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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Measuring global progress towards a transition away from mercury use in artisanal and small-scale gold mining

Koekkoek, Brenda 05 February 2013 (has links)
A sustainable global program to reduce mercury use in artisanal and small-scale gold mining (ASGM) will require the demonstration of credible, continuous progress to secure political support and financing, and ultimately achieve success. Focused progress measurement has been lacking to date for ASGM at the global level. This research analyses information on appropriate options to measure mercury reduction progress in ASGM. Research methods included a case study of Mongolia, supplemented with information analyzed from semi-structured interviews related to ASGM and other applicable evaluation approaches. The study concludes by proposing the development of a framework approach for measuring progress and by offering guiding principles and recommendations. Recommendations for the framework approach include: on-going and enhanced support to an information database; simplified evaluation metrics for the ASGM Partnership; tracking the level of political commitment of national governments as an indicator of progress; and promoting common reporting metrics across global programming.
2

Évaluation de l’exposition populationnelle aux métaux et métalloïdes issus de l’extraction minière artisanale d’or au Mali

Diarra, Zeïnaba 04 1900 (has links)
L'exploitation artisanale de l'or peut libérer des éléments métalliques dans l'environnement, ce qui peut entraîner des expositions professionnelles et environnementales. Cette étude pilote visait à évaluer l'exposition aux métaux et métalloïdes chez les travailleurs d'une mine d'or artisanale, les habitants d'un village minier et les habitants d'un village non minier au Mali par une biosurveillance multiéléments. Un échantillonnage par convenance de 315 personnes a été réalisé, réparti de manière égale dans chaque localité (105 par site) et stratifié par groupe populationnel (hommes adultes, femmes adultes et personnes âgées de moins de 18 ans). Des échantillons d'ongles d'orteils et d'ongles de doigts ont été prélevés sur chaque participant de ces différents groupes et 21 éléments (argent, aluminium, arsenic, baryum, béryllium, cadmium, cobalt, chrome, cuivre, fer, gallium, lithium, manganèse, nickel, plomb, sélénium, strontium, thallium, uranium, vanadium et zinc) ont été quantifiés dans ces matrices par spectrométrie de masse avec plasma à couplage inductif (ICP-MS). Les résultats ont montré que les concentrations de 12 éléments dans les ongles des doigts ou des orteils (en particulier l’arsenic, le cobalt et le cuivre à la fois dans les ongles des doigts et des orteils) étaient plus élevées dans le groupe des travailleurs de la mine par rapport aux groupes des villages miniers et non miniers. Dans le groupe des travailleurs de la mine en particulier, les concentrations d’arsenic dans les ongles des mains et des pieds étaient significativement plus élevées chez les hommes. Les concentrations d’arsenic dans les deux matrices étaient également significativement plus élevées chez les fumeurs par rapport aux non-fumeurs. Les concentrations de nickel, strontium et zinc dans les ongles des doigts et des orteils étaient statistiquement plus élevés chez les femmes que chez les hommes. La plupart des métaux présentaient également une forte corrélation positive dans l’ensemble. Au vu des résultats, il serait pertinent d'étendre cette étude en incluant une évaluation de l'exposition par biosurveillance humaine avec d'autres matrices biologiques telles que le sang et l'urine, couplée à des évaluations environnementales pour mieux identifier d'autres sources potentielles d'exposition tout en tenant compte des facteurs de confusion potentiels et pour comparer les résultats obtenus aux normes internationales. Mots-clés : Exploitation minière artisanale et à petite échelle de l'or, biosurveillance humaine, ongles des orteils, ongles des doigts. / Artisanal gold mining can release metallic elements in the environment that can result in occupational and environmental exposures. This pilot study aimed to assess exposure to metals and metalloids in artisanal gold mine workers, inhabitants of a mining village and inhabitants of a non-mining village in Mali by multi-element biomonitoring. A convenience sampling of 315 individuals was performed equally distributed in each location group (105 per location) and stratified by populational group (adult males, adult females, and people <18 years). Toenail and fingernail samples were collected from each participant of these different groups and twenty-one elements (silver, aluminum, arsenic, barium, beryllium, cadmium, cobalt, chromium, copper, iron, gallium, lithium, manganese, nickel, lead, selenium, strontium, thallium, uranium, vanadium, and zinc) were quantified in those matrices by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that concentrations of 12 elements in fingernails and/or toenails (in particular arsenic, cobalt, and copper both in toenails and fingernails) were higher in the mine worker group compared to the mining and non-mining village groups. In the mine worker group specifically, arsenic concentrations in both fingernails and toenails were significantly higher in males. Arsenic concentrations in both matrices were also significantly higher in smokers compared to non-smokers. Nickel, strontium and zinc concentrations in both fingernails and toenails were statistically higher in females than in males. Most metals also had a strong positive correlation overall. In view of the results, it would be relevant to extend this study by including a human biomonitoring exposure assessment with other biological matrices, such as blood and urine, coupled with environmental assessments to better identify other potential sources of exposure while accounting for potential confounders and to compare the results obtained to international standards. Keywords: Artisanal and small-scale gold mining, human biomonitoring, toenails, fingernails
3

Identifying strategies for effective artisanal and small-scale gold mining interventions in Kadoma-Chakari, Zimbabwe

Metcalf, Stephen Merrick 11 1900 (has links)
This thesis examines historical and contemporary artisanal and small-scale gold mining (ASGM) in Kadoma-Chakari, Zimbabwe in order to identify effective strategies to reduce mercury loss and exposure and to increase miners’ incomes by improving gold recoveries. Cyanidation of mercury-rich tailings and the use of nitric acid to leach mercury from cathode sludge and amalgams are identified as significant pathways for losses of mercury into the environment in Zimbabwe. Indirect evidence suggests that as much as 90% of the mercury contained in amalgamation tailings at mills in Kadoma-Chakari is dissolved during passive vat cyanidation. Mercury traps placed after copper amalgamation plates and centrifuges could reduce the amount of mercury subjected to cyanidation, but mercury can be kept out of cyanidation circuits altogether by replacing whole ore amalgamation with vinyl loop carpets. The optimal cyanide concentration for passive vat leaching is between 0.1 to 0.15%. Better management of nitric acid waste solutions can also significantly reduce mercury losses. The current political and socio-economic crisis significantly limits the effectiveness of ASGM programs in Zimbabwe. Nevertheless, strategies for more effective management of ASGM interventions are suggested by a review of the history of didactic theatre (Theatre for Development) in Africa. Theatre used as an awareness building tool is exemplified by “Nakai”, a drama produced in Kadoma-Chakari to increase knowledge of the hazards of mercury use. Theatre can also be a means to ensure horizontal communication between donors and project beneficiaries if it is used to stimulate discussions that give communities a real voice in development programs. It is proposed that community participation in project design, implementation and evaluation increases the likelihood of project success and sustainability because community-identified problems and solutions are more realistic than those defined by donors, and because community “buy in” and ownership increases pressure on project administrators to deliver the services communities need.
4

Identifying strategies for effective artisanal and small-scale gold mining interventions in Kadoma-Chakari, Zimbabwe

Metcalf, Stephen Merrick 11 1900 (has links)
This thesis examines historical and contemporary artisanal and small-scale gold mining (ASGM) in Kadoma-Chakari, Zimbabwe in order to identify effective strategies to reduce mercury loss and exposure and to increase miners’ incomes by improving gold recoveries. Cyanidation of mercury-rich tailings and the use of nitric acid to leach mercury from cathode sludge and amalgams are identified as significant pathways for losses of mercury into the environment in Zimbabwe. Indirect evidence suggests that as much as 90% of the mercury contained in amalgamation tailings at mills in Kadoma-Chakari is dissolved during passive vat cyanidation. Mercury traps placed after copper amalgamation plates and centrifuges could reduce the amount of mercury subjected to cyanidation, but mercury can be kept out of cyanidation circuits altogether by replacing whole ore amalgamation with vinyl loop carpets. The optimal cyanide concentration for passive vat leaching is between 0.1 to 0.15%. Better management of nitric acid waste solutions can also significantly reduce mercury losses. The current political and socio-economic crisis significantly limits the effectiveness of ASGM programs in Zimbabwe. Nevertheless, strategies for more effective management of ASGM interventions are suggested by a review of the history of didactic theatre (Theatre for Development) in Africa. Theatre used as an awareness building tool is exemplified by “Nakai”, a drama produced in Kadoma-Chakari to increase knowledge of the hazards of mercury use. Theatre can also be a means to ensure horizontal communication between donors and project beneficiaries if it is used to stimulate discussions that give communities a real voice in development programs. It is proposed that community participation in project design, implementation and evaluation increases the likelihood of project success and sustainability because community-identified problems and solutions are more realistic than those defined by donors, and because community “buy in” and ownership increases pressure on project administrators to deliver the services communities need.
5

Identifying strategies for effective artisanal and small-scale gold mining interventions in Kadoma-Chakari, Zimbabwe

Metcalf, Stephen Merrick 11 1900 (has links)
This thesis examines historical and contemporary artisanal and small-scale gold mining (ASGM) in Kadoma-Chakari, Zimbabwe in order to identify effective strategies to reduce mercury loss and exposure and to increase miners’ incomes by improving gold recoveries. Cyanidation of mercury-rich tailings and the use of nitric acid to leach mercury from cathode sludge and amalgams are identified as significant pathways for losses of mercury into the environment in Zimbabwe. Indirect evidence suggests that as much as 90% of the mercury contained in amalgamation tailings at mills in Kadoma-Chakari is dissolved during passive vat cyanidation. Mercury traps placed after copper amalgamation plates and centrifuges could reduce the amount of mercury subjected to cyanidation, but mercury can be kept out of cyanidation circuits altogether by replacing whole ore amalgamation with vinyl loop carpets. The optimal cyanide concentration for passive vat leaching is between 0.1 to 0.15%. Better management of nitric acid waste solutions can also significantly reduce mercury losses. The current political and socio-economic crisis significantly limits the effectiveness of ASGM programs in Zimbabwe. Nevertheless, strategies for more effective management of ASGM interventions are suggested by a review of the history of didactic theatre (Theatre for Development) in Africa. Theatre used as an awareness building tool is exemplified by “Nakai”, a drama produced in Kadoma-Chakari to increase knowledge of the hazards of mercury use. Theatre can also be a means to ensure horizontal communication between donors and project beneficiaries if it is used to stimulate discussions that give communities a real voice in development programs. It is proposed that community participation in project design, implementation and evaluation increases the likelihood of project success and sustainability because community-identified problems and solutions are more realistic than those defined by donors, and because community “buy in” and ownership increases pressure on project administrators to deliver the services communities need. / Applied Science, Faculty of / Mining Engineering, Keevil Institute of / Graduate

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