Natural and artificial radioactivity in Emendere thermal spring area in Western Anatolia

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1 See discussions, stats, and author profiles for this publication at: Natural and artificial radioactivity in Emendere thermal spring area in Western Anatolia Article in Journal of Radioanalytical and Nuclear Chemistry June 2003 DOI: /A: CITATIONS 17 READS 33 4 authors, including: Gursel Karahan 4 PUBLICATIONS 29 CITATIONS SEE PROFILE Available from: Gursel Karahan Retrieved on: 20 September 2016

2 Journal of Radioanalytical and Nuclear Chemistry, Vol. 256, No. 3 (2003) Natural and artificial radioactivity in Emendere thermal spring area in Western Anatolia S. Topcuoğlu,* G. Karahan, N. Güngör, Ç Kırbaşoğlu Çekmece Nuclear Research and Training Center, PO Box 1, 34831, Atatürk Airport, Istanbul, Turkey (Received June 6, 2002) The distribution of the naturally occurring radionuclides 238 U, 232 Th, 226 Ra, 40 K and 210 Po and an anthropogenic radionuclide 137 Cs in foodstuff, indicator organism sediment and soil samples in Emendere thermal spring area in western Anatolia were studied by alpha- and gammaspectrometry. At the same time, the gross-α and β concentrations are also determined in the mentioned samples and the thermal spring and other water samples. The results obtained showed that Emendere thermal spring and Emendere stream waters are unsuitable for consumption as drinking purpose. On the other hand, the people who live around the thermal spring area face no risk with consumption of the foodstuffs. Introduction The Emendere thermal spring area is located in the western part of Anatolia in Turkey. The thermal spring spreads from a geological fault. This isothermal (33 C) spring water is running to the Emendere stream and emptying into the Çaygören barrage lake. The physicalchemical properties, ionic compositions and radioactivity concentrations of the thermal spring water were determined in In this report, the gross-α, gross-β and 222 Rn concentrations were given to be 0.79, 0.35 and 307 Bq. l 1, respectively. This beneficial hot mineral water has a ph of 6.6 and contains bicarbonate and calcium. The flow rate of the water is calculated to be 135 liters per second. It is recommended for kidney diseases. The thermal water is also used for irrigation of the Emendere cultivation area. Natural radioactivity has been a feature of our environment since its origin. In this respect, the natural radionuclides in the Emendere region mainly enter from hot spring water. Nowadays, the natural radionuclide concentrations in terrestrial and aquatic environments are increased from the fossil fuel industry, phosphate industry, oil industry and fertilizers. 2 3 Up to date, there were few studies to quantify the effect of local enhanced sources of natural radionuclides on the concentrations in foodstuff, bioindicator organisms, sediments and soil samples. 4,5 In this study, the naturally occurring radionuclides ( 238 U, 232 Th, 226 Ra, 40 K and 210 Po ), gross-α and gross-β concentrations have been studied in the Emendere area. For comparative purpose, the concentrations of 137 Cs radionuclide in the samples were also investigated. In addition, the gross-α and β concentrations are also determined in five water samples of the region. Experimental The location of sampling sites are shown in Fig 1. All samples were collected during March After collection, the samples were returned to the laboratory as soon as possible, cleaned and stored in a refrigerator. The surface water samples were collected from five stations in 5-liter bottles. The bottles were cleaned using a modified procedure. 6 The bottles were first soaked in 10% HNO 3 for 48 hours, then in deionized water for 5 minutes, and finally rinsed three times with distilled water. All water samples were stored in plastic vials for subsequent preparation and analysis. The analysis procedure of the gross-α and gross-β activities in the water samples was previously described. 7 Fig. 1. Sampling stations in the Emendere thermal spring basin in western Anatolia; 1: Emendere thermal spring, 2: Emendere stream, 3: Çaygören barrage, 4: Salavat water, 5: Sındırgı pump water * stopcuoglu@superonline.com /2003/USD Akadémiai Kiadó, Budapest 2003 Akadémiai Kiadó, Budapest Kluwer Academic Publishers, Dordrecht

3 Lettuce, mallow, cabbage, corn flour, wheat flour, haricot bean, chicken meat, carp fish and rudd fish were selected as foodstuff samples of the region. The edible leaves of green vegetables were rinsed in distilled water to remove soil particles and other materials. The samples were dried at 85 C (to constant weight) and homogenized. The carp and rudd fishes were collected from the Emendere stream and Çaygören barrage lake, respectively. The muscle samples of the fishes were prepared from tail parts of minimum 6 individuals of each species. The chicken meat and muscle tissues of the fishes were pooled and freeze-dried for 7 10 days to a constant weight. Lichens, mosses and gastropode species were selected as bioindicator organisms. The lichen and moss samples were collected from the rocks and trees near the Emendere stream. The samples were separated from bark substrate and other contaminating materials. The samples were dried at 85 C (to constant weight) and homogenized. The similar sized (0.6±0.1 g) gastropod species were collected from the Emendere thermal spring water. More than 100 individuals of the species were broken into pieces and freeze-dried for 5 days to a constant weight. The sediment samples were taken from the Emendere thermal spring, Emendere stream and Çaygören barrage by using a Hidro-Bios sediment corer. The sediment cores were wrapped in polyethylene films on the location, cut into 3-cm slices on plastic sheeting in the laboratory. Three soil samples were collected along a circle of 1 m, of the surface 100 cm 2 at a depth of 2 cm from not cultivated area of the Emendere region. The sediment and soil samples were dried at 85 C and homogenized. The dry residues of the water and dry powders of the other samples were quantitatively transferred in 5 cm diameter stainless steel planchetts. The gross-α activities were measured by a gas flow proportional counting system (Ortec 4020 nim modular). The gross-β activities were measured by one channel low background counting system (Tracerlab Ommi/Guard). The counting time was 1000 minutes and 100 minutes for gross α and β, respectively. The concentrations of 238 U, 232 Th, 226 Ra, 40 K and 137 Cs were determined by gamma-ray spectrometry (Canberra, 85). The sample powders were pressed by hand into the special plastic cups of the instrument. The cups were placed directly on the detector of the HpGe and its resolution (FWHM) was 1.8 kev (at kev for 60 Co).The energy dependent efficiency calibrations were done with a solid nuclide mixture of the Amersham gamma-reference source that contained known activities of 106 Cd, 57 Co, 139 Ce, 113 Sn, 137 Cs, 88 Y and 60 Co. The peak analyses of all counted samples were made by using Spectran-At software on IBM-AT personnel computers. The counting time was 48 hours. The measurement of 210 Po was made using a standard method. The concentration of 210 Po in wet or dry samples were performed starting with a standard addition of a known activity of 209 Po as isotopic tracer. Samples were completely dissolved with mineral acids (HNO 3, HCL, H 2 O 2 ). After evaporation, polonium was plated onto a silver disc in 0.5M HCl in presence of ascorbic acid. The silver discs were counted by silicon surface barrier detectors (Model BU AS) connected with a PC. Results Measurements of gross-α and gross-β activity concentrations in the water samples are presented in Table 1. The global-α concentrations in the Emendere thermal spring and Emendere stream are significantly higher than those in the other water samples. At the same time, the global-β activity in Emendere spring water was also significantly higher among the tested water samples. The results of the foodstuffs in Emendere area for the selected radionuclides and gross-α and gross-β activities are given in Table 2. The gross-α activity is present in higher concentration in cabbage (74±5.1 Bq. kg 1 ) than the haricot bean (13.4±1.4 Bq. kg 1 ) and carp fish (22±2.1 Bq. kg 1 ). Generally, the gross-α in the other foodstuffs were found to be below the lower limit of detection. The gross-β in the foodstuff samples were found in the range of 1±0.2 and 460±14.1 Bq. kg 1. The concentrations of 238 U in cabbage and carp fish samples are higher than those in the other foodstuffs. The 232 Th contents of mallow and cabbage samples were found to be 21.3±12.1 and 45.5±5.2 Bq. kg 1, respectively. On the other hand, the 232 Th level of other samples was low and not detectable. The 226 Ra was present in higher concentration in carp fish than in the other fish species. However, the 226 Ra radionuclide was not detected in other samples of the foodstuff except of the wheat flour. None of the foodstuffs concentrated 137 Cs, although the cabbage sample accumulated 5.8±2.4 Bq. kg 1. The 210 Po was present in higher concentrations in cabbage and rudd fish than in other similar foodstuff samples. Table 1.Radioactivity concentrations (in Bq. l 1 ) of water at five sampling stations Sampling sites Gross-α Gross-β Emendere thermal spring 0.37± ±0.17 Emendere stream 0.32± ±0.06 Çaygören barrage 0.05± ±0.03 Salavat water 0.05± ±0.02 Sındırgı pump water 0.05± ±

4 All radioactivity data refer to dry weight concentrations except of 210 Po in chicken meat and fish samples. Characteristic water content of the foodstuffs was found to be 88, 2, 10, 71 and 70 as percent in green vegetable, flour, grain, chicken meat and fish muscle, respectively. Radioactivity concentrations of bioindicator organisms are given in Table 3. The gross-α, gross-β, 238 U, 226 Ra levels are significantly higher in gastropod samples than in lichens and moss species. On the other hand, 137 Cs and 210 Po concentrations in lichen and moss species are higher than the gastropod samples. The moss species showed a higher potential to concentrate all radionuclides. The gross-α, gross-β, 238 U, and 226 Ra concentrations in Emendere thermal spring sediment are significantly higher than the in other sediment and soil samples (Table 4). The radionuclides of 238 U, 232 Th and 226 Ra in the sediment samples are almost uniformly distributed, whereas the gross-α decreased and the gross-β increased with dept. The 238 U and 226 Ra concentrations in the soil samples were higher than in the Emendere stream and Çaygören barrage sediments. The 137 Cs radionuclide in sediment samples increased with depth. The concentrations of 137 Cs and 210 Po in the soil sample were 15±0.5 and 66±8 Bq. kg, respectively. Table 2. Radioactivity concentrations (in Bq. kg 1 dry wt.) in selected foodstuffs Sample Gross-α Gross-β 238 U 232 Th 226 Ra 40 K 137 Cs 210 Po Lettuce b.d.l. 111± ±499 b.d.l. 0.05±0.01 Mallow b.d.l. 460± ± ±12.1 b.d.l. 737±75 b.d.l. Cabbage 74±5.1 46± ± ±5.2 b.d.l. 766±40 5.8± ±0.29 Corn flour b.d.l. 1± ±1.9 b.d.l. b.d.l. 56±40 b.d.l. b.d.l. Wheat flour b.d.l. 6± ±2.0 b.d.l. 6.1± ±45 b.d.l. 0.35±0.18 Haricot bean 13±1.4 10± ±1.6 b.d.l. b.d.l. 410±41 b.d.l. Chicken meat b.d.l. 9± ±1.8 b.d.l. b.d.l. 309±41 b.d.l. 0.09±0.02* Carp fish 22±2.1 26± ±6.0 b.d.l. 44.1± ±123 b.d.l. b.d.l.* Rudd fish b.d.l. 22± ±2.4 b.d.l. 10.1± ±51 b.d.l. 3.61±0.54* b.d.l.= Below detection limit. * Polonium concentrations are given in wet weight. Table 3. Radioactivity concentrations (in Bq. kg 1 dry wt.) in bioindicator organisms Bioindicator Gross-α Gross-β 238 U 232 Th 226 Ra 40 K 137 Cs 210 Po Lichen 244±7.9 16± ±21.7 b.d.l ±64.3 b.d.l. 44.1± ±12 Moss 692± ± ± ± ± ± ± ±27 Gastropod sp. 3484±19 109± ± ± ±15.7 b.d.l. b.d.l. 109±15 b.d.l. = Below detection limit. Table 4. Radioactivity concentrations (in Bq. kg 1 dry wt.) in sediment and soil samples Sample/Station Gross-α Gross-β 238 U 232 Th 226 Ra 40 K 137 Cs 210 Po Sediment S1 0 3 cm 3440±49 133± ± ± ± ±21 3.1± cm 1408±14 786± ± ± ± ±10 1.9± cm 1096± ± ± ± ± ± ± cm 1764± ± ± ± ± ±13 4.9±0.6 Sediment -S2 0 3 cm 660±11 46± ± ± ± ±13 1.5± cm 340± ± ± ± ± ±31 1.3± cm 292± ± ± ± ± ±17 n.d 9 12 cm 364±4.9 61± ± ± ± ±18 2.1±0.5 Sediment S3 0 3 cm 412± ± ± ± ± ±14 5.1± cm 238± ± ± ± ± ±41 7.1± cm 293± ± ± ± ± ±22 9.8± cm 400± ± ± ± ± ±19 9.7±6.2 Soil 0 2 cm 383±4.4 41± ± ± ± ±11 15±0.5 66±8 S1: Emendere thermal spring. S2: Emendere stream. S3: Çaygören barrage. 397

5 Discussion Recommended screening levels for radioactivity in drinking water samples are given to be 0.1 Bq. l 1 for gross-alpha and 1 Bq. l 1 for gross-beta radiation. 8 As a result we can say that the water of the Emendere thermal spring and Emendere stream are unsuitable for drinking. However, the other water sources can be used as drinking water without any treatment of the supply to reduce the concentrations of radioactive contaminants. None of the tested foodstuff samples concentrated any great degree of the determined radioactivities or radionuclides, and only cabbage showed a potential to accumulate gross-α, 238 U and 232 Th. The carp fish accumulated high level of 226 Ra. As a result we can say that the people who live around the thermal spring area have no risk with the consumption of the foodstuffs. However, in Emendere thermal spring area abnormally high concentrations of gross-α, 238 U and 226 Ra were observed in gastropod species and sediment samples collected at one of the sampling points. This also showed no clear evidence suggesting any anthropogenic enhancement of natural radionuclides levels without 210 Po. The tested radionuclides or radioactivity concentrations in moss species were higher than in lichen species. It is well known that lichen and moss species could be used as efficient monitors for fallout radionuclides. 9,10 Sediments have been widely used as environmental indicators and they play an important role in the assessment of radioactive contamination in natural waters. A previous study indicated that the enrichment rate of pollutants in river sediments reflects the upstream contamination sources. 11 In the present study, the grossα, 238 U and 226 Ra levels in sediment samples gradually decreased from the Emendere thermal spring to the Çaygören barrage station. Therefore, we can assume that the enrichment of the activity comes mainly from the leaching of the volcanic rocks at the Emendere thermal spring station. The 238 U and 226 Ra concentrations of the Emendere thermal spring sediment samples were significantly higher than in hot spring sediments in Taipei. 12 On the other hand, 232 Th concentrations in Taipei sediments were generally higher in comparison to the present results. In a previous study, the concentrations of 238 U and 40 K radionuclides in Istanbul uncultivated soil samples were found to be lower than the typical value for this part of Anatolia. 13 On the other hand, 232 Th concentrations were higher in the Istanbul region. At the same time, the 226 Ra concentration in untreated soil sample in north-western Greece was lower than the concentration of the radionuclides in this work. 2 In another study, the concentration of the natural radionuclides in surface soil in a coal fly ash disposal site ranged from 7.5 to 77 Bq. kg 1 in dry weight. 14 These differences among the results depend on the 222 Rn emanation rate from soil after deposition. The 222 Rn concentration in Emendere thermal spring water was found to be 307 Bq. l 1. 1 This result showed that the high 222 Rn emanation occurred after wet deposition on the Emendere soil surface. Report on concentrations of 210 Po in green vegetable and cereal samples in England showed ranges of and Bq. kg 1 (wet weight), respectively. 4 Converting these data to dry weight concentrations produces activities agreeing with those measured in the present work. 210 Po concentrations in chicken and fish samples in Portugal were found to be 0.15 and 6.0 Bq. kg 1 wet weight. 15 These concentrations are higher than those in the samples of this study. The 137 Cs radionuclide is now present in Anatolia after the Chernobyl accident and it is remaining in the soil of a few cm of thickness. The high 137 Cs concentrations in lichen and moss species suggest that these organisms are valuable monitors of fallout radionuclides. * We acknowledge the financial support for the sample collection of this work provided by the Turkish Atomic Energy Authority. We also thank to F. AYDINCIK and I. AKKURT for their valuable assistance. References 1. Publication of Medicine Faculty of I.U. 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