean Sea(Springer Heidelberg, 2023) Koraltan, Idris; Guven, Olgac; Asri, Filiz Okturen; Aktas, Ozgur; Aksoy, Ercument; Yaprak, Gunseli; Boztosun, IsmailArtificially produced radionuclides by nuclear reactions are the second type available in the marine environment, in addition to the radionuclides originating from natural sources. Natural radionuclides have been introduced into the environment by several paths of which were unpredictable compared to the anthropogenic activities performed in a controlled manner such as nuclear weapon testing and nuclear fuel reprocessing activities. One major path for radionuclide accumulation to the marine environment from unpredictable sources known to be the river runoffs which transfers the radionuclides deposited over land. In the present study natural-artificial radionuclide activity ((226) Ra, (232) Th, (40) K and Cs-137) and trace metal concentrations (Cd, Co, Cr, Ni, Pb, Mn, Fe, Cu, Zn, K, Ca, Mg and Na) in the coastal areas of north-eastern Mediterranean Sea, and the radiological risk to marine biota (fish and invertebrate species) were investigated. Individuals of seven species belonging to two biota groups were analyzed to evaluate the radionuclide activity levels. Highest activity levels of (226) Ra, Th-232 and (40) K were detected for Mullus barbatus (8.6 +/- 0.8 Bq kg(- 1)), Charybdis longicollis (5.3 +/- 0.4 Bq kg(- 1)) and Pagellus acarne (95.7 +/- 6 Bq kg(-1)) respectively. Highest total dose rate for all evaluated radionuclides was 12.6 nGy h (-1). 226 Ra and 40 K were the two radionuclides with highest contribution to the total dose rate. Our results indicated that there is no radiological risk in the study area. Charybdis longicollis samples were detected to be rich in Mn, Zn and Ca.Öğe Biomonitoring of metals in the vicinity of Soma coal-fired power plant in western Anatolia, Turkey using the epiphytic lichen, Xanthoria parietina(Taylor & Francis Inc, 2011) Gur, Filiz; Yaprak, GunseliIn this study, epiphytic lichen Xanthoria parietina was applied as the biomonitor of air pollution to determine the environmental influence in the vicinity of Soma coal-fired power plant. Thalli of lichen Xanthoria parietina growing on olive, oak and poplar trees were collected with their substrate in 2004-2006. They were taken from 44 different stations located in 3x3 km grids within an area of 30 km in diameter around the Soma power plant near the town of Soma. Lichen samples were analyzed by using the ICP-MS for As, Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb, Se, Th, U, V and Zn elements and their concentrations were mapped. The sample analyses results were evaluated by using the statistical software (SPSS 11). Average element contents of samples were, in descending order, Fe > Zn > V > Pb > Cr > Cu > Ni > As > Co > U > Th > Se > Cd > Hg. Results obtained in the current study were generally found to be higher than the data reported in literature although some lower values exist for Cd, Co, Hg, Ni, Pb elements. The most polluted areas were found to be those in the vicinity of the coal-fired power plant, particularly along the direction of predominant wind and in the corridor which runs from west to southeast direction due to topographic conditions. We believe that this research which is conducted around a coal-fired power plant will shed light on future research on pollution.Öğe Could atmospheric carbon be driving sedimentation?(Springer Heidelberg, 2022) Vinkovic, Andrija; Laptyev, Gennadiy; Yaprak, Gunseli; Slavova, Krasimira; Joksimovic, Danijela; Troskot-Corbic, Tamara; Frontasyeva, MarinaPurpose The objective of this study was to provide insights into the most recent responses of sediments to climate change and their capability to sequester atmospheric carbon (C). Methods Three sediment cores were collected, one from the western Black Sea, and two from the southern Adriatic Sea. Cores were extruded and sectioned into 1 cm or 0.5 cm intervals. Sections were frozen, weighed, freeze-dried, and then weighed again to obtain dry weights. Freeze-dried samples were dated by using lead 210 (Pb-210) and cesium 137/ americium 241 (Cs-137/Am-241). Organic and inorganic C were determined by combustion. Particle size distribution was determined using a Beckman Coulter particle size analyzer (LS 13,320; Beckman Coulter Inc.). Mineralogical analyses were carried out by a Philips X'Pert powder diffractometer. Results Sedimentation and organic and inorganic C accumulation rates increased with time in both the Black Sea and the Adriatic Sea. The increase in accumulation rates continued after the global introduction in the early 1970s of controls on the release of phosphorus (P) into the environment and despite the reduced sediment yield of major rivers (Po and Danube). Therefore, the increased accumulation of organic and inorganic C in the sediments cannot be assigned only to nutrient availability. Instead, we suggest that the increase in organic C is the consequence of the increase in atmospheric C, which has made more carbon dioxide (CO2) available to phytoplankton, thus enabling more efficient photosynthesis. This process known as CO2 fertilization may increase the organic C accumulation in sediments. Simultaneously, the increase of sea temperatures decreases the calcite solubility resulting in increases of the inorganic C accumulation. Conclusion Our results suggest that long-term, general increases in accumulation rates of organic and inorganic C in sediments are the consequence of increases in atmospheric C. This shows that coastal sediments play an important role in C uptake and thus in regulating the Earth's climate.Öğe Dynamic equilibrium of radiocesium with stable cesium within the soil-mushroom system in Turkish pine forest(Elsevier Sci Ltd, 2007) Karadeniz, Ozlem; Yaprak, GunseliMushrooms and soils collected from pine forests in izrnir, Turkey were measured for radiocesium and stable Cs in 2002. The ranges of Cs-137 and stable Cs concentrations in mushrooms were 9.84 +/- 1.67 to 401 +/- 3.85 Bq kg(-1) dry weight and 0.040 +/- 0.004 to 11.3 +/- 1.09 mg kg(-1) dry weight, respectively. The concentrations of Cs-137 and stable Cs in soils were 0.29 +/- 0.18 to 161 +/- 1.12 Bq kg(-1) dry weight and 0.14 +/- 0.004 to 1.44 +/- 0.045 mg kg(-1) dry weight, respectively. Even though different species were included, the concentration ratios of Cs-137 to stable Cs were fairly constant for samples collected at the same forest site, and were in the same order of magnitude as the Cs-137 to stable Cs ratios for the organic soil layers. The soil-to-mushroorn transfer factors of 137Cs and stable Cs were in the range of 0.19-3.15 and 0.17-12.3, respectively. The transfer factors of Cs-137 were significantly correlated to those of stable Cs. (C) 2006 Elsevier Ltd. All rights reserved.Öğe Indoor radon measurements in the granodiorite area of Bergama (Pergamon)-Kozak, Turkey(Oxford Univ Press, 2012) Karadeniz, Ozlem; Yaprak, Gunseli; Akal, Cuneyt; Emen, IpekIndoor radon levels in 20 dwellings of rural areas at the Kozak-Bergama (Pergamon) granodiorite area in Turkey were measured by the alpha track etch integrated method. These dwellings were monitored for eight successive months. Results show that the radon levels varied widely in the area ranging from 111 to 72711 Bq m(3) and the geometric mean was found to be 63 Bq m(3) with a geometric standard deviation of 2 Bq m(3). A lognormal distribution of the radon concentration was obtained for the studied area. Estimated annual effective doses due to the indoor radon ranged from 0.27 to 18.34 mSv y(1) with a mean value of 1.95 mSv y(1), which is lower than the effective dose values 310 mSv given as the range of action levels recommended by International Commission on Radiation Protection. All dosimetric calculations were performed based on the guidance of the UNSCEAR 2000 report.Öğe Investigation on radiation attenuation properties of natural stone samples traded in Turkey(Elsevier, 2024) Camgoz, Yasemin Isik; Camgoz, Berkay; Yaprak, GunseliAlthough radioprotection is globally regulated for high radiation exposure, formal guidelines concerning natural radiation exposure that causes stochastic radiation effects have not been established. The commonly used absorbers lead, tungsten and bismuth are not appropriate for the radioprotection of the public. The primary barrier against natural radiation is the structural components of buildings, where humans spend approximately 80 % of their lifetime. Natural stones are secondary materials, which are applied to walls and floors as coating. This study focuses on the radiation shielding properties of natural stones. Herein, the samples of marble, granite and sedimentary rock traded in Turkey were examined to determine whether they can serve as passive or alternative radioprotection materials. Notable gamma absorption rates were obtained when an intense gamma source with an energy of 662 key was used. The calculated mass attenuation coefficients were comparable with those of copper and aluminium. The mean mass attenuation coefficient was 0.082 cm2/g for marbles and granites and 0.080 cm2/g for sedimentary rocks. Considering the stochastic effects, the use of the natural stones as construction materials is anticipated to significantly reduce the natural radiation level in inhabitable regions. Furthermore, natural stones can be used in clinics as secondary radiation shields against low-energy gamma and x-rays.Öğe THE NATURAL RADIOACTIVITY CONTENTS IN FEED COALS FROM THE LIGNITE-FIRED POWER PLANTS IN WESTERN ANATOLIA, TURKEY(Oxford Univ Press, 2010) Cam, N. Fusun; Yaprak, Gunseli; Eren, ElifLignite burning is one of the sources of technologically enhanced exposure to humans from natural radionuclides. In the preliminary study, part of the survey, the activity concentrations of (226)Ra, (232)Th and (40)K in 112 samples of feed lignites from seven lignite-fired power plants in Western Anatolia (Seyitomer, Tuncbilek, Orhaneli, Soma, Yatagan, Yenikoy and Kemerkoy) were, therefore, determined by scintillation gamma spectrometry. The ranges of the relevant radionuclides in the lignite samples are as follows: (226)Ra, 23-291 Bq kg(-1); (232)Th, 12-68 Bq kg(-1); and (40)K, 67-284 Bq kg(-1). Taking the coefficient of variation (CV) as a measure of the variability, the CV is also calculated for the natural radionuclides in the feed lignites. Furthermore, the dose rates in the coal-handling areas due to external gamma radiation are found to be within the range specified by UNSCEAR (2000) report.Öğe NATURAL RADIOACTIVITY OF FERTILIZERS WIDELY USED IN THE AGRICULTURAL LANDS OF EGE REGION IN TURKEY(Parlar Scientific Publications (P S P), 2015) Esetlili, Bihter Colak; Yaprak, Gunseli; Anac, DilekThis is a preliminary study to determine the natural radionuclides of the commercial chemical fertilizers and rock phosphates which are widely used in the agricultural lands of Ege region in the west of Turkey. Mainly the fundamental raw materials of all phosphorous (P) containing fertilizers are examined. Gamma spectrometric measurements of Ra-226, Th-232 and K-40 activities were made on sixty-eight straight and compound commercial fertilizers, as well as on the nine phosphate rocks. The activity concentrations of Ra-226 in the phosphate rocks were found to be in the range of 326 and 788 Bq kg(-1) while those of Th-232 and K-40 were found to be much lower, ranging from 50 Bq kg(-1) to levels so low that they were undetectable. Normal super phosphate (NSF) and triple super phosphate (TSP) exhibited relatively higher Ra-226 activities than the rest of studied P based fertilizers. K-40 activities in potassium sulfate and nitrate fertilizers w up to about 10(4) Bq kg(-1). In particular, the activity concentrations of the Ra-226 in NP and the majority of NPK fertilizers, which are the most widely used types in the cultivated soils of the Ege region, appeared much lower, and in some cases, were undetectable. These results are of great significance in terms of sustainable agriculture involving the use of phosphate-based fertilizers.Öğe Prediction of the activity concentrations of Th-232, U-238 and K-40 in geological materials using radial basis function neural network(Springer, 2022) Erzin, Selin; Yaprak, GunseliIn this paper, three individual models and one generalized radial basis function neural network (RBFNN) model were developed for the prediction of the activity concentrations of primordial radionuclides, namely, Th-232, U-238 and K-40. To achieve this, gamma spectrometry measurements of 126 different geological materials were used in the development of the RBFNN models. The results indicated that individual and generalized RBFNN models are quite efficient in predicting the activity concentrations of Th-232, U-238 and K-40 of geological materials.Öğe Reference levels of natural radioactivity and Cs-137 in and around the surface soils of Kestanbol pluton in Ezine region of Canakkale province, Turkey(Taylor & Francis Inc, 2013) Ozturk, Buket Canbaz; Cam, N. Fusun; Yaprak, GunseliThe aim of the study was to conduct a systematic investigation on the natural gamma emitting radionuclides (Ra-226, Th-232 and K-40) as well as Cs-137 in the surface soils from Kestanbol/Ezine plutonic area in Canakkale province as part of the environmental monitoring program on radiologic impact of the granitoid areas in Western Anatolia. The activity measurements of the gamma emitters in the surface soil samples collected from 52 sites distributed all over the region has been carried out, by means of HPGe gamma-ray spectrometry system. The activity concentrations of the relevant radionuclides in the soil samples appeared in the ranges as follows: Ra-226 was 20-521 Bq kg(-1); Th-232, 11-499 Bq kg(-1)and; K-40, 126-3181 Bq kg(-1), yet the Cs-137 was much lower than 20 Bq kg(-1)at most. Furthermore, based on the available data, the radiation hazard parameters associated with the surveyed soils were calculated. The present data also allowed evaluation of some correlations that may exist in the investigated natural radionuclides of the soil samples from the plutonic area in Canakkale province. It is concluded from the above that the concerned region did not lead to any significant radiological exposure to the environment.Öğe Soil-to-mushroom transfer of Cs-137, K-40, alkali-alkaline earth element and heavy metal in forest sites of Izmir, Turkey(Springer, 2011) Karadeniz, Ozlem; Yaprak, GunseliThe present work is devoted to an investigation on the soil to mushroom transfer parameters for Cs-137 and K-40 radionuclides, as well as for some stable elements and heavy metals. The results of transfer factors for Cs-137 and K-40 were within the range of 0.06-3.15 and 0.67-5.68, respectively and the most efficiently transferred radionuclide was K-40. The TF values for Cs-137 typically conformed to a lognormal distribution, while for K-40 showed normal distribution. Statistically significant correlations between Cs-137 soil to mushroom transfer factors and agrochemical soil properties have been revealed. Although the concentration ratios varied within the species, the most efficiently transferred elements seems to have been K, followed by Rb, Zn, Cu, Cd, S, Cs and Hg.Öğe A survey of natural radiation levels in soils and rocks from Aliaga-Foca region in Izmir, Turkey(Oxford Univ Press, 2013) Cam, N. Fusun; Ozken, Ibrahim; Yaprak, GunseliThe gamma spectroscopic analysis of Ra-226, Th-232 and K-40 has been carried out in surface soil samples collected from Aliaga-Foa industrial region. The rock samples as parent materials of the soils are also collected and analysed for relevant radionuclides in order to evaluate the natural radiation levels. In the present study, the mean activity concentrations and ranges of the related radionuclides in the soil samples from 60 sites distributed all over the region are as follows: Ra-226 is 38 (14123) Bq kg(1); Th-232, 63 (27132) Bq kg(1) and K-40, 633 (1411666) Bq kg(1). Meanwhile, the ranges of natural radionuclide activities in the rock samples characterising the region are 4195 Bq kg(1) for Ra-226, 10122 Bq kg(1) for Th-232 and 2641470 Bq kg(1) for K-40, respectively. Based on the available data, the radiation hazard parameters associated with the surveyed soils/rocks are calculated and the results do not exceed the permissible recommended values except for soils originated from Foa rhyolites and tuffs. Furthermore, the collected data allowed for the mapping of the measured activities and corresponding gamma dose rates.Öğe Terrestrial gamma exposure in the granodiorite area of Bergama (Pergamon)-Kozak, Turkey(Springer, 2011) Karadeniz, Ozlem; Ciyrak, Nazan; Yaprak, Gunseli; Akal, CuneytAs higher radiation levels are associated with granite and Bergama (Pergamon) has increasingly become a large market for granite use over the last years, an extensive investigation was started in 2009. Samples from the granites and soils underlying this area were collected and analyzed by HPGe gamma spectrometry system. The specific activities of the naturally occurring radionuclides Ra-226, Th-232, and K-40 were found to be in the range of 29-111 Bq kg(-1) for Ra-226, 35-87 Bq kg(-1) for Th-232 and 698-1100 Bq kg(-1) for K-40 in granite samples. The ranges of Ra-226, Th-232, and K-40 activity concentrations for soils were 32-82, 42-88 and 667-1127 Bq kg(-1), respectively. From these data radiological parameters were calculated and compared with respective data from the UNSCEAR reports.
