Assessment of trace and radioactive elements risk in the artisanal and small-scale gold mining sector

Abstract

Currently, the mining industry in Tanzania faces significant challenges including a significant policy research gap. In this work, different indices were applied to assess the health risk of people living and working in Rwamagasa artisanal and small-scale gold mines compared to existing Tanzanian and international standards. This dissertation has focused on quantifying and assessing the risk of selected trace and radioactive elements in a small-scale mining area. Furthermore, the present study analyzed and thus gives some recommendations on issues surrounding the Tanzanian mineral and mining policymaking process. Building on existing work on miner’s health risk, the present study asks: What are the levels of trace and radioactive elements in the studied mining areas compared to the recommended local and international limits? What is the health risk due to trace and radioactive elements exposure to mine workers and the surrounding communities? What are some of the deficiencies in the structure of the Tanzanian mineral and mining regulatory framework that are relevant to the environment and public health in artisanal and small-scale gold mines (ASGM)? The hyper pure germanium detector (HPGe) was used for radioactivity analysis. The soil trace elements were analyzed using the energy dispersive X-ray florescence (ED-XRF) technique. The radon gas levels were measured using the Alpha Guard radon monitor. Different literatures survey digest were used to assess the appropriate works on the regulatory and legal framework of the mining sector in Tanzania. The levels of trace elements, carcinogenic and noncarcinogenic health risks revealed that children were more at-risk compared to adults. The hazard index for all pathways was 1.77. This index suggested that the residents of the studied sites were at a high risk of non carcinogenic effects due to mining operations. The carcinogenic risk for adults and children was found to be 3.42×10-5 and 6.16×10-5 , respectively, which were higher than the tolerable limit (1×10-6 ). The results on radioactivity; mean effective dose; annual gonadal equivalent and absorbed dose; radium equivalent; internal and external hazard indices; alpha and gamma indices; and the radon gas revealed high values – approximately 60% higher than the levels that were found in the control area. The Tanzania mining policy-making process needs to have a circular model with the inclusion of scientific inputs as well as societal involvement at every stage of formulation. The present study recommends further studies especially those that use human samples and human subjects in attempting to discover more on the risk posed by mining operations on human health. Also, sustainable mining awareness to people of Rwamagasa is ii recommended. Furthermore, the present study suggests developing a document that govern the Tanzania artisanal and small-scale mining subsector.