Measurement of Natural Radioactivity Levels and Evaluation of Radiological Hazard Risks in Areas of Eastern Coastline Sediments of Lake Hawassa in Ethiopia’s Sidama Region

Document Type : Original Research Paper


Department of Physics, Addis Ababa University, Arat Kilo Campus, Fax: +251-111-239768, P.O.Box: 1176, Addis Ababa, Ethiopia


Natural radioactivity levels in the eastern coastline of Lake Hawassa sediment samples of Ethiopia’s Sidama Region have been measured. Sediment samples were collected and analyzed using gamma-ray spectrometery (high purity germanium detector) to evaluate the radioisotopes of 238U (214Pb, 214Bi), 232Th (228Ac, 212Pb), and 40K and their ranges of activity concentrations were 11.70 to 29.73 Bq 〖kg〗^(-1), 19.01 to 58.61 Bq 〖kg〗^(-1), and BDL to 827.21 Bq 〖kg〗^(-1) ,with average values of 16.51 ± 1.20 Bq 〖kg〗^(-1) , 28.17 ± 2.27 Bq 〖kg〗^(-1) ,and 673.95 ± 29.92 Bq 〖kg〗^(-1) (dry mass), respectively. The radiological hazard indices average values (radium equivalent (R_eq) (108.69 Bq 〖kg〗^(-1) ); hazard index (H_ex (0.29); excess lifetime cancer risk (ELCR) (0.23 x 〖10〗^(-3) ); absorbed dose rate (D_R) (52.70 nGyh^(-1) ); annual effective dose equivalent (AEDE) (0.07 mSv〖yr〗^(-1)); and annual gonadal dose equivalent (AGDE) (0.38 mSv〖yr〗^(-1)) were also evaluated and compared to the worldwide-recommended values. All results of radiological hazard indices obtained in this study were lower than their worldwide-recommended values were 370 Bq 〖kg〗^(-1), ≤1, 59 nGyh^(-1), 0.07mSv〖yr〗^(-1), 0.29 × 〖10〗^(-3), and 0.3mSv〖yr〗^(-1) of radium equivalent activity, external hazard index, outdoor absorbed dose rate, outdoor annual effective dose equivalent, excess lifetime cancer risk, and annual gonadal dose equivalent, respectively. This suggests the eastern coastline of Lake Hawassa is safe from radioactive risk for aquatic species and various human activities, and appears as essential radiometric baseline information for further environmental monitoring programs.


Main Subjects

Beretka, J., & Mathew, P. J. (1985). Natural radioactivity of australian building materials, industrial wastes and by-products. Health Phys., 48(1), 87-95.
Botwe, B. O., Schirone, A., Delbono, I., Barsanti, M., Delfanti, R., Kelderman, P., . . . Lens, P. N. (2016). Radioactivity concentrations and their radiological significance in sediments of the Tema Harbour (Greater Accra, Ghana). J. Radiat. Res. Appl. Sci., 10(1), 63-71.
Chowdhury, M. I., Alam, M. N., & Hazari, S. K. (1999). Distribution of radionuclides in the river sediments and coastal soils of Chittagong, Bangladesh and evaluation of the radiation hazard. Appl. Radiat. Isot., 51(6), 747-755.
Da Silva, C. M., & Da Silva Filho, C. A. (2019). Natural radionuclides in water and sediments of the São Francisco River in Petrolina, Brazil. Int. J. Low Radiat., 11(2), 89.
Darko, G., Ansah, E., Faanu, A., & Azanu, D. (2017). Natural radioactivity and heavy metal distribution in reservoirs in Ghana. Pollution, 3(2), 225-241. 006.
Darwish, D., Abul-Nasr, K., & El-Khayatt, A. (2015). The assessment of natural radioactivity and its associated radiological hazards and dose parameters in granite samples from South Sinai, Egypt. J. Radiat. Res. Appl. Sci., 8(1), 17-25.
El Mamoney, M. H., & Khater, A. E. (2004). Environmental characterization and radio-ecological impacts of non-nuclear industries on the Red Sea coast. J. Environ. Radioact., 73(2), 151-168.
El-Gamal, A., Nasr, S., & El-Taher, A. (2007). Study of the spatial distribution of natural radioactivity in the upper Egypt Nile River sediments. Radiat.Meas., 42(3), 457-465.
Erenturk, S., Yusan, S., Turkozu, D. A., Camtakan, Z., Olgen, M. K., Aslani, M. A., . . . Isik, M. A. (2014). Spatial distribution and risk assessment of radioactivity and heavy metal levels of sediment, surface water and fish samples from Lake Van, Turkey. J. Radioanal. Nucl. Chem., 300(3), 919-931.
Eroǧlu, H., & Kabadayi, Ö. (2013). Natural radioactivity levels in lake sediment samples. Radiat. Prot. Dosim., 156(3), 331-335.
Fares, S. (2017). Measurements of natural radioactivity level in black sand and sediment samples of the Temsah Lake beach in Suez Canal region in Egypt. J. Radiat. Res. Appl. Sci., 10(3), 194-203.
Hameed, P. S., Pillai, G. S., Satheeshkumar, G., & Mathiyarasu, R. (2014). Measurement of gamma radiation from rocks used as building material in Tiruchirappalli district, Tamil Nadu, India. J. Radioanal. Nucl. Chem., 300(3), 1081-1088.
Ibrahim, M. N., Shawkay, S., & Amer, H. (1995). Radioactivity levels in lake Nasser sediments. Appl. Radiat. Isot., 46(5), 297-299.
ICRP. (1990). The 1990 Recommendations of the International Commission on Radiological Protection.Oxford,UK: ICRP Publication 60. Annals of the ICRP. 21(1-3).
ICRP, .. (2007). The 2007 Recommendations of the International Commission on Radiological Protection:Annals of the ICRP publication 103. 37(2-4).
ICRP. (2008). Radiation Dose to Patients from Radiopharmaceuticals.Addendum 3 to ICRP Publication 53.ICRP Publication 106. 38(1-2).
Isinkaye, M., & Emelue, H. (2015). Natural radioactivity measurements and evaluation of radiological hazards in sediment of Oguta Lake, South East Nigeria. J. Radiat. Res. Appl. Sci., 8(3), 459-469.
Jibiri, N. N., & Okeyode, I. C. (2012). Evaluation of radiological hazards in the sediments of Ogun river, South-Western Nigeria. Radiat. Phys. Chem. , 81(2), 103-112.
Jibiri, N., & Okeyode, I. (2011). Activity concentrations of natural radionuclides in the sediments of Ogun River, southwestern Nigeria. Radiat.Prot.Dosim., 147(4), 555-564.
Karahan, G., & Bayulken, A. (2000). Assessment of gamma dose rates around Istanbul (Turkey). J. Environ. Radioact., 47(2), 213-221.
Khater, A. E., Ebaid, Y. Y., & El-Mongy, S. A. (2005). Distribution pattern of natural radionuclides in Lake Nasser bottom sediments. Int. congr. ser., 1276, 405-406.
Kobya, Y., Taşkın, H., Yeşilkanat, C. M., Varinlioğlu, A., & Korcak, S. (2015). Natural and artificial radioactivity assessment of dam lakes sediments in Çoruh River, Turkey. J. Radioanal. Nucl. Chem., 303(1), 287-295.
Kurnaz, A., Küçükömeroǧlu, B., Keser, R., Okumusoglu, N. T., Korkmaz, F., Karahan, G., & Çevik, U. (2007). Determination of radioactivity levels and hazards of soil and sediment samples in Fi{dotless}rti{dotless}na Valley (Rize, Turkey). Appl. Radiat. Isot., 65(11), 1281-1289.
Lu, X., Zhang, X., & Wang, F. (2008). Natural radioactivity in sediment of Wei River, China. Environ. Geol., 53(7), 1475-1481.
Menberu, Z., Mogesse, B., & Reddythota, D. (2021). Regional Studies Assessment of morphometric changes in Lake Hawassa by using surface and bathymetric maps. J. Hydrol. Reg. Stud., 36(June), 100852.
Morsy, Z., El-Wahab, M. A., & El-Faramawy, N. (2012). Determination of natural radioactive elements in Abo Zaabal, Egypt by means of gamma spectroscopy. Ann. Nucl. Energy, 44(September 2020), 8-11.
Mulugeta, D. B., David, H.-C., Ruth E., M., & Cryton, Z. (2021). Building foundations for source-to-sea management: the case of sediment management in the Lake Hawassa sub-basin of the Ethiopian Rift Valley. Water Int., 46(2), 138-156.
Murugesan, S., Mullainathan, S., Ramasamy, V., & Meenakshisundaram, V. (2011). Radioactivity and radiation hazard assessment of Cauvery River, Tamilnadu, India. Iran. J. Radiat. Res, 8(4), 211-222.
Murugesan.S, Mullainathan.S, & Ramasamy.V. (2015). Natural radioactivity and hazardous index of major South Indian river sediments. Int. J. Low Radiat., 10(1), 14-33.
Onjefu, A. S., Taole H., S., Kgabi A., N., Grant, C., & Antoine, J. (2017). Assessment of natural radionuclide distribution in shore sediment samples collected from the North Dune beach, Henties Bay, Namibia. J. Radiat. Res. Appl. Sci., 10(4), 301-306.
Orgun, Y., Altınsoy, N., Sahin, S., Gungor, Y., Gultekin, A., Karahan, G., & Karacık, Z. (2007). Natural and anthropogenic radionuclides in rocks and beach sands from Ezine region (C- anakkale), Western Anatolia, Turkey. Appl.Radiat.Isot., 65, 739-747.
Powell, B. A., Hughes, L. D., Soreefan, A. M., Falta, D., Wall, M., & Devol, T. A. (2007). Elevated concentrations of primordial radionuclides in sediments from the Reedy River and surrounding creeks in Simpsonville , South Carolina. J. Environ. Radioact., 94, 121-128.
Qureshi, A. A., Tariq, S., Din, K. U., Manzoor, S., Calligaris, C., & Waheed, A. (2014). Evaluation of excessive lifetime cancer risk due to natural radioactivity in the rivers sediments of Northern Pakistan. J. Radiat. Res. Appl. Sci., 7(4), 438-447.
Ramasamy, V., Sundarrajan, M., Suresh, G., Paramasivam, K., & Meenakshisundaram, V. (2014). Role of light and heavy minerals on natural radioactivity level of high background radiation area, Kerala, India. Appl.Radiat.Isot., 85, 1-10.
Ramasamy, V., Suresh, G., Meenakshisundaram, V., & Ponnusamy, V. (2011). Horizontal and vertical characterization of radionuclides and minerals in river sediments. Appl.Radiat.Isot., 69(1), 184-195.
Ravisankar, R., Sivakumar, S., Chandrasekaran, A., Prince Prakash Jebakumar, J., Vijayalakshmi, I., Vijayagopal, P., & Venkatraman, B. (2014). Spatial distribution of gamma radioactivity levels and radiological hazard indices in the East Coastal sediments of Tamilnadu, India with statistical approach. Radiat. Phys. Chem., 103, 89-98.
Semaria Moga, L., Jens, T., & Mihret, D. (2021). Assessing the Water Quality of Lake Hawassa Ethiopia-Trophic State and Suitability for Anthropogenic Uses-Applying Common Water Quality Indices Assessing the Water Quality of Lake Hawassa Ethiopia — Trophic State and Suitability for Anthropogenic Uses. Int. J. Environ. Res. Public Health, 18(August), 8904.
Shetty, P., & Narayana, Y. (2010). Variation of radiation level and radionuclide enrichment in high background area. J.Environ.Radioact., 101(12), 1043-1047.
Suresh, G., Ramasamy, V., Meenakshisundaram, V., Venkatachalapathy, R., & Ponnusamy, V. (2011). A relationship between the natural radioactivity and mineralogical composition of the Ponnaiyar river sediments, India. J.Environ.Radioact., 102(4), 370-377.
SureshGandhi, M., Ravisankar, R., Rajalakshmi, A., Sivakumar, S., Chandrasekaran, A., & Pream Anand, D. (2014). Measurements of natural gamma radiation in beach sediments of north east coast of Tamilnadu, India by gamma ray spectrometry with multivariate statistical approach. J. Radiat. Res. Appl. Sci., 7(1), 7-17.
Tarekegn, W., & Seyoum, M. (2020). Effects of anthropogenic activities on macroinvertebrate assemblages in the littoral zone of Lake Hawassa , a tropical Rift Valley Lake in Ethiopia. Lakes Reserv.: Res. Manag.(April 2019), 1-11.
Tzortzis, M., Svoukis, E., & Tsertos, H. (2004). A comprehensive study of natural gamma radioactivity levels and associated dose rates from surface soils in Cyprus. Radiat.Prot.Dosim., 109(3), 217-224.
Ugbede, F., & Akpolile, A. (2019). Determination of Specific Activity of 238U, 232Th and 40K and Radiological Hazard. J. Appl. Sci. Environ. Manage., 23(4), 727-733.
Ugbede, F., & Benson, I. (2018). Assessment of outdoor radiation levels and radiological health hazards in Emene Industrial Layout of Enugu State, Nigeria. Int. J. Phys. Sci., 13(20), 265-272.
UNSCEAR. (1993). Sources and effects of ionizing radiation: UNSCEAR 1993 report to the General Assembly. New York, NY: United Nations.
UNSCEAR, .. (2008). Sources and Effects of Ionizing Radiation, Report to the General Assembly, with Scientific Annexes. New York: United Nations.
UNSCEAR. (2000). Sources and Effects of Ionizing Radiation:United Nations Scientific Committee on the Effects of Atomic Radiation UNSCEAR 2000 Report to the General Assembly, with Scientific. New York: UNSCEAR 2000 Report.