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Effects of radionuclides on the recent foraminifera from the clastic sediments of the Çanakkale Strait-Turkey
Journal of African Earth Sciences 131 (2017) 179e182
Contents lists available at ScienceDirect
Journal of African Earth Sciences journal homepage: www.elsevier.com/locate/jafrearsci
Effects of radionuclides on the recent foraminifera from the clastic sediments of the Çanakkale Strait-Turkey Zeki Ünal Yümün a, *, Erol Kam b a b
, Turkey Namık Kemal University, Çorlu Engineering Faculty, Environmental Engineering Departmant, 59860 Çorlu, Tekirdag _ Yildiz Technical University, Faculty of Arts and Sciences, Physics Department, Davutpas¸a Campus, 34220 Esenler/ Istanbul, Turkey
a r t i c l e i n f o
a b s t r a c t
Article history: Received 4 February 2017 Received in revised form 15 April 2017 Accepted 19 April 2017 Available online 22 April 2017
The radionuclides that cause radioactivity accumulate in the sediments as they descend to the seabed, similar to heavy metals. As radionuclides are present on the surface of the sediment or within the sediment, marine benthic foraminifera can be affected by the radioactive pollution. In this study, the habitat of benthic foraminifera was evaluated for radioactive pollution in the Çanakkale Strait, which constitutes the passage of the Marmara Sea and the Aegean Sea. In 2015, seven core samples and one drilling sample were taken from the shallow marine environment, which is the habitat of benthic foraminifera, in the Çanakkale Strait. Locations of the core samples were specifically selected to be pollution indicators in port areas. Gamma spectrometric analysis was used to determine the radioactivity properties of sediments. The radionuclide concentration activity values in the sediment samples obtained from the locations were Cs-137: <2e20 (Bq/kg), Th-232: 17.5 e58.3 (Bq/kg), Ra-226: 16.9e48.6 (Bq/kg) and K-40: 443.7e725.6 (Bq/kg). These values were compared with the Turkish Atomic Energy Agency (TAEK) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) data and environmental analysis was carried out. The Ra-226 series, the Th-232 series and the K-40 radionuclides accumulate naturally and increase continuously due to anthropogenic pollution. Although the Ra-226 values obtained in the study areas remained within normal limits according to UNSCEAR values, the K-40 and Th-232 series values were observed to be high in almost all locations. The values of Cs-137 were found to be maximum 20 in Çanakkale Dere Port and they were parallel to the values in the other places. In the study, 13 genera and 20 species were identified from core and drilling samples. The number of foraminifera species and individuals obtained at locations with high pollution was very low compared to those in non-polluted zones. © 2017 Elsevier Ltd. All rights reserved.
Keywords: Ra-226 Th-232 K-40 Cs-137 Radionuclide Foraminifera Çanakkale Strait
1. Introduction Throughout the world, technological developments can cause radioactive pollution that results from industrial and nuclear waste. Furthermore, radioactive elements with very long lives that occur naturally in the Earth's crust also form a natural radiation level. Every living creature on the Earth is continuously exposed to radioactive substances that are formed by both natural radiation and human activities. Radioactive pollutants entering the marine environments through dry and wet precipitation are also carried to
* Corresponding author. E-mail addresses: [email protected] (Z. Yümün), [email protected] (E. Kam). http://dx.doi.org/10.1016/j.jafrearsci.2017.04.018 1464-343X/© 2017 Elsevier Ltd. All rights reserved.
the sea by streams. As seen in the Chernobyl disaster, transport of contaminated soils to the sea by erosion also contaminates these environments. Water contaminated with radioactive pollutants that is entering the marine environment is circulated between the € sediment and the organisms (Güven and Oztürk, 2005). Benthic foraminifera will be affected by radioactive contamination in marine sediments, especially as they live in sediments on the seabed. Therefore, the habitats of foraminifera were evaluated as pollution indicators in marine environments. Natural radionuclides such as the 238 U series, 232 Th series and 40 K exist in various levels in the soil, sediment, water, plants, and air. The natural radionuclide distribution depends on the geological and geographical conditions of each region (Kurt et al., 2016). Cs-137, one of the artificial radionuclides, has high water solubility and it can move easily. In the ecological environment, the
180
Z. Yümün, E. Kam / Journal of African Earth Sciences 131 (2017) 179e182
presence of Cs-137 indicates nuclear weapons tests or fallout. After the nuclear accidents in 1986, Chernobyl and in 2011, Fukushima, artificial radionuclides such as Cs-137 have mixed with the receiving mediums (e.g., sea, rivers, air, and soil) and have been very quickly transported kilometers from their sources. In particular, nuclear power plants that have been installed in earthquakeprone areas have the potential to be either completely destroyed or damaged by earthquake, causing leaks (e.g., Metsamor Nuclear Power Plant in Armenia) and posing a great threat to worldwide living conditions (Kam, 2016). In this study, natural and artificial radionuclide distributions were investigated by using gamma spectrometry in core sediment samples and drilling samples taken from different points in the Çanakkale Strait. Table 1 shows the values of the radionuclides determined around the Çanakkale Strait in the distribution chart of soil and water radioactivity of the Turkish Atomic Energy Agency. The values given in Table 1 were compared with the radionuclide values obtained in this study and the basis of the high values in the sea € were investigated (Güven and Oztürk, 2005).
Table 2 Core sample coordinates. Sample code
1-Burhanli (Çanakkale) 2-Dereliman (Çanakkale) 3-Eceabat (Çanakkale) 4-Gelibolu (Çanakkale) 5-Kumkale (Çanakkale) 6-Lapseki (Çanakkale) 7-Seddülbahir (Çanakkale) 8-S¸evketiye (Lapseki)
Sample Amount (L)
2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
Coordinates (UTM, 6 Degree) (Y)
(X)
463,791 449,212 445,495 471,306 436,965 473,852 430,862 489,498
4,463,231 4,443,871 4,448,541 4,478,121 4,428,080 4,466,935 4,432,732 4,471,929
2. Materials and methods In this study, one drilling sample was taken from the Çanakkale Strait (BH-7) and eight core samples were taken from eight different locations (Burhanlı, Dereliman, Eceabat, Gelibolu, Kumkale, Lapseki, Seddülbahir, and S¸evketiye) (Table 2 and Fig. 1). Samples were collected with the YUMUN 01 drilling platform. Attention was paid to the existing pollution conditions while taking the core samples and drilling sample. The drilling samples were taken with the drilling platform installed on the sea with the rotary drilling system. However, the core samples were taken by hydraulic pressure method. The cores and drilling cores were divided into 10 cm sections from top to bottom and samples were prepared for foraminifera analysis. Each sample was kept in a 10% H2O2 solution for 24 h, then filtered through a 125 mm to remove the foraminifera. Segregation was carried out using a stereozoom microscope and systematic descriptions of each foraminifera were made. For radionuclide analysis, samples were first prepared for radioactive analysis by keeping them at room temperature in a laboratory environment. Analyses of the prepared samples were performed in the Çekmece Radioactivity and Analytical Measurement Department. The samples were finely powdered by filtering through a 100-mm sieve. The powdered samples were placed in 1000 mL Marinelli test bottles and bottle openings were sealed to prevent air contact. The samples were kept for 40 days after weighing to equilibrate between radium, thorium and other degradation products. Gamma spectrometry analysis (Canberra GX5020) was used with an HPGe detector, which was joined to a coaxial high-purity germanium (Bozkurt et al., 2007). The setup was calibrated by using solid, diverse gamma emitting reference sources in a 1 L Marinelli beaker. The gamma activity relied on 238U series, 609.3 keV; 232Th series, 583 keV; 228Ac, 911.2 keV; 226Ra, 185.7 keV; 137Cs, 661.7 keV; 40 K, 1460,8 keV (UNSCEAR, 2000).
Table 1 Turkey atomic energy agency soil radionuclide values in Çanakkale Strait (Güven and € Oztürk, 2005). Radionuclides
Low (Bq/kg)
High (Bq/kg)
Th-232 Ra-226 K-40 Cs-137
5.00 10.10 50.00 0.00
50.10 75.00 100.00 20.00
Fig. 1. Location map of eight points where core samples and Bore Hole Samples (BH-7) were taken at Çanakkale Strait.
3. Results and discussion 3.1. Geological setting of investigation area The investigated area is the Çanakkale Strait, which constitutes the passage of the Marmara Sea which is part of the strait system connecting the Black Sea and the Mediterranean (Fig. 1). Between the Gallipoli and Biga peninsulas, the Çanakkale Strait is 61 km long, between 12 and 6 km wide, and has a maximum depth of 82 m and an average depth of 55 m (Artüz, 2007). From the geological and morphological point of view, the Çanakkale Strait has undergone quite a complex evolution. Geologically, the Çanakkale Strait extends along the deepest point of a depression formed by Neogene-aged sediments. Both basins of the Çanakkale Strait, the main and Neogene covers, were cut by an Upper Pliocene age abrasion surface descending toward the strait axis. The Strait was formed on the depressions that formed this abrasion surface and later sank with its branches and acquired its current form. The Çanakkale Strait and neighboring area, which was an important settlement in ancient times, also have strategic importance due to its geopolitical position. Surrounded by the Çanakkale Province, the economic activities of the strait are mostly agricultural. Industry and trade have also developed as a result of these agricultural activities.
Z. Yümün, E. Kam / Journal of African Earth Sciences 131 (2017) 179e182
3.2. Radionuclides of sediments in investigation area
181
Table 4 Drilling (BH-7) samples analysis results.
The radionuclide concentration activity values in the sediment samples obtained from the locations were Cs-137 < 2e20 (Bq/kg), Th-232: 17.5e58.3 (Bq/kg), Ra-226: 16.9e48.6 (Bq/kg), and K40 ¼ 443.7e725.6 (Bq/kg). The activity values of the radionuclides of the core benthic foraminifera samples are given in Table 3 and the values of the drilling samples (Bore Hole-7: BH-7) are given in Table 4. These values were compared with the international average values (Table 5). In core samples, K-40 was higher than the world limit values at all locations, Th-232 was below the limit value at three locations and above at four locations, and Ra-226 was below the limit value at five locations and above at two locations. Radionuclides are atoms that have excess nuclear energy, making their unstable. In the samples collected from the upper, middle and lower locations of the drilling, the values of activity for K-40 and Th-232 for the samples taken from the upper and lower locations were above the limit value and below the limit value at the middle locations compared with the international average limit values. R-226 radionuclide was just below the limit at the lower locations of the drilling and below the limit value at the upper and middle locations. Sediment samples have different physical, chemical, geological form and location characteristics; therefore, the obtained numerical results vary. The region's economy has developed based on agriculture, and the industrial facilities use agricultural raw materials. This has increased the use of fertilizers in agricultural activities. The use of potassium-rich fertilizers has enriched the potassium content of the soil. The transport of potassium-rich soils to the sea by erosion appears to increase the radioactivity of the habitat (Table 1). It also suggests that K-40 has the highest absorption activity, as it is high in all regions. Fig. 2 shows the distribution of radionuclides for the seven sample locations in the Çanakkale Strait.
Sample
Radionuclides
Activity ± 2s (Bq/kg)
Measurable Lower Limit (Bq/kg)
BH-7/12 m
K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232
558.0 ± 83.4 10.9 ± 2.3 19.1 ± 2.9 30.1 ± 4.0 380.9 ± 47.3 3.0 ± 0.8 14.3 ± 1.8 13.6 ± 1.7 709.4 ± 68.1 <1.0 46.6 ± 3.7 53.1 ± 4.3
37.50 2.37 4.60 3.81 13.10 1.51 2.49 1.99 5.07 1.03 1.35 1.21
BH-7/18 m
BH-7/23 m
Table 5 International average values (UNSCEAR, 2000). Radionuclides
International Average Limit Values
Th-232 Ra-226 K-40
30 Bq kg1 35 Bq kg1 400 Bq kg1
Numerous foraminifera genus and species were identified from core samples. Nine foraminiferal genus and 11 species were obtained in the core samples, while 13 genera and 20 species were obtained in the drilling samples. The lower number of genus and species in the cores is a result of the pollution of the current environment. 4. Conclusions In this study, the living habitat of benthic foraminifers were evaluated for radioactivity pollution in the Çanakkale Strait, which
Table 3 Core samples analysis results. Sample No
Radionuclides
Activity ± 2s (Bq/kg)
Measurable Lower Limit (Bq/kg)
International Average Limit Values (TAEK (2016))
Number of foraminifers (Yümün, 2016)
Seddülbahir
K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232
555.2 ± 62.0 5.7 ± 1.0 31.6 ± 3.1 29.3 ± 2.9 512.3 ± 72.1 2.0 ± 0.8 20.6 ± 2.8 24.0 ± 3.1 715.7 ±79.6 <2.0 48.6 ± 4.6 58.3 ± 5.5 725.6 ± 111.3 <6.0 47.4 ± 6.2 57.6 ± 7.2 443.7 ± 43.8 1.8 ± 0.3 16.9 ± 1.5 17.5 ± 1.6 698.1 ± 83.7 3.9 ± 1.1 30.7 ± 3.4 37.0 ± 4.0 510.3 ± 47.9 20.4 ± 1.8 20.8 ± 1.7 31.6 ± 2.5
13.40 1.20 2.84 2.25 35.10 1.98 4.54 3.18 19.80 1.98 2.85 1.95 46.30 6.01 5.96 7.14 5.34 0.46 1.04 0.89 18.40 2.35 3.68 3.17 3.84 0.48 0.79 0.62
400 e 35 30 400 e 35 30 400 e 35 30 400 e 35 30 400 e 35 30 400 e 35 30 400 e 35 30
45
Kumkale
Burhanlı
Eceabat
Gelibolu
S¸evketiye Lapseki
Çanakkale Dere Port
34
15
13
18
11
32
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Elphidium crispum, Elphidium complanatum, Lobatula lobatula, Lachnalle undulata, Massilina secans, Melonis pompilioides, Miliolinella subratunda, Quinqueloculina seminula.) were identified. In addition, in the drilling samples taken from the Çanakkale Strait, 13 foraminifera species and 20 genera (Adelosina cliarensis, Adelosina mediterranensis, Adelosina duthiersi, Ammonia compacta, Ammonia tepida, Ammonia parkinsoniana, Cribroelphidium poeyanum, Cycloforina contorta, Cycloforina villafranca, Brizalina spathulata, Elphidium complanatum, Elphidium crispum, Elphidium decipiens, Lobatula lobatula, Melonis pompilioides, Quinqueloculina seminula, Sigmoilinita costata, Spiroloculina excavata, Triloculina marioni, Textularia bocki) were identified (Yümün, 2016). The number of genus and species being lower in the cores is a result of the pollution in the current environment. Additionally, the number of foraminifera species and individuals obtained at locations with high pollution was very low compared to those in non-polluted zones. Acknowledgments
Fig. 2. Distribution of the activity concentration (Bq/kg).
constitutes the passage of the Marmara Sea and the Aegean Sea. Accordingly, seven core and one drilling sample were taken from the Çanakkale Strait in 2015. Locations of the core samples were specifically selected to be pollution indicators in port areas. The Gamma Spectrometric Analysis method was used to determine the radioactivity properties of sediments. The radionuclide concentration activity values in the sediment samples obtained from the locations were Cs-137 < 2e20 (Bq/kg), Th-232: 17.5e58.3 (Bq/ kg), Ra-226: 16.9e48.6 (Bq/kg), and K-40: 443.7e725.6 (Bq/kg). These values were compared with the Turkish Atomic Energy Agency (TAEK) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) data and environmental analysis was carried out. The Ra-226 series, the Th-232 series, and the K-40 radionuclides accumulate naturally and are continuously increasing due to anthropogenic pollution. Although the Ra-226 values obtained in the study areas remained within normal limits according to the UNSCEAR values, the K-40 and Th-232 series values were found to be high in almost all locations. The values of Cs-137 were found to be maximum 20 in Çanakkale Dere Port. These values were parallel to the values in the soils at the other locations. In the core samples taken from the Çanakkale Strait, 9 foraminifera species and 11 genera (Ammonia compacta, Ammonia parkinsoniana, Cycloforina villafranca,
The authors thank to Yümün Engineering Ltd., which financed the purchase of drilling and core samples in this study, Çekmece Nuclear Research Center for the analysis of radionuclides and the € authorities who performed the analyses, Melike Once and Sevinç Yümün for their contribution in the analysis of foraminifera. Authors also thank to reviewers for their suggestions. The authors also thank to Yıldız Technical University Scientific Research Projects Commission for accepting and financing this study (Project no: 2015-01-01-KAP01). References Artüz, L.M., 2007. Scientific Sea of Marmara. Turkish Bar Association Publications, 119 (/2) 1e290. Bozkurt, A., Yorulmaz, N., Kam, E., Karahan, G., Osmanlioglu, A.E., 2007. Assessment of environmental radioactivity for Sanliurfa region of Southeastern Turkey. Radiat. Meas. 42 (8), 1387e1391. € Güven, K.C., ve Oztürk, B., 2005. Sea Pollution. Istanbul University Institute of Marine Sciences and Management and Faculty of Fisheries. Publication Number: 21, 1e512 (In Turkish). Kam, E. (2016). http://www.turkbakis.com/turkiye/kafkaslarin-korkulu-ruyasimetsamor-h2484.html (Newspaper news). _ Kurt, D., Yümün, Z.U., Barut, I.F., Kam, E., 2016. Distribution of gamma radiation levels in core sediment samples in Gulf of Izmir: Eastern Aegean Sea. Int. J. Environ. Chem. Ecol. Geol. Geophys. Eng. 10 (3), 384e388. azı Toprak TAEK, 2016. Türkiye Atom Enerjisi Kurumu (TAEK) Çanakkale Bog erleri (In Turkish). http://www.taek.gov.tr. Radyonükleidleri Deg UNSCEAR, 2000. Sources and Effects of Ionizing Radiation. United Nations Scientific Committee on the Effects of Atomic Radiation. Report to General Assembly with Scientific Annexes (United Nations, New York). Yümün, Z.Ü., 2016. The effects of heavy metal concentrations in the Çanakkale Strait (Turkey): morphological differences in the holocene foraminiferal assemblages. J. Eng. Technol. Appl. Sci. 1 (2), 77e88.
Contents lists available at ScienceDirect
Journal of African Earth Sciences journal homepage: www.elsevier.com/locate/jafrearsci
Effects of radionuclides on the recent foraminifera from the clastic sediments of the Çanakkale Strait-Turkey Zeki Ünal Yümün a, *, Erol Kam b a b
, Turkey Namık Kemal University, Çorlu Engineering Faculty, Environmental Engineering Departmant, 59860 Çorlu, Tekirdag _ Yildiz Technical University, Faculty of Arts and Sciences, Physics Department, Davutpas¸a Campus, 34220 Esenler/ Istanbul, Turkey
a r t i c l e i n f o
a b s t r a c t
Article history: Received 4 February 2017 Received in revised form 15 April 2017 Accepted 19 April 2017 Available online 22 April 2017
The radionuclides that cause radioactivity accumulate in the sediments as they descend to the seabed, similar to heavy metals. As radionuclides are present on the surface of the sediment or within the sediment, marine benthic foraminifera can be affected by the radioactive pollution. In this study, the habitat of benthic foraminifera was evaluated for radioactive pollution in the Çanakkale Strait, which constitutes the passage of the Marmara Sea and the Aegean Sea. In 2015, seven core samples and one drilling sample were taken from the shallow marine environment, which is the habitat of benthic foraminifera, in the Çanakkale Strait. Locations of the core samples were specifically selected to be pollution indicators in port areas. Gamma spectrometric analysis was used to determine the radioactivity properties of sediments. The radionuclide concentration activity values in the sediment samples obtained from the locations were Cs-137: <2e20 (Bq/kg), Th-232: 17.5 e58.3 (Bq/kg), Ra-226: 16.9e48.6 (Bq/kg) and K-40: 443.7e725.6 (Bq/kg). These values were compared with the Turkish Atomic Energy Agency (TAEK) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) data and environmental analysis was carried out. The Ra-226 series, the Th-232 series and the K-40 radionuclides accumulate naturally and increase continuously due to anthropogenic pollution. Although the Ra-226 values obtained in the study areas remained within normal limits according to UNSCEAR values, the K-40 and Th-232 series values were observed to be high in almost all locations. The values of Cs-137 were found to be maximum 20 in Çanakkale Dere Port and they were parallel to the values in the other places. In the study, 13 genera and 20 species were identified from core and drilling samples. The number of foraminifera species and individuals obtained at locations with high pollution was very low compared to those in non-polluted zones. © 2017 Elsevier Ltd. All rights reserved.
Keywords: Ra-226 Th-232 K-40 Cs-137 Radionuclide Foraminifera Çanakkale Strait
1. Introduction Throughout the world, technological developments can cause radioactive pollution that results from industrial and nuclear waste. Furthermore, radioactive elements with very long lives that occur naturally in the Earth's crust also form a natural radiation level. Every living creature on the Earth is continuously exposed to radioactive substances that are formed by both natural radiation and human activities. Radioactive pollutants entering the marine environments through dry and wet precipitation are also carried to
* Corresponding author. E-mail addresses: [email protected] (Z. Yümün), [email protected] (E. Kam). http://dx.doi.org/10.1016/j.jafrearsci.2017.04.018 1464-343X/© 2017 Elsevier Ltd. All rights reserved.
the sea by streams. As seen in the Chernobyl disaster, transport of contaminated soils to the sea by erosion also contaminates these environments. Water contaminated with radioactive pollutants that is entering the marine environment is circulated between the € sediment and the organisms (Güven and Oztürk, 2005). Benthic foraminifera will be affected by radioactive contamination in marine sediments, especially as they live in sediments on the seabed. Therefore, the habitats of foraminifera were evaluated as pollution indicators in marine environments. Natural radionuclides such as the 238 U series, 232 Th series and 40 K exist in various levels in the soil, sediment, water, plants, and air. The natural radionuclide distribution depends on the geological and geographical conditions of each region (Kurt et al., 2016). Cs-137, one of the artificial radionuclides, has high water solubility and it can move easily. In the ecological environment, the
180
Z. Yümün, E. Kam / Journal of African Earth Sciences 131 (2017) 179e182
presence of Cs-137 indicates nuclear weapons tests or fallout. After the nuclear accidents in 1986, Chernobyl and in 2011, Fukushima, artificial radionuclides such as Cs-137 have mixed with the receiving mediums (e.g., sea, rivers, air, and soil) and have been very quickly transported kilometers from their sources. In particular, nuclear power plants that have been installed in earthquakeprone areas have the potential to be either completely destroyed or damaged by earthquake, causing leaks (e.g., Metsamor Nuclear Power Plant in Armenia) and posing a great threat to worldwide living conditions (Kam, 2016). In this study, natural and artificial radionuclide distributions were investigated by using gamma spectrometry in core sediment samples and drilling samples taken from different points in the Çanakkale Strait. Table 1 shows the values of the radionuclides determined around the Çanakkale Strait in the distribution chart of soil and water radioactivity of the Turkish Atomic Energy Agency. The values given in Table 1 were compared with the radionuclide values obtained in this study and the basis of the high values in the sea € were investigated (Güven and Oztürk, 2005).
Table 2 Core sample coordinates. Sample code
1-Burhanli (Çanakkale) 2-Dereliman (Çanakkale) 3-Eceabat (Çanakkale) 4-Gelibolu (Çanakkale) 5-Kumkale (Çanakkale) 6-Lapseki (Çanakkale) 7-Seddülbahir (Çanakkale) 8-S¸evketiye (Lapseki)
Sample Amount (L)
2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
Coordinates (UTM, 6 Degree) (Y)
(X)
463,791 449,212 445,495 471,306 436,965 473,852 430,862 489,498
4,463,231 4,443,871 4,448,541 4,478,121 4,428,080 4,466,935 4,432,732 4,471,929
2. Materials and methods In this study, one drilling sample was taken from the Çanakkale Strait (BH-7) and eight core samples were taken from eight different locations (Burhanlı, Dereliman, Eceabat, Gelibolu, Kumkale, Lapseki, Seddülbahir, and S¸evketiye) (Table 2 and Fig. 1). Samples were collected with the YUMUN 01 drilling platform. Attention was paid to the existing pollution conditions while taking the core samples and drilling sample. The drilling samples were taken with the drilling platform installed on the sea with the rotary drilling system. However, the core samples were taken by hydraulic pressure method. The cores and drilling cores were divided into 10 cm sections from top to bottom and samples were prepared for foraminifera analysis. Each sample was kept in a 10% H2O2 solution for 24 h, then filtered through a 125 mm to remove the foraminifera. Segregation was carried out using a stereozoom microscope and systematic descriptions of each foraminifera were made. For radionuclide analysis, samples were first prepared for radioactive analysis by keeping them at room temperature in a laboratory environment. Analyses of the prepared samples were performed in the Çekmece Radioactivity and Analytical Measurement Department. The samples were finely powdered by filtering through a 100-mm sieve. The powdered samples were placed in 1000 mL Marinelli test bottles and bottle openings were sealed to prevent air contact. The samples were kept for 40 days after weighing to equilibrate between radium, thorium and other degradation products. Gamma spectrometry analysis (Canberra GX5020) was used with an HPGe detector, which was joined to a coaxial high-purity germanium (Bozkurt et al., 2007). The setup was calibrated by using solid, diverse gamma emitting reference sources in a 1 L Marinelli beaker. The gamma activity relied on 238U series, 609.3 keV; 232Th series, 583 keV; 228Ac, 911.2 keV; 226Ra, 185.7 keV; 137Cs, 661.7 keV; 40 K, 1460,8 keV (UNSCEAR, 2000).
Table 1 Turkey atomic energy agency soil radionuclide values in Çanakkale Strait (Güven and € Oztürk, 2005). Radionuclides
Low (Bq/kg)
High (Bq/kg)
Th-232 Ra-226 K-40 Cs-137
5.00 10.10 50.00 0.00
50.10 75.00 100.00 20.00
Fig. 1. Location map of eight points where core samples and Bore Hole Samples (BH-7) were taken at Çanakkale Strait.
3. Results and discussion 3.1. Geological setting of investigation area The investigated area is the Çanakkale Strait, which constitutes the passage of the Marmara Sea which is part of the strait system connecting the Black Sea and the Mediterranean (Fig. 1). Between the Gallipoli and Biga peninsulas, the Çanakkale Strait is 61 km long, between 12 and 6 km wide, and has a maximum depth of 82 m and an average depth of 55 m (Artüz, 2007). From the geological and morphological point of view, the Çanakkale Strait has undergone quite a complex evolution. Geologically, the Çanakkale Strait extends along the deepest point of a depression formed by Neogene-aged sediments. Both basins of the Çanakkale Strait, the main and Neogene covers, were cut by an Upper Pliocene age abrasion surface descending toward the strait axis. The Strait was formed on the depressions that formed this abrasion surface and later sank with its branches and acquired its current form. The Çanakkale Strait and neighboring area, which was an important settlement in ancient times, also have strategic importance due to its geopolitical position. Surrounded by the Çanakkale Province, the economic activities of the strait are mostly agricultural. Industry and trade have also developed as a result of these agricultural activities.
Z. Yümün, E. Kam / Journal of African Earth Sciences 131 (2017) 179e182
3.2. Radionuclides of sediments in investigation area
181
Table 4 Drilling (BH-7) samples analysis results.
The radionuclide concentration activity values in the sediment samples obtained from the locations were Cs-137 < 2e20 (Bq/kg), Th-232: 17.5e58.3 (Bq/kg), Ra-226: 16.9e48.6 (Bq/kg), and K40 ¼ 443.7e725.6 (Bq/kg). The activity values of the radionuclides of the core benthic foraminifera samples are given in Table 3 and the values of the drilling samples (Bore Hole-7: BH-7) are given in Table 4. These values were compared with the international average values (Table 5). In core samples, K-40 was higher than the world limit values at all locations, Th-232 was below the limit value at three locations and above at four locations, and Ra-226 was below the limit value at five locations and above at two locations. Radionuclides are atoms that have excess nuclear energy, making their unstable. In the samples collected from the upper, middle and lower locations of the drilling, the values of activity for K-40 and Th-232 for the samples taken from the upper and lower locations were above the limit value and below the limit value at the middle locations compared with the international average limit values. R-226 radionuclide was just below the limit at the lower locations of the drilling and below the limit value at the upper and middle locations. Sediment samples have different physical, chemical, geological form and location characteristics; therefore, the obtained numerical results vary. The region's economy has developed based on agriculture, and the industrial facilities use agricultural raw materials. This has increased the use of fertilizers in agricultural activities. The use of potassium-rich fertilizers has enriched the potassium content of the soil. The transport of potassium-rich soils to the sea by erosion appears to increase the radioactivity of the habitat (Table 1). It also suggests that K-40 has the highest absorption activity, as it is high in all regions. Fig. 2 shows the distribution of radionuclides for the seven sample locations in the Çanakkale Strait.
Sample
Radionuclides
Activity ± 2s (Bq/kg)
Measurable Lower Limit (Bq/kg)
BH-7/12 m
K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232
558.0 ± 83.4 10.9 ± 2.3 19.1 ± 2.9 30.1 ± 4.0 380.9 ± 47.3 3.0 ± 0.8 14.3 ± 1.8 13.6 ± 1.7 709.4 ± 68.1 <1.0 46.6 ± 3.7 53.1 ± 4.3
37.50 2.37 4.60 3.81 13.10 1.51 2.49 1.99 5.07 1.03 1.35 1.21
BH-7/18 m
BH-7/23 m
Table 5 International average values (UNSCEAR, 2000). Radionuclides
International Average Limit Values
Th-232 Ra-226 K-40
30 Bq kg1 35 Bq kg1 400 Bq kg1
Numerous foraminifera genus and species were identified from core samples. Nine foraminiferal genus and 11 species were obtained in the core samples, while 13 genera and 20 species were obtained in the drilling samples. The lower number of genus and species in the cores is a result of the pollution of the current environment. 4. Conclusions In this study, the living habitat of benthic foraminifers were evaluated for radioactivity pollution in the Çanakkale Strait, which
Table 3 Core samples analysis results. Sample No
Radionuclides
Activity ± 2s (Bq/kg)
Measurable Lower Limit (Bq/kg)
International Average Limit Values (TAEK (2016))
Number of foraminifers (Yümün, 2016)
Seddülbahir
K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232 K-40 Cs-137 Ra-226 Th-232
555.2 ± 62.0 5.7 ± 1.0 31.6 ± 3.1 29.3 ± 2.9 512.3 ± 72.1 2.0 ± 0.8 20.6 ± 2.8 24.0 ± 3.1 715.7 ±79.6 <2.0 48.6 ± 4.6 58.3 ± 5.5 725.6 ± 111.3 <6.0 47.4 ± 6.2 57.6 ± 7.2 443.7 ± 43.8 1.8 ± 0.3 16.9 ± 1.5 17.5 ± 1.6 698.1 ± 83.7 3.9 ± 1.1 30.7 ± 3.4 37.0 ± 4.0 510.3 ± 47.9 20.4 ± 1.8 20.8 ± 1.7 31.6 ± 2.5
13.40 1.20 2.84 2.25 35.10 1.98 4.54 3.18 19.80 1.98 2.85 1.95 46.30 6.01 5.96 7.14 5.34 0.46 1.04 0.89 18.40 2.35 3.68 3.17 3.84 0.48 0.79 0.62
400 e 35 30 400 e 35 30 400 e 35 30 400 e 35 30 400 e 35 30 400 e 35 30 400 e 35 30
45
Kumkale
Burhanlı
Eceabat
Gelibolu
S¸evketiye Lapseki
Çanakkale Dere Port
34
15
13
18
11
32
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Z. Yümün, E. Kam / Journal of African Earth Sciences 131 (2017) 179e182
Elphidium crispum, Elphidium complanatum, Lobatula lobatula, Lachnalle undulata, Massilina secans, Melonis pompilioides, Miliolinella subratunda, Quinqueloculina seminula.) were identified. In addition, in the drilling samples taken from the Çanakkale Strait, 13 foraminifera species and 20 genera (Adelosina cliarensis, Adelosina mediterranensis, Adelosina duthiersi, Ammonia compacta, Ammonia tepida, Ammonia parkinsoniana, Cribroelphidium poeyanum, Cycloforina contorta, Cycloforina villafranca, Brizalina spathulata, Elphidium complanatum, Elphidium crispum, Elphidium decipiens, Lobatula lobatula, Melonis pompilioides, Quinqueloculina seminula, Sigmoilinita costata, Spiroloculina excavata, Triloculina marioni, Textularia bocki) were identified (Yümün, 2016). The number of genus and species being lower in the cores is a result of the pollution in the current environment. Additionally, the number of foraminifera species and individuals obtained at locations with high pollution was very low compared to those in non-polluted zones. Acknowledgments
Fig. 2. Distribution of the activity concentration (Bq/kg).
constitutes the passage of the Marmara Sea and the Aegean Sea. Accordingly, seven core and one drilling sample were taken from the Çanakkale Strait in 2015. Locations of the core samples were specifically selected to be pollution indicators in port areas. The Gamma Spectrometric Analysis method was used to determine the radioactivity properties of sediments. The radionuclide concentration activity values in the sediment samples obtained from the locations were Cs-137 < 2e20 (Bq/kg), Th-232: 17.5e58.3 (Bq/ kg), Ra-226: 16.9e48.6 (Bq/kg), and K-40: 443.7e725.6 (Bq/kg). These values were compared with the Turkish Atomic Energy Agency (TAEK) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) data and environmental analysis was carried out. The Ra-226 series, the Th-232 series, and the K-40 radionuclides accumulate naturally and are continuously increasing due to anthropogenic pollution. Although the Ra-226 values obtained in the study areas remained within normal limits according to the UNSCEAR values, the K-40 and Th-232 series values were found to be high in almost all locations. The values of Cs-137 were found to be maximum 20 in Çanakkale Dere Port. These values were parallel to the values in the soils at the other locations. In the core samples taken from the Çanakkale Strait, 9 foraminifera species and 11 genera (Ammonia compacta, Ammonia parkinsoniana, Cycloforina villafranca,
The authors thank to Yümün Engineering Ltd., which financed the purchase of drilling and core samples in this study, Çekmece Nuclear Research Center for the analysis of radionuclides and the € authorities who performed the analyses, Melike Once and Sevinç Yümün for their contribution in the analysis of foraminifera. Authors also thank to reviewers for their suggestions. The authors also thank to Yıldız Technical University Scientific Research Projects Commission for accepting and financing this study (Project no: 2015-01-01-KAP01). References Artüz, L.M., 2007. Scientific Sea of Marmara. Turkish Bar Association Publications, 119 (/2) 1e290. Bozkurt, A., Yorulmaz, N., Kam, E., Karahan, G., Osmanlioglu, A.E., 2007. Assessment of environmental radioactivity for Sanliurfa region of Southeastern Turkey. Radiat. Meas. 42 (8), 1387e1391. € Güven, K.C., ve Oztürk, B., 2005. Sea Pollution. Istanbul University Institute of Marine Sciences and Management and Faculty of Fisheries. Publication Number: 21, 1e512 (In Turkish). Kam, E. (2016). http://www.turkbakis.com/turkiye/kafkaslarin-korkulu-ruyasimetsamor-h2484.html (Newspaper news). _ Kurt, D., Yümün, Z.U., Barut, I.F., Kam, E., 2016. Distribution of gamma radiation levels in core sediment samples in Gulf of Izmir: Eastern Aegean Sea. Int. J. Environ. Chem. Ecol. Geol. Geophys. Eng. 10 (3), 384e388. azı Toprak TAEK, 2016. Türkiye Atom Enerjisi Kurumu (TAEK) Çanakkale Bog erleri (In Turkish). http://www.taek.gov.tr. Radyonükleidleri Deg UNSCEAR, 2000. Sources and Effects of Ionizing Radiation. United Nations Scientific Committee on the Effects of Atomic Radiation. Report to General Assembly with Scientific Annexes (United Nations, New York). Yümün, Z.Ü., 2016. The effects of heavy metal concentrations in the Çanakkale Strait (Turkey): morphological differences in the holocene foraminiferal assemblages. J. Eng. Technol. Appl. Sci. 1 (2), 77e88.