Browsing by Author "Makundi, Ismael N."

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    ASSESSMENT OF RADIOACTIVITY LEVELS IN COAL AND COAL ASH IN KIWIRA COAL MINE USING GAMMA-RAY SPECTROMETRY
    (College of Natural and Applied Sciences, 2018) Makundi, Ismael N.; Nyaki, Mungubariki M; Mohammed, Najat K.
    This study aimed to assess the radioactivity levels and associated dose rates from the naturally occurring radionuclides 226Ra, 232Th and 40K in coal and coal ashes at Kiwira coal mine. The radioactivity of 40 representative coal, fly ash samples were measured using gamma spectroscopy of the Tanzania Atomic Energy Commission (TAEC) in Arusha, Tanzania. The activity concentrations of 226Ra, 232Th and 40K in coal and coal ashes from Kiwira were higher by several orders of magnitude than their worldwide average values. The calculated radium equivalent activity, the air absorbed dose rate, external hazard index and the average annual effective dose rate in fly ashes were 1335 ± 60 Bq kg-1, 610 ± 29 nGy h-1, 4 ± 0.4, 738 ± 52 μSv y-1 which were higher than the international recommended values of 370 Bq kg-1, 57 nGy h-1, and 70 μSv y-1 for fly-ashes respectively. The results provide information for the radiation protection when the coal and its by-products in the vicinity of Kiwira coal field is used. The data can be used by the authorities to design an appropriate method for handling wastes and implement intervention measures to protect the miners, the public as well as the environment.
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    Impact of North Mara gold mine on the element contents in fish from the river Mara, Tanzania
    (Springer, 2016) Mohammed, Najat K.; Ntarisa, A. V. R.; Makundi, Ismael N.; Kucˇera, J.
    The aim of the study was to determine element concentrations in lungfish and catfish from the river Mara with INAA and EDXF to assess the health impact of the North Mara gold mine (NMGM) in Tanzania. Twenty samples of each species were collected from two sites downstream and upstream along the river Mara in the vicinity of NMGM. The sampling sites were 70 km apart. Significantly higher concentrations (p B 0.05) of Cr, Ni, Cu, and Se in one of the species taken downstream than in those taken upstream might indicate contamination of the river Mara caused by the mining activities.