Exploring the fate of mercury in artisanal gold mining of the Lake Victoria Gold Field

This study will investigate quantitative and qualitative mercury availability in the environment surrounding artisanal and small-scale gold mining (ASGM) locations in Tanzania, where mercury contamination is of concern with regard to the health of community members and others who consume food products originating from the area. Although mercury contamination can be lessened by appropriate controls and proper handling methods, such measures are not routinely applied in Tanzania, where mercury has been documented in different environments and studies. Mercury can be transported away from emission sources by riverine systems to large water bodies like Lake Victoria. The resulting fish contamination can be significant, which is a particularly serious issue as fish are the major protein source in the region and the whole country. In Tanzania, very little data is available on levels of methylmercury in biota and sediments and on the contribution that ASGM activities make to these levels. Further, there is little information on the relative importance of riverine and atmospheric processes in transporting mercury from sources to ecosystems. All these aspects must be taken into accoutn in order to understand the magnitude of mercury impacts on the environment and on human beings. This project will develop data on levels of mercury downwind and downstream from ASGM activities in water, suspended particulate matter, sediments, and fish and improve understanding of spatiotemporal variations of mercury levels. Inclusion of methylmercury in the analysis represents a significant extension of the PI’s earlier work.