ARSENIC IN THE GOLD MINING AREAS OF NORTHERN TANZANIA AND POTENTIAL HEALTH IMPACTS (Invited Presentation)

Groundwater pollution is becoming a serious problem to human health worldwide. The occurrence of such pollutants can either be geogenic or anthropogenic. Elevated concentrations of arsenic (>10 µg/L) is reported in the northern part of Tanzania and are associated with gold mining activities within Lake Victoria Basin (LVB). The geology of LVB is dominated by greenstone belts in the North-Western region up to Mpanda and Lupa Mineral fields in the Ubendian system of the western parts of Tanzania. These regions are characterized by small, medium and large scale mining, using various technologies. A number of adverse human health effects are noticed among the communities living around the mining areas. Based on developed geostatistical model using past study results on total arsenic in 9 districts, a spatial trend (R² =0.19) in the east-west transect was noticed. In addition, a spatial trend (R² =0.009) was observed along the north-south transect. This study aims at improving knowledge on the spatial distribution of arsenic by increasing number of samples well distributed within the study regions where mining activities are taking place. Furthermore, we are using geochemical models to characterize total As and its species at various pH conditions. We are also using geostatistical models to characterize spatial trends of As and its species throughout the basin. The results of this study are very potential to improve drinking water suppliers in targeting safer groundwater sources.