Entanglements and disentanglements : a posthuman approach to mercury use in artisanal and small-scale gold mining in Antioquia, Colombia : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Social Anthropology at Massey University, Palmerston North, New Zealand

This research uses qualitative research techniques and posthuman theories to investigate the dynamic relationship between artisanal and small-scale gold miners and mercury in the context of Antioquia, Colombia. This is done to contribute to understandings of, and inform potential solutions for, the global environmental problem that is mercury pollution from artisanal and small-scale gold mining (ASGM). Miners come to know mercury through practices, and through these practices, mercury comes to be co-constitutive of an informal ASGM industry. Mercury provides an easy yet profitable mode of gold extraction with limited capital expenditure. Eliminating the use of mercury means a re-constitution of ASGM as a formal industry with higher levels of capital investment, new actors and a shift to a more representational approach to knowing materials. The use of toxic mercury and an increase in the enforcement of mining legislation are framing miners as illegal. Formal, responsible mining is becoming a dominant reality, and informal miners who resent being labelled illegal are working to transition to this reality. Miners’ experiences of this transition vary greatly, and this variation can be explored through the lens of ecological habitus. Many miners are using mercury elimination to perform good citizenship by mining responsibly, introducing a performative aspect to formalisation. Nevertheless, miners still face significant challenges to formalisation. As a result, many miners have had to become subcontractors for large-scale mining companies, entering exploitative relationships with which mercury, through its absence, is complicit. Taking this approach towards understanding the relationship between miners and mercury has helped to resolve the conflict between material and social deterministic views of the practice of mercury use, and linked mercury to a wider political context, which is a necessary consideration for a collaborative approach with miners to eliminate mercury. Keywords: Artisanal and small-scale gold mining; ASGM; mercury; Colombia; anthropology; posthumanism; entanglements; politics of materiality; performativity; informality

Mercury or Mercury Free Restorations in Oral Cavity

Amalgam is basically a concoction of metals that has been used as a potent filling material in dentistry for the last 150 years. Amalgam usually consists of silver, mercury, tin and copper. Dental amalgam is a material used to fill cavities of tooth. Over the years, amalgam has become a topic of concern because it contains mercury. Mercury is a naturally occurring metal in the environment. Mercury exists as a liquid in room temperature but when heated, it becomes a gas. Flexibility of amalgam as a filling material is due Mercury. An alloy powder, a compound that is soft in nature when mixed with mercury makes it enough to mix and condense into the tooth. It hardens quickly and offers strong resistance to the forces of biting and chewing. There are studies reported on the safety of amalgam fillings. In 2005, European Union launched a comprehensive mercury strategy to reduce use of mercury. In 2008, countries like Norway and Denmark restricted the use of dental amalgam containing mercury. In 2009, this research was evaluated by U.S. Food and Drug Administration (FDA) and found no rationale to limit the use of amalgam. There are certain restorative materials that are available commercially that are mercury free in nature like Gold, Porcelain, Gallium alloys, Composite resin restoratives etc. They offer many advantages over amalgams containing mercury like: seals the dentin from future decay, reinforces remaining tooth structure, provides smooth and bonded margins, conservative and it blends naturally

High mercury emission (both forms: Hg0 and Hg2+) from the wet scrubber in a full-scale lignite-fired power plant

The paper describes and discusses the results of research on mercury behaviour, especially its high emission, in both forms: elemental (Hg-0) and oxidised (Hg2+) from the wet flue gas desulphurisation scrubber (WFGD) in a lignite-fired power plant located in central Europe. The presented results involve the collection of lignite power plant samples (liquid, solid, gas) and different laboratory chemical analyses to try to understand the mechanism of mercury re-emission from the wet flue gas desulfurization system. It was noted that 67-80% of the total inlet mercury concentration left the WFGD scrubber. Moreover, the oxidised form of mercury was the main emitted form (about 60-70% of the total mercury concentration). The results show that mercury was found in very high concentration (10 mu g/g) (range: ppm) in the WFGD solid by-products, whereas the liquid phase contained only 1 mu g//l (range: ppb). Considering literature reports and presented data from the investigated power station, we believe that iron (Fe), which occurs in very high concentrations in solid WFGD samples (1.81% wt. Fe) and lignite (up to 20 g/kg Fe) is mainly responsible for disrupting the mercury absorption in the scrubber, the partitioning of the mercury between phases and leads to its reemission. Moreover, we believe also that a relatively high iodine ion concentration (130 mg/l) in the limestone slurry leads to mercury emission in its oxidised form, mainly as Hgl(2), which is highly volatile. Other minor components from limestone dissolution such as Mn, Al and Mg may additionally enhance that "complex" mercury behaviour.Web of Science270art. no. 11749

An Ethnography of Entanglements: Mercury’s Presence and Absence in Artisanal and Small-scale Gold-mining in Antioquia, Colombia

This paper describes a ‘follow the thing’ methodology as applied to an ethnography of entanglements. This methodology allowed for a materially and politically nuanced understanding of Antioquia, Colombia’s response to mercury pollution. This pollution primarily originates from the Artisanal and Small-Scale Gold Mining (ASGM) industry where mercury is employed in the gold extraction process. In following the mercury, the authors experiment with an ethnography of entanglements. The paper discusses how they address the current lacunae in mining ethnographies by focussing on mining as ‘practice’, going past the provision of technical descriptions of mining and ethnographic descriptions of miners to an ethnography of mining. This ethnographic approach considers the politics of materiality and addresses a lack of attention to the impacts of the presence and absence of materials on social life. Various mining practices in Antioquia illuminate how entanglements between miners and mercury have been co-constitutive of particular modes of ASGM. The paper will also provide examples of ‘negative mercury entanglements’ where efforts have been made to extricate mercury from mining practices. Rather than creating a vacuum, these mercury absences have been generative of new contested symbolic and material arrangements including entrepreneurial and ‘responsible’ mining, debates over miners’ rights, and the creation of new political relationships between ASGM and large-scale mining companies.fals