Research Repository :: Browsing by Author "Banzi, Firmi B."

Browsing by Author "Banzi, Firmi B."

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ASSESSMENT OF HEAVY METAL CONCENTRATION IN WATER AROUND THE PROPOSED MKUJU RIVER URANIUM PROJECT IN
(College of Natural and Applied Sciences, 2015) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
Effective verification for compliance with water quality standards in uranium mining in Tanzania requires data sensitive to monitor heavy metal concentration in water around the Mkuju River Uranium Project before mining commences. The area susceptible for pollution by the project was estimated using AERMOD dispersion model and found to cover about 1300 km2. Thirty one surface and groundwater samples were collected and analysed for heavy metals and physicochemical properties using ICP-MS and standards techniques, respectively. The physicochemical properties for water samples analysed ranges from 5.7 to 7.8 for pH, 2.8 to 80.2 mg/L for TDS and 15 to 534.5 mS/cm for EC. These values show that the water in the vicinity of the Mkuju River Uranium Project is normal. The ranges of concentration of heavy metals (μgL-1) determined in water ranges were: Al(2 to 9049), Cr(0.2 to 19.96), Mn (0.1 to 1452),Fe(2 to 53890),Co(0.02 to 27.63), Ni(0.2 to 9.7), Cu(2 to 17), Zn(2 to 62.94), As(0.4 to 19.17), Cd(0.02 to 0.14), Pb (0.02 to 78.68), Th (0.002 to 1.73),U(0.002 to 29.76). These values are below the tolerance levels of concentrations set by different International organisations. Therefore heavy metal toxicity in the study area is marginal. The parameters that could serve as baseline data because of their enhanced sensitivity to pollution were (i) concentration of chromium, cobalt, nickel, copper, zinc, arsenic, cadmium and lead in water (ii) pH, TDS and EC for water, (iii) TDS ratio for surface to ground water values and (iv) correlation coefficients between the heavy metals. However, since TDS values are season dependent, this indicator can serve as baseline data when measured during the dry season as was the case in the study.
Assessment of Heavy Metal Concentration in Water around the Proposed Mkuju River Uranium Project in Tanzania
(2015) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
Effective verification for compliance with water quality standards in uranium mining in Tanzania requires data sensitive to monitor heavy metal concentration in water around the Mkuju River Uranium Project before mining commences. The area susceptible for pollution by the project was estimated using AERMOD dispersion model and found to cover about 1300 km2 . Thirty one surface and groundwater samples were collected and analysed for heavy metals and physicochemical properties using ICP-MS and standards techniques, respectively. The physicochemical properties for water samples analysed ranges from 5.7 to 7.8 for pH, 2.8 to 80.2 mg/L for TDS and 15 to 534.5 mS/cm for EC. These values show that the water in the vicinity of the Mkuju River Uranium Project is normal. The ranges of concentration of heavy metals (µgL-1 ) determined in water ranges were: Al(2 to 9049), Cr(0.2 to 19.96), Mn (0.1 to 1452),Fe(2 to 53890),Co(0.02 to 27.63), Ni(0.2 to 9.7), Cu(2 to 17), Zn(2 to 62.94), As(0.4 to 19.17), Cd(0.02 to 0.14), Pb (0.02 to 78.68), Th (0.002 to 1.73),U(0.002 to 29.76). These values are below the tolerance levels of concentrations set by different International organisations. Therefore heavy metal toxicity in the study area is marginal. The parameters that could serve as baseline data because of their enhanced sensitivity to pollution were (i) concentration of chromium, cobalt, nickel, copper, zinc, arsenic, cadmium and lead in water (ii) pH, TDS and EC for water, (iii) TDS ratio for surface to ground water values and (iv) correlation coefficients between the heavy metals. However, since TDS values are season dependent, this indicator can serve as baseline data when measured during the dry season as was the case in the study.
Assessment of Natural Radioactivity in Soil and its Contribution to Population Exposure in the Vicinity of Mkuju River Uranium Project in Tanzania
(Science Technol, 2016) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
The level of 226Ra, 232Th and 40K was established in soil collected in an area about 1,300 km2 in the vicinity of Mkuju uranium project in Tanzania and selected points in the concession using HPGe spectrometer and associated exposure risks to population were estimated. The radioactivity concentration in the vicinity range (Bqkg-1) for 226Ra (24.94 to 53.50), 232Th (20.86 to 47.14), and 40K (344.50 to 697.54). Whereas, radioactivity in the concession range for 226Ra (2430.00 to 4200.00), 232Th (130.00 to 220.00), and 40K (1293.30 to 1466.10). On average the radioactivity in the concession were about 89, 5 and 3 times high than those in the vicinity. Based on the measurements, the hazards attributable to use of soil from the vicinity for different purposes is marginal. However, the hazards indices indicate that soils from the concession have relatively a significantly risk by range of factors about 27 to 29 and 40 to 42 times high than in the vicinity for the external and internal hazards, respectively. Also the radium equivalent radioactivity, dose rate and effective dose tend to be significantly high in the concession than in the vicinity by range of factors from 27 to 29, 23 to 25 and 23 to 25, respectively. These findings reveals that soils in the vicinity of the project could pose less radiological risk to human health when compared to soil in the concession.
ASSESSMENT OF RADIOACTIVITY OF 226Ra, 232Th AND 40K IN SOIL AND PLANTS FOR ESTIMATION OF TRANSFER FACTORS AND EFFECTIVE DOSE AROUND MKUJU RIVER PROJECT, TANZANIA
(2017) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
Purpose. To establish pre-mining indicators to assess radiological impact as a result of release of radionuclides to environment during uranium mining at Mkuju River Project radioactivity of 226Ra, 232Th and 40K in soil, plants, fruits and cereals. Methods. The High Purity Germanium detector was used to determine the radioactivity and the data were subsequently used to establish soil to plant transfer factors and annual effective dose. Findings. The results revealed a strong positive correlation (r) of 0.947 and 0.950 for 226Ra and 232Th, respectively, between values determined in soils and plants. Implicit in these finding is that the distribution of radionuclides in soils is directly proportional to the corresponding radionuclides in plants. Originality. The roots of wild grass had the highest specific radioactivity (Bqkg-1) for 226Ra (2.15 ± 0.02), 232Th (1.43 ± 0.02) and 40K (198.16 ± 1.72) and the roots of cabbage had the highest values for 226Ra (1.38 ± 0.04), 232Th (1.34 ± 0.03) and 40K (146.12 ± 1.02) among the food crops, an indication of a higher ability to uptake radionuclides from soil. Similarly, since the TFs were found higher in wild grass for 226Ra (0.0533 ± 0.04), 232Th (0.0374 ± 0.002) and 40K (0.5297 ± 0.05) and cabbage for 226Ra (0.0362 ± 0.03), 232Th (0.0360 ± 0.001) and 40K (0.4173 ± 0.05). Practical implications. It is an evident that these plants can serve as good bio indicators to assess release of radionuclides from inside the mining site to the public domain. Moreover, the annual effective dose (mSvy-1) for 40K (0.23 ± 0.02), 226Ra (0.046±0.004) and 232Th (0.073 ± 0.006) in edible crops when consumed in the vicinity of the MRP before the mining operations were, as expected, insignificant.
Association of Iron Sulphides with Gold in Lake Victoria Gold field in Tanzania: A preliminary study
(2000) Banzi, Firmi B.
There is a resumed gold rush in Tanzania following liberalization of the private sector in 1993. Therefore, the need for finding mineral association with gold for quick location of gold rich areas is particularly high. Although such signatures already exist in some regions, their theoretical basis is still ill defined. The aim of this work is to resolve this problem by collecting and analyzing several rock samples obtained from different area around Lake Victoria gold field. The Energy Dispersive X-Ray Fluorescence technique was used to identify and quantify mineral elements and X-ray Diffraction was employed to identify phases of minerals. The preliminary results from XRF indicated that only five out of the expected gold associated mineral elements are found in Lake Victoria gold field: Fe (1- 24%), Co (4-67ppm), Cu (1-49 ppm), Pb (3-76 ppm) and As (15-88 ppm). Of particular interest is Pb element, which was found in all samples containing gold but gold was not found in all samples containing lead. The results from XRD showed that gold in Lake Victoria occurs in close association with chalcopyrite, pyrite and pyrrhotite. Work is in progress to identify mineral elements and phases, which can be used for quick location of gold rich area in the Lake Victoria gold field.
Challenging Issues in Regulating Uranium Mining in Tanzania
(Springer International Publishing, 2014-09) Banzi, Firmi B.; Msaki, Peter; Mohammed, Najat K.
Experiences have shown that unregulated uranium mining practices have led to significant radiological risk to workers, public and the environment. Tanzania is about to start uranium mining in different parts of the country. Although the legislation and regulations to control doses to workers, public and the environment are in place, there are challenges to adequately address best practice requirements during and after the mining operations. This paper provides an overview of the challenges in addressing the regulatory compliance
Distribution of Heavy Metals in Soils in the Vicinity of the Proposed Mkuju Uranium Mine in Tanzania
(Canadian Center of Science and Education, 2015) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
Tanzania is at advance stages in the preparation to start uranium mining at Mkuju River Deposit. In order to implement best practice in environmental management in uranium mining as required by national and international regulations and standards, a set of site specific baseline data have to be established prior the mining operation. In order to establish heavy metal baseline data for this purpose, a total of 84 soil samples were collected from clustered area of about 1,300 km2 at two depths: 0-15 cm and 15-30 cm. Analysis of the data using EDXRF showed a total metal concentration ranges of 3570-19400 for Al, 15200-58600 Fe, 400-1400 Mn, 15.2-54.9 Cr, 13.5-51.0 Zn, 2.2-45.3 Pb, 2.1-37.3 Cd, 0.2-23.0 Hg, 1.8-25.1Cu, 2.1-22.7 Ni and 0.8-9.1 mgkg-1for Co. Since the spatial distributions of heavy metals in the vicinity of the planned uranium mine are comparable to established global concentration ranges in soils, it is an indication that the distribution is natural. By virtue of their strong association with uranium and immobility in soil, spatial distributions of lead and copper concentrations would be more sensitive indicators for monitoring uranium related soil contaminants when the uranium mine become operational.
Distribution of Heavy Metals in Soils in the Vicinity of the Proposed Mkuju Uranium Mine in Tanzania
(Canadian Center of Science and Education, 2015) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
Tanzania is at advance stages in the preparation to start uranium mining at Mkuju River Deposit. In order to implement best practice in environmental management in uranium mining as required by national and international regulations and standards, a set of site specific baseline data have to be established prior the mining operation. In order to establish heavy metal baseline data for this purpose, a total of 84 soil samples were collected from clustered area of about 1,300 km2 at two depths: 0-15 cm and 15-30 cm. Analysis of the data using EDXRF showed a total metal concentration ranges of 3570-19400 for Al, 15200-58600 Fe, 400-1400 Mn, 15.2-54.9 Cr, 13.5-51.0 Zn, 2.2-45.3 Pb, 2.1-37.3 Cd, 0.2-23.0 Hg, 1.8-25.1Cu, 2.1-22.7 Ni and 0.8-9.1 mgkg-1for Co. Since the spatial distributions of heavy metals in the vicinity of the planned uranium mine are comparable to established global concentration ranges in soils, it is an indication that the distribution is natural. By virtue of their strong association with uranium and immobility in soil, spatial distributions of lead and copper concentrations would be more sensitive indicators for monitoring uranium related soil contaminants when the uranium mine become operational.
Effects of Impurities on the Structural and Magnetic Properties of Natural Iron Sulphides from the Lake Victoria Gold Field
(2001) Banzi, Firmi B.
In this thesis three techniques, namely, X-ray Fluorescence, X-ray diffraction and Moessbauer spectroscopy were used to study the effects of impurities on the structural and magnetic properties of natural iron sulphides from the lake Victoria gold field. Pyrite and pyrrhotite being the main component of the iron sulphide in this area were investigated.
Natural Radioactivity and Radiation Exposure at the Minjingu Phosphate Mine in Tanzania
(2000) Banzi, Firmi B.; Kifanga, Leonard D.; Bundala, Felician M.
In this paper the results of studies on activity and ambient radiation background around the Minjingu phosphate mine in Tanzania are presented. The outdoor dose rate in air and the activity levels of samples from and outside the mine were determined by thermoluminiscent dosimeters and a gamma spectrometer system with a Hyper Pure germanium detector system respectively. The determination of activity was made for the 226Ra, 228Ra, 228Th and 40K radionuclides. High concentrations of radium-226 were observed in phosphate rock (5760+/-107 Bq kg(-1)), waste rock (4250+/-98 Bq kg(-1)), wild leaf vegetation (650+/-11 Bq kg(-1)), edible leaf vegetation (393+/-9 Bq kg(-1)), surface water (4.7+/-0.4 mBq l(-1)) and chicken feed (4+/-0.1 Bq kg(-1)) relative to selected control sites. These findings suggest a radiation health risk particularly when the samples are ingested, because the internal exposure may give rise to an effective dose exceeding 20 mSv which is the annual limit of intake of natural radionuclides recommended by the ICRP. On the other hand, the radiation dose from ambient air over five years at the phosphate mine ranges from 1375 to 1475 nGy h(-1) with an average of 1415 nGy h(-1). The average is about 28 times that of the global average background radiation from terrestrial sources, and about 12 times the allowed average dose limit for public exposure over five consecutive years. Future investigations on the occupancy factor, external dose rate and radon and radon progeny exposure in drinking water, buildings and activity content in the locally grown foodstuffs are proposed, for the realistic quantification of the overall exposure of workers and public at Minjingu, and remedial measures for future radiation safety.
Natural Radioactivity in Water and Its Potential Human Health Risk in the Vicinity of Mkuju River Uranium Projectin Tanzania
(SciencePG, 2016) Banzi, Firmi B.; Msaki, Peter K.; Mohammed, Najat K.
Consistent with best practices in uranium mining, the collection and use of site characterisation data are indispensable to ensure compliance with regulations. To comply with this requirement, two samples from each of the 47 locations were collected in an area of about 1300 km2 in the vicinity and concession area of the Mkuju River Project. The samples were analysed for radioactivity using alpha spectrometry. The activity concentrations were used to estimate health risks attributable to the consumption of drinking water containing radionuclides. The range of activity concentrations (mBqL-1) were much higher in groundwater collected from the concession area for 238U (79.89 to 87.06), 234U (79.44 to 88.38), 226Ra (41.61 to 59.07), 232Th (5.32 to 9.41), and 228Ra (3.98 to 8.59) than in groundwater for 238U (20.61 to 47.21), 234U (21.70 to 49.10), 226Ra (16.80 to 43.45), 232Th (0.12 to 2.80), and 228Ra (0.10 to 2.43), and surface water for 238U (17.33 to 27.24), 234U (21.06 to 34.43), 226Ra (15.00 to 25.61), 232Th (0.16 to 2.10), and 228Ra (0.12 to 1.99) collected in the vicinity of the project. The calculated annual effective doses and carcinogenic risks resulting from the activity concentrations in drinking water were relatively marginal, since the activity concentrations were lower than the WHO permissible limits for drinking water. These findings suggest that the water resources at MRP are safe. Thus, since this study was conducted before mining activities, these data can be used as a baseline for monitoring potential future water pollution around the Mkuju River Project.
An Overview of the Global Threat Reduction Initiative's Physical Protection Work in Tanzania
(2010) Banzi, Firmi B.; Itamura, Michael T.; Robinson, Phillip W.; Strosinski, Micheal V.
The U.S. Department of Energy's (DOE) National Nuclear Security Administration (NNSA) established the Global Threat Reduction Initiative's (GTRI) mission to reduce and protect nuclear and radiological materials located at civilian sites worldwide. Internationally, over 80 countries are cooperating with GTRI to enhance security of facilities with these materials. In 2004, a GTRI delegation began working with the Tanzania Atomic Energy Commission, (TAEC). The team conducted site assessments for the physical protection of radiological materials in Tanzania. Today, GTRI and the Government of Tanzania continue cooperative efforts to enhance physical security at several radiological sites, including a central sealed-source storage facility, and sites in the cities of Arusha, Dar Es Salaam, and Tanga. This paper describes the scope of physical protection work, lessons learned, and plans for future cooperation between the GTRI program and the TAEC. Additionally the paper will review the cooperative efforts between TAEC and the International Atomic Energy Agency (IAEA) with regards to a remote monitoring system at a storage facility and to the repackaging of radioactive sources.
Radioactivity in Products Derived from Gypsum in Tanzania
(Nuclear Technology Publishing, 2000) Msaki, P.; Banzi, Firmi B.
Scientific investigations have long concluded that prolonged exposure to low dose radiation can induce deleterious effects in humans. The aim of this paper is to investigate the radioactivity of gypsum and gypsum derived products as part of a bigger project aimed at establishing radiation levels in materials or/and products suspected to have natural radioactivity radiation risk in Tanzania. In response to the concern expressed by the users of chalk sticks in some schools in Arusha municipality, it was found necessary to establish levels of radioactivity in this product and associated radiation risk. Natural radioactivity content was determined in chalk dust, natural gypsum and normal background soil using a hyper pure germanium spectrometer (HPGe). The soil measurements were used as control. Results have shown that the concentration of 226Ra and 228Ra nuclides found in chalk dust were 24.25 Bq.kg21 and 22.86 Bq.kg21 , respectively. These levels were lower or comparable to the corresponding 34.2 Bq.kg21 and 21.5 Bq.kg21 , respectively, found in soil. However, the radioactivity levels found in the chalk dust were five times higher than that found in the gypsum 5 Bq.kg21 for 226Ra and 4 Bq.kg21 for 228Ra. These values compare well with the value recorded for natural gypsum in Denmark of 7 Bq.kg21 for 226Ra and 4 Bq.kg21 for 228Ra by UNSCEAR. The calculated external (0.21) and internal (0.31) hazard indices due to radioactivity in chalk dust were respectively, lower than (0.26 and 0.35) hazard indices calculated for normal background soil. In both cases, the hazard indices were lower than the acceptable limits (<1) recommended for building materials. This study has shown that natural gypsum and gypsum derived products have traces of radioactivity. However, the associated levels are not detrimental to health.
A survey of background radiation dose rates and radioactivity in Tanzania
(2002-02) Banzi, Firmi B.; Msaki, P.; Makundi, Ismael
Potential terrestrial sources of naturally occurring elevated radiation levels have been identified in Tanzania. Thus, efforts are currently being undertaken to create a natural radiation database, in the form of a radiation level map of natural radioactivity, to be used to assess the associated radiation risk to public and workers. Background radiation dose rate was determined with thermoluminescent dosimeters for 7 y (1993-1999) in five stations. The average background radiation dose rates for these stations were as follows: Tropical Pesticides Research Institute (TPRI) (102 +/- 7 nGy h(-1)), Same (98 +/- 2 nGy h(-1)), Namanga (98 +/- 5 nGy h(-1)), University of Dar Es Salaam (99 +/- 2 nGy h(-1)), and Kilimanjaro Christian Medical Center (121 +/- 3 nGy h(-1)). These stations were found convenient from an economic point of view since the project has no funds to cover wider and/or more remote areas in Tanzania. For the sake of comparison, similar measurements were made for the same period at Minjingu phosphate mine. The mine was one of the suspected areas with elevated levels of natural radioactivity. The radiation dose rate measured in this mine was about fourteen times higher (1,415 +/- 28 nGy h(-1)) than the average value obtained in northern Tanzania (98 nGy h(-1)). The high average activity levels of phosphate (5760 +/- 107 Bq kg(-1) for 261Ra, 497 +/- 5 Bq kg(-1) for 228Ra, 350 +/- 6 Bq kg(-1) for 228Th, and 280 +/- 5 Bq kg(-1) for 40K) and radiation dose rate recorded show that Minjingu phosphate mine has higher values than the highest radioactivity in phosphate compiled by the United Nations Scientific Committee on the Effect of Atomic Radiation. In view of these findings, a comprehensive risk-management strategy for reduction of radiation risk to the public and mine workers should be put in place. Efforts are currently being made to seek support to improve the background radiation database for subsequent assessment of radiation risk to miners and the societies in the

Browsing by Author "Banzi, Firmi B."

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