|Preliminary environmental assessment of metal contamination from miningand urban areas: A case study of the Ngwerere and Kafue Rivers, Zambia|
Muzungaire, L. (2013). Preliminary environmental assessment of metal contamination from miningand urban areas: A case study of the Ngwerere and Kafue Rivers, Zambia. MSc Thesis. Universiteit Antwerpen/VUB/Universiteit Gent: Antwerpen, Brussel, Gent. 17, 58 pp.
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Environmental pollution due to metal contaminants is of major concern globally. Most chemical discharge is waterborne and consequently, the highest impact of contamination is on the aquatic environment. Therefore, aquatic habitats are crucial in investigating levels of toxicity imposed and designing regulatory policies thereof. The general objective of this study was to address the potential risk from metal pollution sources in Zambia on the local environment and eventual risk to the local communities through direct intake of contaminated water and /or food items. This study was divided into two sub-studies namely; (I) impacts of mining activities along the Kafue River and (II) impacts of using municipal wastewater effluents in agriculture; along the Ngwerere River of Lusaka. Metal concentrations were analyzed in the non-living environment (sediments and water) and additionally, edible fish species (Brycinus imberi; Clarias ngamensis; Hepestus odoe; Marcusenius Macrolepidotus; Oreochromis andersonii, Oreochromis macrochir; Sargochromis codringtonii; Schilbe intermedius; Serranochromis angusticeps; Synodontis macrostoma and Tilapia rendalii) while sampled in Kafue River. Food plants; Brassica rapa; Phaseolus vulgaris; Cucurbita maxima; Brassica napus and Triticum aestivum were sampled in Ngwerere. Results showed a strong decreasing gradient in concentrations (both environment and fish) with increasing distance away from the mining region; leading to the evidence that mining is the primary source of metal pollution on the Kafue River. For Copperbelt sediments Cu and As surpassed USEPA limits while Zn was above FAO permissible limits in all fishes. Ngwerere water was unsafe for irrigation use in the case of Mn, Fe, and Cu according to EC guidelines and P. vulgaris posed a human health risk as concentrations were much higher than certified safe limits of CODEX and EC. Indeed, the impact of metal pollution cannot be overemphasized and intervention strategies are needed.