College of Engineering and Technology

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Browsing College of Engineering and Technology by Subject "accrued plants"

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    Evaluation of heavy metals pollution in soil and plants accrued from gold mining actvities in geita, Tanzania
    (University of Dar es Salaam, 2008) Bitala, Manfred Felician
    Mining activities are known to pollute the environment in different ways. To understand the status of heavy metal pollution in areas surrounding the Geita Gold mines, in Tanzania, a study was undertaken at Nyakabale Village close to Geita Mining activities. The main objective was to quantify the level of heavy metals in both soil and plants and to identify social problems accrued from mining activities in the study area. The presence and quantity of seven heavy metals As, Cd, Cr, Pb, Hg, Cu and Zn were analyzed using Atomic Absorption Spectrometer (AAS) from soils, pasture species and three crop species. Plant pastures species of Sporobolus pyramidalis, Hyporrenia rufa and Cyperus and three cultivated crops; Zea mays (maize), Manihot esculenta (Cassava) and Oryza sativa (rice) were collected from the study area and analyzed. The cassava was analyzed for both leaves and roots/tubers. The results indicated that in soils the heavy metals concentration ranged between 12.5mgkgi'l to 19,790mgke while in plants the range was from hngke to 7,695mgkedry weight. On average heavy metals pollution in soils was between 36 to 6,000 times above the standards per metal, while in plants the heavy metals concentration was between 3 to 9,000 times higher per metal than the standards set by WHO and FAO. The results also indicated soil pH ranging from acidic (4.7) to slightly basic (7.60) implying soil acidification. All the respondents interviewed in Nyakabale Village associated the gold mining activities to the emergency of new human diseases and significant increase in the incidences of other common diseases such as malaria, non-bacterial diarrhoea, Pneumonia and Acute Respiratory Infections. From the results it can be concluded that Nyakabale Village and the immediate environment are severely polluted by heavy metals from gold mining activities of Geita Gold Mines and hence predisposing the areas to high risk of human health, livestock and other terrestrial and aquatic life and potentially to Lake Victoria Basin at large.