Ядерна фізика та енергетика Nuclear Physics and Atomic Energy   ISSN: 1818-331X (Print), 2074-0565 (Online)   Publisher: Institute for Nuclear Research of the National Academy of Sciences of Ukraine   Languages: Ukrainian, English   Periodicity: 4 times per year   Open access peer reviewed journal

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V. O. Kashparov^1,*, S. Ye. Levchuk¹, D. M. Holiaka¹, Yu. V. Khomutinin¹, V. P. Protsak¹, D. M. Kondratiuk², M. A. Zhurba<sup>1

1</sup> Ukrainian Institute of Agricultural Radiology, National University of Life and Environmental Sciences of Ukraine, Kyiv, Ukraine
² Drevlianskyi Nature Reserve, Narodychi, Ukraine

^*Corresponding author. E-mail address: kashparov@nubip.edu.ua

Abstract: After the accidents at the Chornobyl NPP in 1986 and the Fukushima-1 NPP in 2011, the specific activity of radionuclides in fish in radioactively contaminated freshwater bodies reached hundreds of kBq kg^-1 and exceeded international and national permissible levels. The work aimed to determine the content of radionuclides in different fish species in "the semi-closed" flooding Starukha Lake, which is located in the north-western trace of radioactive fallout in the Chornobyl Exclusion Zone (ChEZ). The experimental studies were conducted during 2000 - 2018. The values of ¹³⁷Cs and ⁹⁰Sr specific activities in different fish species were obtained. The maximum levels of ¹³⁷Cs specific activity in fish muscle tissue of 3.7 and 3.6 kBq·kg^-1 were in pikes, which weighed 6.2 and 1.65 kg and were caught on 04.10.2000 and 30.08.2006, respectively. In 2016 and 2018, the specific activity of ¹³⁷Cs in muscle tissue and ⁹⁰Sr in bone tissue did not exceed 800 Bq·kg^-1. The effective half-lives of ¹³⁷Cs specific activities in muscle tissue of pike, pike perch, and common whitefish were estimated to be in the range of 19 - 30 years. The radioactive decay of the radionuclide is the main process governing the activity decreasing. The geometric mean of ¹³⁷Cs specific activity in the muscle tissue of pike, pike perch, and whitefish in Starukha Lake will decrease below the permissible level of 150 Bq kg^-1 by 2043 - 2072. At the same time, the non-exceeding specific activity of ¹³⁷Cs in the muscle tissue of individual fish with a probability of 95 % will be achieved in 50 - 100 years. Thus, there is a potential threat that fish may migrate during flooding from "semi-closed" lakes in the ChEZ to the Pripyat River and the Kyiv Reservoir.

Keywords: ⁹⁰Sr, ¹³⁷Сs, radioecology, Chornobyl accident, Exclusion Zone, radioactive contamination.

1. Permissible levels of radionuclides ¹³⁷Cs and ⁹⁰Sr in food and drinking water (DR-2006). Hygienic standard of the State Sanitary and Epidemiological Service. HS 6.6.1.1 130 2006. (Ukr) http://search.ligazakon.ua/l_doc2.nsf/link1/RE12719.html

2. Handbook of Parameter Values for the Prediction of Radionuclide Transfer in Terrestrial and Freshwater Environments. Technical reports series No. 472 (Vienna, IAEA, 2010) 208 p. http://www-pub.iaea.org/MTCD/Publications/PDF/trs472_web.pdf

3. A.Ye. Kaglyan et al. Dynamics of specific activity of ⁹⁰Sr and ¹³⁷Cs in representatives of ichthyofauna of Chornobyl exclusion zone. Nucl. Phys. At. Energy 22(1) (2021) 62. (Ukr) https://doi.org/10.15407/jnpae2021.01.062

4. A.Ye. Kaglyan et al. The absorbed dose rate of external exposure to representatives of ichthyofauna of lakes in the Chornobyl exclusion zone. Nucl. Phys. At. Energy 25(2) (2024) 141. (Ukr) https://doi.org/10.15407/jnpae2024.02.141

5. H.-C. Teien et al. Seasonal changes in uptake and depuration of ¹³⁷Cs and ⁹⁰Sr in silver Prussian carp (Carassius gibelio) and common rudd (Scardinius erythrophthalmus). Sci. Total Environ. 786 (2021) 147280. https://doi.org/10.1016/j.scitotenv.2021.147280

6. M. Hrechaniuk et al. Radioactive contamination and doses of internal irradiation of fish in the Deep lake of the Chornobyl exclusion zone. Sci. Rep. Natl. Univ. Life Environ. Sci. Ukr. 3(97) (2022). (Ukr) http://dx.doi.org/10.31548/dopovidi2022.03.003

7. O. Kashparova et al. Clean feed as countermeasure to reduce the ⁹⁰Sr and ¹³⁷Cs levels in fish from contaminated lakes. J. Environ. Radioact. 258 (2023) 107091. https://doi.org/10.1016/j.jenvrad.2022.107091

8. P. Pavlenko et al. Testing countermeasures to reduce ⁹⁰Sr content in fish products. J. Environ. Radioact. 271 (2024) 107316. https://doi.org/10.1016/j.jenvrad.2023.107316

9. Yu.V. Khomutinin, V.A. Kashparov, A.V. Kuz'menko. Dependences of ¹³⁷Cs and ⁹⁰Sr concentration ratios in fish on the potassium and calcium concentrations in the freshwater reservoirs. Radiats. Biol. Radioecol. 51(3) (2011) 374. (Rus) https://pubmed.ncbi.nlm.nih.gov/21866838/

10. Environmental Consequences of the Chernobyl Accident and their Remediation: Twenty Years of Experience. Report of the Chernobyl Forum Expert Group 'Environment'. Radiological Assessment Reports Series (Vienna, IAEA, 2006) 180 p. http://www-pub.iaea.org/MTCD/Publications/PDF/Pub1239_web.pdf

11. I.G. Travnikova et al. Lake fish as the main contributor of internal dose to lakeshore residents in the Chernobyl contaminated area. J. Environ. Radioact. 77(1) (2004) 63. https://doi.org/10.1016/j.jenvrad.2004.03.003

12. V. Kashparov et al. Spatial datasets of radionuclide contamination in the Ukrainian Chernobyl Exclusion Zone. Earth Syst. Sci. Data 10 (2018) 339. https://doi.org/10.5194/essd-10-339-2018

13. V. Kashparov et al. Spatial radionuclide deposition data from the 60 km radial area around the Chernobyl Nuclear Power Plant: results from a sampling survey in 1987. Earth Syst. Sci. Data 12 (2020) 1861. https://doi.org/10.5194/essd-12-1861-2020

14. Yu.V. Khomutinin et al. Forecast of the dynamics and risk of exceeding the permissible content of ¹³⁷Cs and ⁹⁰Sr in fish of the Kyiv reservoir in the late phase of the Chornobyl accident. Radiats. Biol. Radioecol. 53(4) (2013) 411. (Rus) http://dx.doi.org/10.7868/S0869803113040103

15. Yu.V. Khomutinin. Evaluation of radioecological safety of freshwater reservoirs in Ukraine during late phase of ChNPP accident. Nucl. Phys. At. Energy 15(4) (2014) 389. (Ukr) https://doi.org/10.15407/jnpae2014.04.389

16. Yu.V. Khomutinin, V.O. Kashparov. Optimization of fish sampling procedure for evaluating the specific activity of ¹³⁷Cs, ⁹⁰Sr and accumulation coefficients. Nucl. Phys. At. Energy 17(2) (2016) 189. (Rus) https://doi.org/10.15407/jnpae2016.02.189

17. V. Kashparov et al. Uptake from water and depuration of ¹³⁷Cs and ⁹⁰Sr by silver Prussian carp (Carassius gibelio). J. Environ. Radioact. 276 (2024) 107443. https://doi.org/10.1016/j.jenvrad.2024.107443

18. Report on the research work "Study of the patterns of behavior of radionuclides and other heavy metals in aquatic ecosystems in the territories contaminated as a result of the Chernobyl disaster", No. 0106U004248 (Kyiv, National University of Life and Environmental Sciences of Ukraine, 2008) 91 p. (Ukr)

19. F.I. Pavlotskaya. Basic principles of radiochemical analysis of environmental objects and methods for determination of strontium radionuclides and transuranic elements. J. Anal. Chem. 52(2) (1997) 126. (Rus)

20. С. Glantz. Medico-Biological Statistics (Moscow: Praktika, 1998) 459 p. (Rus)

21. https://fisher-club.com/news/spravka/1-0-9

22. T.L. Yankovich et al. Whole-body to tissue concentration ratios for use in biota dose assessments for animals. Radiat. Environ. Biophys. 49 (2010) 549. https://doi.org/10.1007/s00411-010-0323-z