Indoor radon concentration levels and annual effective doses for residence of houses near uranium deposit in Bahi district, Dodoma, Tanzania

The objective of this study was to determine the levels of indoor radon concentration in houses in Bahi District situated in the neighbourhood of uranium deposit. The study aimed also to assess the annual effective dose due to indoor radon exposure to individuals residing in the houses as a step to control the radon exposure in Tanzania. Two villages were involved in this study; Bahi Makulu, which is within the proximity of Uranium deposit and Bahi Sokoni, which is about 7 km from the deposit. The Indoor radon concentration levels were detected using Alpha Guard radon monitor and the obtained mean concentration levels are presented and compared with the mean concentrations levels published in literature. The results revealed that 78% of the houses involved in this study have concentration levels of indoor radon above the reference level of 100 Bq/m3 set by WHO 2009. The levels are higher in traditional houses which are mostly built with poor ventilation than the modern houses with good ventilation. Out of the two villages involved in this study, Bahi Makulu which is closer to the uranium deposit has significantly higher (p<0.01) concentrations of indoor radon than Bahi Sokoni. The calculated annual effective doses for the population in both villages are higher than the dose reference level of 1 mSv/y. Key words: Indoor Radon, Bahi District, Uranium deposit, Annual effective dos

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

A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy in Environmental Sciences and Engineering of the Nelson Mandela African Institution of Science and TechnologyCurrently, 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

Health Risk Assessment of Trace Elements in Soil for People Living and Working in a Mining Area

This research article published by Hindawi, 2021The present study used soils collected from a small-scale gold mine area to determine the health risks due to trace elements to the at-risk population in the study area. The work involved 74 soil samples from four sampling categories: 29 samples were from the mining pits (MD), 18 samples from the first washing area (WA), 17 samples from the second washing area (WB), and 10 samples from the control area (C). All samples were analyzed for Cr, Cu, As, Pb, Cd, Co, Ni, Zn, and Hg using the Energy Dispersive X-Ray Florescence (ED-XRF) method. Trace element levels were found to vary across the four sampling categories. The concentrations of trace elements recorded from different sampling categories varied in an increasing order of MD > WA > WB > C. Mercury was detected in the highest levels (max. 3.72 ± 0.15) at WB while it was not detected in the samples from C. Samples from MD indicated that Cu (max. 737.66 ± 1.3 mg/kg) was found in the highest levels whereas Hg (mean = 0.007 mg/kg) was the lowest. At WA, Cu (max. = 178.97 ± 2.46 mg/kg) registered the highest average concentration while Hg (mean = 0.05 mg/kg) had the lowest concentration. For WB, Cu (max. = 230.66 ± 3.99 mg/kg) was found in the highest concentration. The hazard index value for all exposure routes was found to be 1.77, making noncarcinogenic effects significant to the adult population. For children, the hazard index value was 9.11, showing a severe noncarcinogenic effect on children living in the study area. For the noncancer effects through the inhalation pathway, the risk posed by Ni, Cu, Zn, and Pb was negligible for both adults and children, while Co posed the highest noncancer risk for children. Cobalt also indicated the highest noncancer risk for children through the dermal pathway, while As indicated the highest noncancer risk to children through ingestion. For the cancer risk, the adults were more at risk compared to children, except for As and Co through the dermal pathway posing the highest threat. Trace element concentrations, hazard quotient, and hazard index values indicated that the area was polluted and that noncarcinogenic and carcinogenic effects on residents and miners were significant. Therefore, there is a need to put in place mining regulations aimed at protecting the at-risk human population in the study area

The influence of gold mining on radioactivity of mining sites soil in Tanzania

The activity of 226Ra, 232Th and 40K in soil samples were measured by gamma spectrometry using high-purity germanium detector. The study involved 40 samples from four divisions: 10 samples each were drawn from the control area (CTR), washing area 1 (W1), washing area 2 (W2) and the mining pits (MP). Radium and Thorium were measured in highest value (80.44 and 94.62) Bq/kg, respectively at MP-9 while the lowest levels (1.56 and 0.96) Bq/kg, respectively were detected at MP-2. At W1, 40K (max. 887.5 Bq/kg) recorded the highest mean level while 232Th (mean=16.7 Bq/kg) had the lowest level. For W2, 40K (max. 1535.7 Bq/kg) recorded highest level and 232Th (mean = 8.1 Bq/kg) recorded the lowest (10.7 Bq/kg). Results further show that mean activity levels of 226Ra, 232Th and 40K fromining area 42.5, 35.5 and 652.4Bq/kg, respectively. In comparison, the respective average activity for 40K, 226Ra, and 232Th recoded 118.4, 14.5 and 9.7 Bq/kg, respectively in control area. For the sake of assessing the suitability of building materials, hazard indices were calculated and their results were less than unity indicating that, building materials are safe. The annual gonadal equivalent dose, representative gamma index, alpha index revealed values of 484.8 µSv/y, 1.1 and 0.2, respectively. The average annual effective dose was 85.5 mSv which is about 8% greater than the world average. Results show that mining activities in Rwamagasa might be posing radiological hazard to people. Therefore, measures on radioactive materials to the miners and the surrounding community are recommended

Artisanal and small-scale mining in Tanzania and health implications: A policy perspective

The mineral sector, especially its small-scale subsector, has become significant in the emerging economies of the Global South. Tanzania is the focus of this policy exposition paper because, aside from Ghana and South Africa, Tanzania is ranked 4th in Africa in terms of its mineral deposits and small-scale mining activities. The focus is also on artisanal and small-scale mining (ASM) because ASM operations have significantly increased in recent times across this mineral-rich country of East Africa. This is done against a negative backdrop-labelling of ASM as unsustainable, environmentally unfriendly, inefficient, and illegal. Tanzania has made some progress to respond to some of the challenges in the mining sector to improve the micro and macroeconomics of the country. Some areas remain challenging including the lack of proper environmental health education for the ASM miners; the lack of clear national-level policies to guide health-related matters in the ASM subsector, and the small capital investment of the ASM subsector to support healthy mining practices. The details related to the persistence of these challenges are not well known, particularly those that pertain to policymaking. This article attempts to evaluate the policy environment of the ASM subsector in Tanzania and propose appropriate actions for the future of mineral resource policymaking in Tanzania