Prof. Harold Wilson Tumwitike Mapoma

Prof. Harold Wilson Tumwitike Mapoma

Co-author

Physics & Biochemical Sciences

28 publications

Besides teaching and consultancy, Prof. H.W.T. Mapoma has a great passion for research and skills gathering in Environmental Science and Sanitation. He has more than 10 years of teaching experience in environmental pollution and management, water resources management, hydrogeochemical studies, appli...

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Heavy metals in water, sediment, fish and associated risks from an endorheic lake located in Southern Africa

Journal Article
Published 2 years ago, 554 views
Author
L. L. J. Kamzati
Co-authors
Assoc. Prof. Chikumbutso Chiziwa Kaonga, Mr. Fabiano Thulu, S. M. Abdel-dayem, A. J. Anifowose, R. C. G. Chidya, U. Chitete-Mawenda, H. Sakugawa, Prof. Harold Wilson Tumwitike Mapoma
Abstract
The study assessed heavy metals (Cd, Cu, Fe, Mn, Pb and Zn) and physico-chemical parameters in water, sediments and fish from an endorheic lake (Lake Chilwa) in Malawi. It was observed that pH (max. 9.7), EC (max. 2936 μS/cm), TDS (max. 2119 mg/L), NO3− (max. 6.6 mg/L) and PO43− (max. 1.3 mg/L) were higher in the dry season than in the rainy season. Pb was not detected in all samples. However, the rest of heavy metals were detected with significant values of Mn and Cu in fish (Mn: 0.015–1.18 mg/kg dry weight, dw; Cu: 0.41–0.92 mg/kg dw) and sediment (Mn: 2.25–10.66 mg/kg dw; Cu: n.d–1.63 mg/kg dw). The concentrations of heavy metals in fish samples were below the maximum limits for edible fish recommended by Food and Agriculture Organization/World Health Organization: Cd (0.1 mg/kg), Cu (3 mg/kg), Fe (43 mg/kg), Pb (0.2 mg/kg), Mn (2–9 mg/kg) and Zn (60 mg/kg). The calculated target hazard quotients (ranged from 0.001 to 1.07) indicated no human risks from fish consumption. Furthermore, dry season values for Mn, Cu and Zn in sediments were significantly higher (p < 0.05) than those of the rainy season. Conversely, Fe in sediments was significantly higher (p < 0.05) in the rainy season than in the dry season. The use of fertilizer and indiscriminate disposal of metal products contributes to the observed levels. This calls for reinforcement of suitable agricultural and waste management practices in the study area.
Year of Publication
2020
Journal Name
International Journal of Environmental Science and Technology
Volume
17
Issue
1
Page Numbers
253 - 266
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