Assessment of the salt from Pemba for trace elements and toxic heavy metals by energy dispersive x-ray fluorescence spectrometry

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Date
2015
Journal Title
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Publisher
University of Dar es Salaam. Dar es Salaam
Abstract
Human exposure to salt arises mainly from the diet and occasionally from medical use. Human intake of heavy metals through the food chain has been widely reported through the worldwide. The present study aimed to assess the salt from Pemba for trace elements and toxic heavy metals using Energy Dispersive X-Ray Fluorescence (EDXRF) spectrometry. Forty three (43) salt samples were directly collected from small industries’ salt farm in Tanzania. The salt samples were collected from three main locations, twenty six (26) samples from North Pemba (NP salt), twelve (12) samples from South Pemba (SP salt) and five (5) samples from Kunduchi Dar-es-Salaam (KN salt). The mean concentrations of analyzed Na, Al, Cl, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, I, Pb, Th and U were determined. All the mean concentrations of the selected elements were found to be above MDL except the concentration of As which was found to be BDL 0.03 µg/g for all locations of salt sampling. The concentrations of Cu and Co were found to be BDL 1.39 µg/g and 3.36µg/g for only SP salt sampling location. Generally, the heavy metal concentrations in the present study were compared with the literature values and Maximum Tolerable limits (MTLs) of International organizations. The daily Intake Rate of essential elements Na, Cl, K, Ca, V, Cr, Mn, Fe, Cu, Zn and I, as well as %Contribution of Daily Intake Rate (DIR) on Upper intake Level (UL) were calculated . Contributions to the daily intake of most of the essential elements of salt are well below the Tolerable Upper Intake Levels for the respective elements. Thus, the percentage contributions to the daily intake of all essential elements (except Na, V and I) due to consumption of the salt from Pemba and that from Kunduchi do not exceed the ULs. The contributions to the daily intakes of Na, V, Pb, U and Cd for present study were higher compared to MTLs set by EFSA in relative to other literature.
Description
Available in print form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark (THS EAF QC462.T85A22)
Keywords
Trace elements, Chemical elements, X-ray spectroscopy
Citation
Abdulla, M.J (2015) Assessment of the salt from Pemba for trace elements and toxic heavy metals by energy dispersive x-ray fluorescence spectrometry, Master dissertation, University of Dar es Salaam, Dar es Salaam