Evaluation of Mercury content in selected food crops grown at Msugu mining area, Geita in Mwanza, Tanzania

Mercury (Hg) emissions from informal gold mining operations present a serious environmental problem in developing countries. A survey of various uses of mercury in Tanzania has been conducted in order to identify potential sources of mercury contamination and human exposure to mercury poisoning. Gold Mercury using mercury in small-scale mining accounts for the large part of mercury contamination. The aim of the study was to investigate heavy metal i.e mercury concentration in selected crops, grown at Mgusu village. These food crops were beans (Phoseolus fulgaris ), ground nuts (Arachis hypogaea0, sweet potatoes (Iponea batata) and yams (Calocasia esculcuta ). Sample were analyzed for mercury content. The highest concentration was 462ppb(dw), which found in sweet potatoes. The lowest value found mostly have revealed that mining activities performed with these small-scale miners a Mgusu mining contribute more mercury pollution in the environment. The analysed bean, sweet potato samples grown nearly to the active and abandoned washing ponds showed that mercury metal was present in significant concentrations. Thus mercury was deposited into those areas and proved hat mercury pollution is mainly due to poor handling of mercury during washing, amalgamation and gold melting in open air. Therefore, the impact of the gold mining to the environment is very evident at Mgusu Village. More efficient are extraction techniques, safe amalgamation methods, use of retort equipment, mine bac-filling practices, protection of water supplies and receiving river 9Mgusu River) are more advised to the studied rea. Education, also is identified in this work as an important measures to help address the serious mercury emissions from gold-mining operations.