| 1. |
- Diosana, Joseph A.L., et al.
(author)
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Strategies on reducing mercury use and exposure in small-scale gold mining -- experiences from Mt Diwata, the Philippines.
- 2006
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In: Abstracts of Eighth International Conference on Mercury as a Global Pollutant. - 1932078657 ; , s. 574-
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Conference paper (other academic/artistic)abstract
- The discovery of gold 1983 in the unpopulated Mt Diwata, the Philippines, resulted in that the mountain within a few years became populated with up to 200 000 persons, making their living from gold extraction. The methods used, amalgamation with mercury and cyanide leaching with rudimentary equipment, result in large emissions of mercury and cyanide and related deterioration of environment and health. Our objective is to relateobservations made in 2005 in relation to mercury supply and use in Mt Diwata and propose possible actions to reduce the deterioration of health and environment. There are no reliable records on Hg actually used or emitted in Mt Diwata. In 2004, theEnvironmental Management Bureau in Davao City certified 367 tonnes Hg for the enduse of mining in Mt Diwata. The quantities actually used were much smaller, but not registered. Sales from authorized Hg dealers in neighboring cities and smuggled Hg, notably via Indonesia, complicates the inventory. Based on documents, interviews, package labels, and quantities of gold extracted, the following observations were made.The consumption of Hg for gold mining has decreased by up to 50% since 2003 as a result of the increased Hg price. Still, more than 10 t Hg is annually used for gold mining in Mt Diwata. A significant fraction of this originates from the EU, notably the Spanish state company MAYASA. The continued use of Hg is not technically or economicly motivated, because amalgamation recovers only a minor part of the gold available, resulting in subsequent cyanide treatment of the ore. Moreover, the cyanide leaching is less efficient on amalgamated ores. Magnetic sluices could replace Hg for partial recovery of gold before submission of the ore to an environmentally adapted cyanidation process. Economic means in form of credits are necessary to permit investment in safer cyanidation equipment. Information is needed to the miners about safer extraction methods and a general use of retorts could reduce but not eliminate hazardous mercury exposure. Restricting the present Hg supplies from Spain and other countries of the EU and from the USA would intensify the transition to Hg free gold mining methods.
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| 2. |
- Halonen, Riikka, et al.
(author)
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Controlled trade or poison streams to the developing countries?
- 2006
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In: Abstracts of Eighth International Conference on Mercury as a Global Pollutant. - 1932078657 ; , s. 574-
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Conference paper (other academic/artistic)abstract
- Mercury circulates around the globe as a product in international trade and because of releases from natural and anthropogenic sources. Since mercury and its compounds are highly toxic to humans, ecosystems and wildlife, international efforts are being made to reduce its use. Finland is one of the biggest mercury producers in the EU and the biggest one producing virgin mercury. Between 25 and 75 tons mercury as a byproduct frommetal smelting of zinc and copper ores are annually produced in Finland by Boliden Kokkola Ltd, which belongs to the Swedish New Boliden Group.The aim of this FinnWatch study is to bring up problems related to mercury trade and to draw attention to the international trade and development policies. A related aim is to see whether selfcontrol of companies is sufficient or if authority supervision and restrictions are needed. The report is a desk-study, which uses many sources including Global Mercury Assessment of the UNEP and interviews. The FinnWatch study presents mercury production, usage and hazards in general. It focuses especially on Finland's position as a mercury producer and supplier of mercury to small-scale gold mining in the Amazon. Boliden says that it does not want to export mercury outside of Europe. The company says alos that it sells mercury only to suppliers, who resells it only within Europe. However, other sources maintain Finnish mercury has also ended up in developing countries, for example in Brazil, where it can be bought bottled in pharmacies by anyone. It is used without personal protective equipment in small-scale gold mining causing health problems and causes environmental pollution and accidents. The self-control ofmercury trading companies is proving to be inadequate according to the FinnWatch report. The FinnWatch study shows that Finnish mercury may end up in developing countries - or may not, despite Boliden's recently introduced efforts to control its tradeand customs. Further research is needed.
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| 3. |
- Hylander, Lars D., et al.
(author)
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Dental amalgam – the most important point source of mercury pollution in Swedish soils.
- 2006
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In: Abstracts of Eighth International Conference on Mercury as a Global Pollutant. - 1932078657 ; , s. 574-
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Conference paper (other academic/artistic)abstract
- Mercury (Hg) as amalgam has been used as a dental filling material for more than 150 years. Thereby, Hg emits into wastewater from households and dental clinics and into airfrom incinerators and cremation furnaces. Soil and sediment get contaminated via atmospheric deposition and when spreading wastewater sludge as a soil conditioner or at improper dumping in land fills. Banning Hg in dentistry is the only long-term way to stop Hg emissions from dental amalgam. Even with a ban for dental amalgam, immediate actions are needed to reduce emissions from the 1300—2200 tonnes of Hg inserted in EUcitizens (15 countries). These ongoing emissions from dental clinics and cremation furnaces could be efficiently controlled with available technology, while emissions from abrasion due to every day chewing cannot be hindered without large monetary costs. We present actual, national Hg emissions from dental clinics and crematoria in Sweden and compare these emissions with calculated emissions if best available technologies were tobe used. Both technical and economic aspects are addressed. In conclusion, Hg emissions from crematoria could be practically eliminated with only marginal costs, while Hg emissions from dental clinics in Sweden could and must be reduced by more than an order of magnitude to obtain wastewater sludge with Hg levels acceptable in a sustainable context.
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| 4. |
- Lücke, Sofie, et al.
(author)
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Evaluation of a new method using magnetic sluices for mercury-free small-scale gold mining in the Philippines.
- 2006
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In: Abstracts of Eighth International Conference on Mercury as a Global Pollutant. - 1932078657 ; , s. 574-
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Conference paper (other academic/artistic)abstract
- Approximately 100 000 people are involved in small-scale gold mining a in the Philippines. They mainly use the amalgamation and/or cyanidation processes. The use of mercury started in the 1980’s, when the price of gold went up. The workers live in thesame place as they work, they do not use safety equipment and the tailings are generally left anywhere. The concentrations of mercury in drinking water, soils, sediments, tailings and fish near gold mining operations exceed in general national and international limits.The aim of this study was to evaluate a new method for gold recovery, suitable for smallscale miners and in which mercury, cyanide or other chemicals are not used. Interviews with some miners were also performed in order to understand the complex situation from a miner’s perspective and evaluate the possibilities to improve the situation. The gold separation method, Cleangold (US patent granted in July 1999, #5,927,508) is developedby David Plath, USA, and uses magnetism to create riffles in a simple sluice, for a physical separation of gold from grains with lower density. The study was performed at five different sites in the Philippines (Diwalwal, Mainit, Acupan, Balatoc and Paracale).The gold recovery from the different sites varied both between and within the sites. The highest recovery was obtained in Balatoc (73%) and the lowest in Acupan with a top value of 15%. In comparison, the recovery using the amalgamation method is generally between 25 and 50% at the sites and at cyanidation estimated to approximately 90%. The chances of reducing the use of mercury are large, for example by adding mercury in the final step only, while panning, in case the magnetic sluices cannot completely replace amalgamation. In conclusion: the miners want and need a change. The obstacles for development are lack of technology and knowledge, unstable economy, habits and the fact that mercury and cyanide are easily accessible on the market. Further, for development and adaptation of environmentally benign methods, stricter control/legislation and accessible loans/micro credits to the miners are important. Industrial countries could play an important role by transferring appropriate knowledge rather than mercury.
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| 5. |
- Maag, Jakob, et al.
(author)
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"Mercury Substitution Priority Work-list" - An Input to Global Considerations on Mercury Management
- 2006
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In: Abstracts of Eighth International Conference on Mercury as a Global Pollutant. - 1932078657 ; , s. 574-
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Conference paper (other academic/artistic)abstract
- Awareness of proper management of mercury containing products and development of mercury free al-ternatives has over the last decades emerged in many industrialized countries, where mercury was earlier used with no or few restrictions. Recent reviews have shown that suitable alternatives are readily available for most mercury applications in products and processes. This indicates that there is presently a real opportunity to minimize the use of most mercury containing products, and thereby markedly minimize mercury releases. In spite of reductions in mercury consumption in many countries, anumber of applications are still being used on a routine basis with consequent mercury releases through their life cycle - production, use and disposal/recycling - with resulting needs for effort and investment in control initiatives. Many mercury containing products have long lives, meaning that proper life cycle management with separate collection and specific waste treatment will continue to be important even several decades after a potential cessation of introducing mercury containing products on the market. Available evidence also indicates that in some parts of the world, where the pressure for mercury substitution has been weaker, mercury containing products are still widely used. This presentation discusses the need for continued efforts addressing intentional mercury use in products and processes on a global market, and provides - based on an expert assessment - the authors input to a global "Mercury substitution priority work-list" taking into consideration recent reviews of alternatives and examples of existing agreements andnational legislation where prioritizations are made. This is done in the hope of initiating and informing a discussion of a common vision for mercury substitution, bridging national and regional differences. The substitution priority list is a contribution to current global discussions of measures to reduce mercury releases.
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| 6. |
- Miranda, Conrado R., et al.
(author)
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Mercury use and emissions in small-scale gold mining in southeastern Mindanao, Philippines and the need for intervention.
- 2006
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In: Abstracts of Eighth International Conference on Mercury as a Global Pollutant. - 1932078657 ; , s. 574-
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Conference paper (other academic/artistic)abstract
- There are several small-scale gold mining operations scattered throughout the Philippine archipelago occupying about 50,000 miners and mineral processors. The sites with the larger number of miners involved are located in Southeastern Mindanao, Philippines, particularly in Compostela Valley Province. Our objective is to relate observations made in relation to mercury use in small-scale gold mining in the Philippines. Although the useof cyanide has been introduced, mercury amalgamation for gold recovery is still, in a number of operation sites, the dominating method. Amalgamation tailings (aside from unprocessed ore) are generally further processed in a cyanidation plant because most gold is left after amalgamation. Amalgamation and cyanidation tailings are usually dumped into improvised, generally leaking, dams or directly in the surroundings. Mercury is thus released into the environment by direct disposal or seepage into rivers and unconfined blow torching of mercury amalgam. There is no complete record or inventory of mercury importation for use in small-scale gold mining operations. Amounts of mercury releasedare not documented and reliability of estimates is poor. Recovery and recycling of mercury has not been commonly practiced because the efforts are not commensurate to any large monetary savings, although there is presently an increasing interest in economizing mercury use as an effect of increased mercury prices. Records of high levels of mercury in sediments and waters within and downstream mining areas indicate significant releases of mercury. It has been estimated that 50 tons of mercury might have been released annually into the rivers in the Diwalwal gold-rush area, the largest smallscale mining operation in Mindanao, at the height of the gold rush from 1986-1988. Releases declined then to 26 tons annually, which was further reduced to 17 tons annually in the past two years. These emissions threaten the ecosystem as well as the workers and their families, also in communities downstream. Therefore education campaigns, global initiatives to restrict mercury availability and a continuous strict enforcement of existing regulations on mercury use must be prioritized to reduce theareas and the numbers of individuals affected by mercury pollution.
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| 7. |
- Ninomiya, Tadashi, et al.
(author)
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Preliminary results from diagnosis of nervous damages at Mt Diwata in 2005.
- 2006
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In: Abstracts of Eighth International Conference on Mercury as a Global Pollutant. - 1932078657 ; , s. 574-
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Conference paper (other academic/artistic)abstract
- Few studies have reported health effects from mercury vapor released at gold mining when using the amalgamation method. This is because the mining sites are often newly developed, without authorization, located far away and the miners have limited awareness on health risks and weak capacity to request relevant studies. Negligible tax returns from small-scale miners limit possibilities to allocate medical resources to their sites. An example is Diwalwal, Mt Diwata in the southern Philippines, where just one medical doctor serves a mining community with about 20 000 inhabitants, including 1200 school children. Therefore he is limited to carry out the most urgent medical care and have no time to diagnose potential health effects of several tonnes of mercury annually emitted in the village. The main aim of this study was to estimate the extent of nervous damages among the population in a small-scale mining village. Another aim was toevaluate a set of diagnosing methods for nervous damages and to judge whether employing just one or two of them may give an accurate diagnosis, eventually performed by staff having limited medical training. The study was performed in Mt Diwata, havingabout 300 mills with subsequent mercury amalgamation. In August 2005, 66 persons, predominantly men, were examined for eventual neurological damages. The persons were the same as had been sampled for blood and hair in February 2005 and analyzed for Hg concentrations, which will be reported elsewhere. Staff at two offices in Davao City, situated four hours drive from Mt Diwata, were also examined and served as a reference group. The examinations revealed that nobody in the reference group was diagnosed for neurological damages, while some cases were confirmed in Mt Diwata, predominantlypersons burning amalgam. In spite of this, we do not recommend a general introduction of protective masks with mercury trapping filters to amalgam burners, because this will not protect the children, being most vulnerable. In conclusion: a brain damaged by mercury vapor cannot be healed, so industrialized countries should transfer appropriate knowledge and mining technology rather than mercury, as presently done, to Mt Diwata.
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| 8. |
- Shafer, Kristina, et al.
(author)
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Novel solution to reduce or eliminate mercury pollution from artisanal and small scale gold mining.
- 2006
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In: Abstracts of Eighth International Conference on Mercury as a Global Pollutant. - 1932078657 ; , s. 574-
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Conference paper (other academic/artistic)abstract
- In Suriname, mercury amalgamation is the favored method for recovering fine gold from sluice concentrates. An estimated 12-16,000 miners are releasing as much mercury to the environment as they are recovering in gold. A project is now underway to reduce or eliminate the use of mercury in gold mining. Funded by World Bank and in partnership between Artminers and World Wildlife-Guianas, this project introduces the Cleangold™sluice as an alternative to mercury. This patented method employs simple, inexpensive gravity separation. The University of British Columbia and University of Uppsala in Sweden have independently verified the efficacy of Cleangold. After field tests in Africa, Asia and South America, UNIDO’s Global Mercury Project has identified Cleangold as a mercury replacement method. A first round of training workshops were completed inDecember 2005 with over 70 miners attending. Interest is high in Cleangold because miners are paying upwards of $300/kg for mercury. Testing the ores and tailings of the operations in two areas confirmed anecdotal accounts from miners that they arerecovering approximately 50% of the gold using their current practices. Using the Cleangold method, samples of gold, mercury, and amalgamated gold were recovered from tailings. The bulk of the gold recovered was found to be less than 150 microns indiameter. While the sluice boxes used by these miners are well built and operated, gold below 150 microns is not recovered by their expanded metal and looped carpet sluices. Evidence of losses of gold larger than 150 microns during the amalgamation process was noted and a mechanism for this loss is suggested. Methods to completely remove the use of mercury from these operations are described. Miners who attended workshops intendto employ Cleangold sluices to retrieve mercury, amalgam and fine gold from their tailings. This will be the first step in reclamation of abandoned mine sites. To reduce pollution from this process, WWF-Guianas will build simple retorts for distribution to miners to safely recover mercury from the concentrates of the Cleangold™ process until mercury free mining is established.
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| 9. |
- Sokolik, Adrian S., et al.
(author)
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Mercury concentrations in sediment and fish from Nanay River, Peru – a small-scale gold mining area.
- 2006
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In: Abstracts of Eighth International Conference on Mercury as a Global Pollutant. - 1932078657 ; , s. 574-
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Conference paper (other academic/artistic)abstract
- Nanay River in the peruvian Amazonian rain forest supports 300 000 inhabitants in the city of Iquitos and surrounding villages with drinking water and fish for consumption. The river has been polluted with mercury, due to the use of the amalgamation method for gold extraction. This has resulted in that local people have got increased levels of mercury, up to 45 mg mercury per litre of blood. The aim of this study was to evaluate the concentrations of mercury in sediment and fish in the Nanay River, Peru, and to study eventual relation between fish mercury concentrations and mercury concentrations in sediment and water parameters such as dissolved organic matter, pH, dissolved oxygen and turbidity. In October 2005, eleven sample points for river water and sediment were established, from the gold mining activities close to Pucaurco westwards (18M 0605010, UTM 9579526) to Pampa Chica eastwards, drinking water source for Iquitos, (18M 0691053, UTM 9585255) in the region Loreto in Peru. Water temperature, conductivity,total dissolved ions, turbidity, dissolved oxygen and pH was measured in the field. Five species of predatory fishes were collected within the study area, where Pintuyacu Riverjoins Nanay River. The samples are currently subject to analyses in Sweden and results will be obtained during the spring. Based on the results, information will be sent to the Regional Government in the region of Loreto about the current state and recommended actions to prevent further contamination.
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