Effects of Seasonal Change on the Levels of Geogenic Radionuclides in Sand and Rocks from Tyaa River deposit in Kitui County


  • Stanley Muthama Matsisti Department of Physical Sciences, South Eastern Kenya University, P.O BOX 170-90200 Kitui, Kenya
  • J. M. Linturi Department of Physical Sciences, South Eastern Kenya University, P.O BOX 170-90200 Kitui, Kenya
  • J.M. Kebwaro School of Pure and Applied sciences, Karatina University, P.O BOX 1957-10101 Karatina, Kenya
  • O. M. Maweu Department of Physical Sciences, South Eastern Kenya University, P.O BOX 170-90200 Kitui, Kenya
Keywords: Construction sand, Natural radioactivity, gamma spectrometer, Dry season, Tyaa River


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A total of 56 samples of raw building materials (26 rocks and 30 sand samples) each weighing 500g were randomly sampled along the riverine for the alternate rainy and dry seasons. Gamma-ray spectrometric analysis of rocks sampled during the rainy season reports an average activity concentration of 226Ra, 232Th and 40K of 22±1.1 BqKg-1, 46±2.3 BqKg-1, and 659±33 BqKg-1 respectively, while the sand collected during the same season revealed a mean activity of 27±1.4 BqKg-1, 49±2.5 BqKg-1and 824±41 BqKg-1 for 226Ra, 232Th and 40K respectively. A repeat study during dry season reported higher activities for 226Ra, 232Th, and 40K for most samples. The corresponding dose rates and radiological indices estimated from specific activities of 226Ra, 232Th and 40K showed an upward trend as seasons changed from rainy to dry. However, both seasons reported radiation doses below the permissible limits.


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Ahmed, M., Das, S., Haydar, M., Bhuiyan, M., Ali, M., Paul, D. J. J. o. N., & Physics, P. (2014). Study of Natural Radioactivity and Radiological Hazard of Sand, Sediment, and Soil Samples from Inani Beach, Cox’s Bazar, Bangladesh. 4(2), 69-78.

Baeza, A., Del Rio, M., Jimenez, A., Miro, C., Paniagua, J. J. J. o. r., & chemistry, n. (1995). Influence of geology and soil particle size on the surface-area/volume activity ratio for natural radionuclides. 189(2), 289-299.

Beretka, J., & Matthew, P. J. H. p. (1985). Natural radioactivity of Australian building materials, industrial wastes and by-products. 48(1), 87-95.

Cowart, J., & Burnett, W. J. J. o. E. Q. (1994). The distribution of uranium and thorium decay-series radionuclides in the environment—a review. 23(4), 651-662.

Ebaid, Y. J. R. J. P. (2010). Use of gamma-ray spectrometry for uranium isotopic analysis in environmental samples. 55(1-2), 69-74.

El-Taher, A., & Al-Zahrani, J. (2014). Radioactivity measurements and radiation dose assessments in soil of Al-Qassim region, Saudi Arabia.

El Mamoney, M., & Khater, A. E. J. J. o. E. R. (2004). Environmental characterization and radio-ecological impacts of non-nuclear industries on the Red Sea coast. 73(2), 151-168.

Fujiyoshi, R., & Sawamura, S. J. S. o. t. T. E. (2004). Mesoscale variability of vertical profiles of environmental radionuclides (40K, 226Ra, 210Pb and 137Cs) in temperate forest soils in Germany. 320(2-3), 177-188.

Higgy, R., El-Tahawy, M., Abdel-Fattah, A., & Al-Akabawy, U. J. J. o. E. R. (2000). Radionuclide content of building materials and associated gamma dose rates in Egyptian dwellings. 50(3), 253-261.

IAEA. (1996). International basic safety standards for protection against ionizing radiation and for the safety of radiation sources, safety series no. 115. IAEA, Vienna.

IAEA., & IAEA. (2010). Handbook of parameter values for the prediction of radionuclide transfer in terrestrial and freshwater environments: International Atomic Energy Agency.

ICRP. (2005). Low-dose Extrapolation of Radiation-related cancer risks. . International Commission on Radiological Protection. Oxford: Pentagon press.

Karakelle, B., Öztürk, N., Köse, A., Varinlioğbrevelu, A., Erkol, A., Yilmaz, F. J. J. o. R., & Chemistry, N. (2002). Natural radioactivity in soil samples of Kocaeli basin, Turkey. 254(3), 649-651.

Malanca, A., Gaidolfi, L., Pessina, V., & Dallara, G. J. J. o. e. r. (1996). Distribution of 226Ra, 232Th, and 40K in soils of Rio Grande do Norte (Brazil). 30(1), 55-67.

Mustapha, A. O., Patel, J., & Rathore, I. J. R. p. d. (1999). Assessment of human exposures to natural sources of radiation in Kenya. 82(4), 285-292.

Nyamai, C. M., Mathu, E. M., Opiyo-Akech. N., & Wallbrecher. E. (2003). A Re-appraisal of the Geology, Geochemistry, Structures, and Tectonics of the Mozambique belt in Kenya, East of the Rift System. African Journal of Science and Technology (AJST), 4, 51-71.

Tzortzis, M., Svoukis, E., & Tsertos, H. J. R. p. d. (2004). A comprehensive study of natural gamma radioactivity levels and associated dose rates from surface soils in Cyprus. 109(3), 217-224.

UNSCEAR. (1988). Sources of ionizing radiation. United Nations Scientific Committee on Effects of Atomic Radiation 2000 report, United Nations, New York. 565-571.

UNSCEAR. (2000). United Nations Scientific Committee on the Effects of Atomic Radiation. Sources, effects, and risks of ionization radiation Report to The General Assembly, with Scientific Annexes B: Exposures from Natural Radiation Sources. 453-487.

UNSCEAR. (2008). United Nations Scientific Committee on the effect of Atomic Radiation report to the general assembly. Annex B: exposures of the public and workers from various sources of radiation.

Valkovic, V. (2000). Radioactivity in the environment: physicochemical aspects and applications: Elsevier.

Varley, N., & Flowers, A. J. H. p. (1998). Indoor radon prediction from soil gas measurements. 74(6), 714-718.

Xinwei, L., Lingqing, W., Xiaodan, J., Leipeng, Y., & Gelian, D. J. R. p. d. (2005). Specific activity and hazards of Archeozoic-Cambrian rock samples collected from the Weibei area of Shaanxi, China. 118(3), 352-359.

How to Cite
Matsisti, S., Linturi, J. M., Kebwaro, J., & Maweu, O. M. (2019). Effects of Seasonal Change on the Levels of Geogenic Radionuclides in Sand and Rocks from Tyaa River deposit in Kitui County. International Journal of Fundamental Physical Sciences (IJFPS), 9(1), 14-19. https://doi.org/10.14331/ijfps.2019.330124