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This paper aims to investigate the level of pollution of water, sediment, and soil due to semimechanized artisanal gold mining in Béké, Adamawa region of Cameroon. For this purpose, water and sediment samples were collected and analyzed. In order to achieve this goal, several research studies and field observations were carried out. Questionnaires were also used to complement field investigations. All these enabled the identification of the potential sources of impacts on the human, physical, and biological environment. Three soil samples (S1, S5, and S7) were collected on the same spot with the water sample and analyzed to assess the intensity of soil contamination. The water samples (W1–S9) were characterized physically, chemically, and microbiologically to evaluate the water quality contamination. The results of the physicochemical analysis of the water samples showed that the rivers in this zone are moderately acidic (with pH values ranging from 5.11 to 6.37) and slightly mineralized (with sample W2 collected from the Béké river having an iron concentration of 6.7 g/L). The pattern of mean trace metal concentration in sediments was Fe > Mn > Cr > Pb > Cu > Zn. According to pollution indices, the contamination degree (CD) varied from 4.03 to 4.56 corresponding to low contamination. The index of ecological risk ( E r i ) for all the trace metals was low ( E r i ≤ 40) and the geoaccumulation index (Igeo) ranged between uncontaminated and moderately contaminated (Igeo 0-1). The result of our field investigations and analysis shows that the semimechanized artisanal gold mining in the locality of Béké has very significant environmental consequences such as land degradation, deforestation, water pollution, and landscape modification. [ABSTRACT FROM AUTHOR]

The red microalga Galdieria sp. is an extremophile that inhabits acidic hot sulphur springs and grows heterotrophically to a high cell density. These characteristics make Galdieria suitable for commercial applications as stable mass production is the key to success in the algae business. Galdieria has great potential as a precious metal adsorbent to provide a sustainable, efficient and environmentally benign method for urban mining and artisanal small-scale gold mining. The efficiency and selectivity in capturing precious metals, gold and palladium from metal solutions by a Galdieria-derived adsorbent was assessed relative to commercially used adsorbents, ion exchange resin and activated charcoal. As it is only the surface of Galdieria cells that affect metal adsorption, the cell content was analysed to determine the manner of utilisation of those metabolites. Galdieria was shown to be protein-rich and contain beneficial metabolites, the levels of which could shift depending on the growth conditions. Separating the cell content from the adsorbent could improve the adsorption efficiency and reduce CO2 emissions during the metal collection process. The commercial applications of Galdieria appear promising: growth is quick and dense; the precious metal adsorption capacity is highly efficient and selective in acidic conditions, especially at low metal concentrations; and the cell content is nutrient-rich. [ABSTRACT FROM AUTHOR]

Various sensors and electronic devices are recently developed to monitor human health in mechanically flexible or even stretchable forms for intimate contact with non‐flat curvilinear surfaces of the human body. For successful operation of these devices, finding a proper way to electrically power them is very important. In this work, glucose/oxygen fueled enzymatic biofuel cells (EBFCs) based on microfluidic structured elastomeric polydimethylsiloxane substrate with wrinkled gold (Au) electrodes are suggested for power supply. For doing that, firstly, bottom surface of microfluidic channel is covered with buckled Au electrodes for stretchability. By microfluidic design showing capillary imbibition through fluidic channels, loading of catalyts is promoted. Interestingly, buckled Au electrodes induce much better anodic and cathodic reaction rates than those of non‐buckled Au electrodes by 25% and 33%, respectively. This is because surface area and the amount of catalyst loading in electrodes increase by Au wrinkling. In evaluations of EBFCs using the buckled Au electrodes, maximum power density reaches 7.1 ± 0.64 µW cm−2, while they show decent performance of 5.4 ± 0.49 µW cm−2 even under external stretching. Taken together, it is corroborated that such proposed stretchable EBFCs are alternative for providing electrical power in wearable or implantable devices. [ABSTRACT FROM AUTHOR]

In the first years of the 18th century, the captaincy of Mato Grosso was the scene of countless gold discoveries, the lives of its inhabitants were marked by the continuous arrival of waves of men and women who sought to improve the conditions for their existence. Several elements were responsible for the formation of a plural and diverse society than the Portuguese Metropolis. The insufficiency of resources and products forged new practices and customs different from those existing in the Kingdom. Remember that these settlers were exploring the backlands that had never been explored before. Thus, the social organization of the Captaincy of Mato Grosso was highlighted by a social stratification made up of whites, blacks, mulattos, free and captives and by a new social layer to be conquered, the indigenous. The initial foundation of the cities in Mato Grosso had the objective of protecting the Portugal domains on the border with the Spanish. The difficulty in populating the Captaincy forced the Crown to grant special benefits and privileges to sertanists who took the risk of settling in the Captaincy, this included the indigenous nations that lived there Arraiais Towns and Cities were forged in order to meet the demands imposed by the geopolitics of the region. [ABSTRACT FROM AUTHOR]

Latin America is framed within a neoliberal rationality that favors the installation of legal structures of dispossession (LSD) (Hernández, 2019). However, local communities resist and counterattack in diverse ways, including legal and political. A space for observing these dynamics is the socioenvironmental conflict derived from the La Colosa gold mining project in Colombia, since, through the use of mechanisms such as popular consultation, new institutional agreements have been reached challenging the traditional distribution of power over the territory. The central argument is that the case of resistance to megaprojects through legal mechanisms helps to observe the processes of institutionalized resistance that transform legal structures to give way to a different relationship between nature-society. Methodologically, the argument is based on participant and participatory observation, semi-structured interviews, documentary, and journalistic review between 2013 and 2022, and review of judicial documents from a documentary ethnography perspective (Muzzopappa & Villalta, 2013). Despite the asymmetry of power in which socio-environmental disputes develop, the results show that there are multiple interactions challenging the hegemonic power from the local level, forcing it to a permanent territorial reflexivity. In addition, it is based off the responses from organized communities, public authorities, and corporations that the strategies for the following stages of the conflict arise. This implies that any conflict is not beforehand resolved. [ABSTRACT FROM AUTHOR]

The Chinese Question is about the origins of Chinese diasporic communities in the West; the rise of the racist movements and exclusion legislation passed against them; and the struggles of the Chinese emigrants for respect and equal treatment, both in China itself and in the international community. Chinese exclusion policies across the Anglo-American world showed the importance of domestic racism in the formation of nation-state identities. At another level, they were also integral to the development of the late nineteenth century ascent of Great Britain and the U.S. as global economic hegemons, as creditors and as colonizers, as nation builders and as empire builders. Because China was never formally colonized, the Western powers imposed unequal treaties and exclusion laws as instruments of colonialism and containment. Exclusion policies were integral dynamics of colonialism and capitalism; part of a new way of imagining, organizing, and governing the world. [ABSTRACT FROM AUTHOR]

This article considers the broad question of how to improve the conditions of workers in artisanal and small‐scale gold mining (ASGM), which relies on predominantly informal activities. While acknowledging that formalization can provide ASGM miners with tenure security and protection of labour rights, it is important to highlight that not all workers are likely to benefit from formalization in the same way, and that decent work ambitions should extend to all workers, regardless of whether or not they are formalized. It is therefore crucial to understand the heterogeneity in the ASGM workforce. This article describes working conditions for different categories of workers based on a survey carried out in the Watsa and Shabunda territories in Eastern Democratic Republic of Congo. It analyses labour agency and shows that workers are diversely integrated in the labour process and may use power resources in various ways. The discussion reflects on ways to consider the heterogeneity in ASGM labour and to push the ASGM agenda beyond formalization. [ABSTRACT FROM AUTHOR]

Despite the introduction of the perimeter blasting technique at the Tulawaka Gold Mine, the mine continued to suffer from an overbreak of mine development headings, with an average overbreak of 24% every 22 m, which is approximately twice the acceptable 10% overbreak. The causes of this problem include ineffective drilling practices and uneven and excessive charging of explosives, resulting in a slightly high powder factor of 3.94 kg/m3 instead of 3.8 kg/m3, as per the design. The problem of overbreak resulted in ore dilution, a longer mine development cycle time and additional costs of approximately US$ 45 per cut, especially in mucking and hauling processes. This study proposed and recommended new drill and blast designs to solve this problem. Compared to the existing design, the proposed new drill design has a total of 12 fewer drill holes; this is a significant number of holes, which significantly reduces drilling costs. The proposed new blast design consumes approximately 25 kg less ANFO than the existing practice. Moreover, the study showed that large drives in the Star and Comet in the Geita Gold Mine suffer the most from the problem of ineffective advance per cut. One of the causes of ineffective advances per cut is the low amount of explosives used per cut compared to the planned amount. [ABSTRACT FROM AUTHOR]

Mercury is a ubiquitous environmental contaminant and can be found in inorganic (Hg0, Hg+ and Hg2+) and organic forms (chiefly CH3Hg+ or MeHg+). The main route of human, mammals and bird exposure occurs via predatory fish ingestion. Occupational exposure to Hg0 (and Hg2+) can also occur; furthermore, in gold mining areas the exposure to inorganic Hg can also be high. The toxicity of electrophilic forms of Hg (E+Hg) is mediated by disruption of thiol (-SH)- or selenol (-SeH)-containing proteins. The therapeutic approaches to treat methylmercury (MeHg+), Hg0 and Hg2+ are limited. Here we discuss the potential use of ebselen as a potential therapeutic agent to lower the body burden of Hg in man. Ebselen is a safe drug for humans and has been tested in clinical trials (for instance, brain ischemia, noise-induce hearing loss, diabetes complications, bipolar disorders) at doses varying from 400 to 3600 mg per day. Two clinical trials with ebselen in moderate and severe COVID are also approved. Ebselen can be metabolized to an intermediate with -SeH (selenol) functional group, which has a greater affinity to electrophilic Hg (E+Hg) forms than the available thiol-containing therapeutic agents. Accordingly, as observed in vitro and rodent models in vivo, Ebselen exhibited protective effects against MeHg+, indicating its potential as a therapeutic agent to treat MeHg+ overexposure. The combined use of ebselen with thiol-containing molecules (e.g. N-acetylcysteine and enaramide)) is also commented, because they can have synergistic protective effects against MeHg+. [ABSTRACT FROM AUTHOR]

Gold deposits in Precambrian cratons were mostly generated during the formation and stabilization of the cratons, but the North China craton is unusual in that its gold deposits were mainly formed ~1.7 b.y. after its stabilization. A magmatic-hydrothermal origin or mantle-derived fluid source has been proposed for the giant gold deposits of the Jiaodong District in the eastern North China craton, but direct evidence is sparse, and the mineralization processes remain controversial. Here, we present the results of a comprehensive geological, geochronological, and geochemical study of the gold mineralized Xiejia diorite beneath the Linglong ore field at Jiaodong to link the gold mineralization to underlying magmatism. Magmatic zircon and titanite grains from the Xiejia diorite have laser ablation--inductively coupled plasma--mass spectrometry (LA-ICP-MS) U-Pb ages of 121.3 ± 0.9 Ma to 120.8 ± 1.1 Ma and 121.7 ± 3.9 Ma, respectively, which are indistinguishable from the time of gold deposition throughout the Jiaodong District as constrained by previous studies. The diorite has a shoshonitic composition and is characterized by strong enrichment in large ion lithophile elements (LILEs) and light rare earth elements (LREEs) along with significant depletion in high field strength elements (HFSEs) and heavy rare earth elements (HREEs). Samples of the diorite have high initial 87Sr/86Sr ratios, but low εNd(t) and εHf(t) values and low Pb isotope ratios. These geochemical characteristics are akin to those of contemporaneous mafic dikes in most gold mines at Jiaodong, indicating that the Xiejia diorite was most likely derived from an enriched lithospheric mantle source. The upper part of the diorite intrusion is pervasively altered and mineralized, containing an average of 0.32 g/t Au, but locally up to 7.59 g/t. Hydrothermal titanite from the mineralized diorite has a LA-ICPMS U-Pb age of 122.3 ± 4.3 Ma, which is consistent with the gold-bearing pyrite Re- Os isochron age of 122.5 ± 6.7 Ma. Ore-related sericite aggregates from the Dongfeng gold deposit above the Xiejia diorite have a 40Ar/39Ar plateau age of 122.6 ± 1.3 Ma. Pyrite from the mineralized diorite yielded δ34SCDT values of 2.1‰-9.7‰, which are comparable with those of pyrite (δ34SCDT = 5.8‰-8.1‰, where CDT indicates the Canyon Diablo troilite standard) from gold ores of Dongfeng. Pyrite grains from both groups also have similar Pb isotope compositions. The S and Pb isotope data are consistent with values of mafic dikes that are spatially and temporally associated with gold veins in the Linglong ore field. The results presented here thus indicate a possible genetic link between gold mineralization in the Xiejia diorite and underlying magma presumably represented by the Xiejia diorite. The auriferous fluids exsolved from that magma and migrated upward along the Potouqing fault to form the Dongfeng gold deposit above the Xiejia diorite. The mineralized diorite thus links shallow gold mineralization to deep-seated mantle-derived magmatism generated during the extensive destruction of the North China craton induced by the rollback of the subducted paleo-Pacific plate. [ABSTRACT FROM AUTHOR]

A rise in human disturbance in Comoé National Park (CNP) has led to lion (Panthera leo) extirpation. After the crisis, there have been numerous efforts to restore this ecosystem and CNP's management authority is considering reintroducing lions. This ideally requires an understanding of the earlier process of lion extirpation. We assessed the causes of lion extirpation through semi-structured questionnaires to 307 volunteer participants in surrounding 23 villages. Respondents reported that lions were extirpated two decades ago (19.75 years ± 8.15). Bouna was the sector that lions seem to have disappeared first (mean = 23.61 years± 9.14) and recently on Nassian and Téhini sectors (mean = 18.43 years ± 8.17 and 18.74 years ± 6.74 respectively). People identified civil war from 2002 as the main facilitator of lion extirpation (85%; n = 261), which led to the abandonment of CNP, and opened the way for all forms of anthropogenic pressures including illegal hunting and prey depletion (70%; n = 216), illegal gold mining (74%; n = 227), direct lion killing due to transhumance and human-wildlife conflict (15%; n = 45), and wildfires (23%; n = 72). Historically, prey density curves show a progressive decrease with a drastic drop during the civil war period before a post-crisis recovery from 2016 to 2022. We recommend intensifying CNP monitoring and local measures to limit anthropogenic disturbances and improve indigenous communities' involvement to ensure the success of potential lion reintroduction. [ABSTRACT FROM AUTHOR]

In recent times, groundwater has emerged as an alternative drinking water source for populations in Ghana's gold mining communities due to high pollution levels in surface water resources caused by artisanal miners. This study presents the findings on different radioactivity levels in groundwater, their sources, the characteristics of aquifers in the study area, and the impact of radionuclides on human health as a factor of water quality. The mean activity concentrations of radionuclides in groundwater samples were 0.1 ± 0.04 Bq/L for Ra-226, 0.36 ± 0.05 Bq/L for Ra-228, and 1.41 ± 0.10 Bq/L for K-40. The activity concentration of 228Ra exceeded the World Health Organization (WHO) guideline level of 0.1 Bq/L. The elevated levels of Ra-228 in groundwater were found to be of natural origin, emanating from the aquifer rocks in the study area. Groundwater resources near mining zones showed higher radioactivity levels. The corresponding committed effective dose from consuming such groundwater was estimated to be higher than the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended value of 0.3 mSv/y for children and infants, indicating potential health risks. [ABSTRACT FROM AUTHOR]

Microbial communities are known to contribute deeply to geochemical cycles, including weathering, protection from erosion and mineral precipitation. Studies aiming to understand mining areas' microbiomes are of high relevance since they can help pinpoint the occurrence of environmental shifts, key bioremediation species, environmental metals recovery strategies, and microorganisms with relevant industrial properties. Nonetheless, so far, the study of Portuguese gold-rich areas' microbiomes has been largely neglected. The main goal of this study was to apply high-throughput sequencing methods to study the microbiome (Bacteria and Fungi) and predict their functional/metabolic profiles in an abandoned Portuguese gold mining area (considering zones without a history of mining, the tailings and the flooded mine interior). The results obtained revealed high bacterial and fungal diversities at these sites while also pinpointing the presence of relative homogenous bacterial and heterogenous fungal communities. Areas without mining history were mainly dominated by WD2101 soil groups, Sphingomonas, Candidatus Solibacter, Helotiales, unclassified Fungi and Arxotrichum. The tailings were mainly colonized by Bryobacter, WD2101 soil groups, WPS-2 genera, Starmerella, Helotiales and Mollisia. On the other hand, the mine area displayed a dominance of Crossiella, Gemmataceae, Acidobacteriaceae (Subgroup 1), Acidiphilium, Mortierella, unclassified Fungi and Chaetothyriales. Furthermore, we verified that contrary to bacteria, the fungal structural diversity is somewhat more restricted to each site. In addition, metabolic, functional and ecological profiles revealed a strong distinction for both bacterial and fungal communities while also revealing the presence of well-adapted communities to each of the particular microenvironments considered. [ABSTRACT FROM AUTHOR]

This article explores how the gold mining sector has adapted and evolved in developing countries since the onset of the global pandemic. A major criticism of capital-intensive gold mines has been that they occur as enclaves which fail to catalyze local economic development. Pre-pandemic, the pressure applied by NGOs and donors on gold mining companies to 'de-enclave' was steadily building. It has since dissipated, however, because many governments have declared mining an 'essential' industry. This decision has further entrenched the sector's enclavity by justifying companies' moves to continue operating in isolation and abandon their traditional Corporate Social Responsibility strategies. [ABSTRACT FROM AUTHOR]

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The present study focuses on the assessment of Hg distribution in both soil and water samples from the small-scale gold mining region of Karang Jaya Sub-district, Musi Rawas Utara Regency, South Sumatra Province. For over 30 years, this region has witnessed persistent utilization of mercury as an amalgam for gold extraction. The investigation encompasses an analysis of total mercury levels in soil samples obtained from Sukamenang, Muara Batang Empu, and Terusan Villages. As a comparative reference point devoid of gold mining activities, the neighboring Muara Lakitan Village was selected. The obtained results indicate a moderate to strong contamination level across the 30 sampled locations based on the Geoaccumulation Index (Igeo), with an average Igeo value of 2.6. Furthermore, Pollution Load Index (PLI) and Contamination Factor (CF) values demonstrate high contamination. Conversely, analysis of river water samples from 30 stations along the Rupit River reveals that most of the samples comply with quality standards (<0.0005 mg/L), with an average value at 0.000322 mg/L; only four stations exhibit total Hg concentrations surpassing regulatory thresholds. All soil and river water samples from the control area (10 stations) exhibited no signs of pollution. Appropriate investments in technology, finance, and technical skills are needed to reduce mercury pollution due to small-scale gold mining activities. [ABSTRACT FROM AUTHOR]

Mercury (Hg) is a hazardous pollutant produced during the amalgamation of gold extractiom The environmental problems related to improper Hg waste management have become progressively concerning. Hg contamination in environments can be removed by using bioremediation technology. Utilizing Hg-resistant (HgR) microorganisms in Hg bioremediation is a crucial strategy. Azotobacter is one of the potential microbes for Hg bioremediation bioagent due to exopolysaccharides synthesis that binds the heavy metal. The study's main objective was to select and profile a novel Hg-resistant Azotobacter isolated from heavily Hg-contaminated soil and tailing of artisanal and small-scale gold in Pongkor area, West Java, Indonesia. The completely randomized design was used for profiling Azotobacter-HgR and included Hg values of 0,1,10,100,200, and 400 mg/L. Further, Azotobacter isolate bioassay steps included soil contaminated with Hg, soil contaminated with Hg + Azotobacter sp. S6.a, soil contaminated with Hg + consortium. The profiling results revealed that four Hg-resistant isolates were Azotobacter sp. S5, Azotobacter sp. S6, Azotobacter sp. S6.a, and Azotobacter sp. S9. More importantly, Azotobacter sp. S5 followed by Azotobacter sp. S6.a was found to be the most resistant to Hg exposure at a concentration of 400 mg/L. The Azotobacter sp. S9. produced the lowest EPS, but had the highest activity of nitrogenase and organic acid production. Meanwhile, Azotobacter sp. S6.a. produced the highest EPS. Isolate S5 showed the highest potential as a resistant PGPR-Hg isolate for enhancing the growth of sorghum in Hg-contaminated soil. Sorghum plants accumulate Hg from the soil in the roots but not in the shoots. Present findings suggest that these two isolates have the potential to be used as biological agents to rehabilitate Hg-contaminated soil in Pongkor area. [ABSTRACT FROM AUTHOR]

In the future, phytomining will be an environmentally friendly alternative mining technology. Therefore, the exploration of vegetation types having the potential as hyperaccumulators in gold phytomining needs to be carried out. This study aimed to (1) investigate the effect of rock/soil mineralogy characteristics and Au content on the diversity of vegetation types at gold mine sites, and (2) determine the type of potential hyperaccumulator vegetation as a phytomining agent based on the Biological Concentration Factor (BCF). This study was conducted at the Ratatotok gold mine in North Sulawesi Province, Indonesia. The sampling locations consisted of 3 sites, i.e., Bulex, Yance, and Leon, and each site consisted of 5 sampling plots. Soil samples were taken from each sampling plot and then tested for gold content using the ICP-MS method and mineral content using the XRD method. Mineralized bedrock samples were also taken for mineralogical analysis through petrography. Data analysis of soil geochemistry was carried out descriptively. Quantitative descriptive analysis was also carried out to determine the dominant type of vegetation, which was potential for hyperaccumulators at the mine site. The results showed that gold content in the soil affected the diversity of vegetation, which was possibly due to gold stress, which affected plant growth. Based on the BCF value, three local plant species having potential as gold hyperaccumulators with moderate bioaccumulation ability (BCF>0.1-1) were found, namely Pteris vittata, Syzygium aromaticum, and Swietenia mahagoni. However, the use of these plants as phytomining agents requires further research. [ABSTRACT FROM AUTHOR]

The use of local bacteria is preferred in bioleaching as an environmental-friendly alternative technology in gold mining. In a preliminary study, rhizobacteria were isolated and cultured from three types of hyperaccumulator vegetation from the Ratatotok gold mine, Indonesia, namely Pteris vittata L., Syzygium aromaticum L., and Swietenia mahagoni Jacq. These rhizobacteria still need to be characterised and identified. This study is aimed to cover bacterial phenotypic characterisation, assessment of bacteria resistance to tailing, and identification of bacterial strains the exhibit the highest resistance to tailings. The assessment was carried out across a spectrum of tailing concentrations, selecting the three most robust strains for molecular identification. The process involved genotypic characterisation to determine the species name by analysing the 16S rRNA gene. The results reveal that the phenotypic characteristics of the bacteria isolates vary, but all of them are the indole acetic acid (IAA) hormone producers. The highest IAA producer is the isolate from the rhizosphere of S. aromaticum. Based on the genotypic characterisation test, three most resistant isolates to tailing stress are the following strains Pseudomonas aeruginosa (RTKP1) and Stenotrophomonas geniculata (RTKP2), both from the rhizosphere of P. vittata; as well as Bacillus cereus (RTKS) from the rhizosphere of S. aromaticum. These three strains need to be further tested for their bioleaching capability to recover gold from tailings. Additionally, this study recommends that gold recovery using biological agents can combine the role of hyperaccumulator plants in phytomining and rhizobacteria in bioleaching. [ABSTRACT FROM AUTHOR]

Understanding geological structures is important in mineral exploration. Delineating subsurface geological structures, structural intersections, and complexities of potential geological settings for the formation of hydrothermal mineral deposits, such as gold requires using magnetic data, particularly, high-resolution aeromagnetic data. To define possible targets for mineral exploration, this study used linear detection and the Centre for Exploration Targeting (CET) techniques on high-resolution aeromagnetic data for structural delineation and interpretation. The study's conclusions indicate that the majority of geological features, such as faults, shears, fault intersections, and fracture systems, trend NE-SW, N-S, and occasionally NW-SE. These structures create potentially large areas that have a strong chance of becoming mineralized. The CET grid analysis technique defined mineralized zones, particularly the structural intersections which are potential targets in mineral exploration. The effectiveness of the CET technique in mineral prospecting was demonstrated by the correlation between the results and existing mineral occurrences (such as Shanta Gold Mine, abandoned pits, and the operating pits of smallscale miners in Muhintiri). Based on the findings reported herein, any sites that share characteristics with those that have demonstrated gold mineralization should be prioritized for ground follow-up. [ABSTRACT FROM AUTHOR]

The Kankanaey and Ibaloy Peoples of Itogon, Philippines have been engaged in a long-standing battle against the destructive gold mining operations of the Benguet Corporation. These mining activities have caused significant harm to the environment and have displaced Indigenous Peoples from their ancestral land. The Indigenous communities have formed alliances and protested against the mining operations, leading to a temporary suspension in 1998. However, they continue to fight for their rights and demand compensation, land restitution, and rehabilitation of the region. The Benguet Corporation has been found guilty of violating international human rights law. The text highlights the environmental and social consequences of the mining activities, including sinkholes, landslides, and river pollution. Although the closure of mines in 2017 was a step towards addressing the environmental violations, local communities still rely on small-scale farming for their livelihoods. The text emphasizes the importance of accountability, the return of land to Indigenous Peoples, and the recognition of their ancestral land rights. [Extracted from the article]

The article shares the commercial career of Abraham Salaman, an English Jewish merchant from London, England who migrated to California during the gold rush. It highlights the experiences of Salaman in trading goods and mining gold in mountains in Monterey, California, his business success in Grass Valley as gold mining operations became highly capitalized quartz mills, the failure of his ostrich-feather business and eventual return to London. Also noted is the absence of Jewishness in Salaman.

Gold mining at ore and alluvial deposits substantially negatively impacts the natural environment, in particular, by land degradation and the contamination of watercourses with suspended solids. In this study, we consider a methodology for identifying and mapping the negative impact of gold mining enterprises on the natural environment based on a long-term series of free-available Landsat and Sentinel-2 satellite images. This study is carried out using the example of Tenkinsky, Susumansky, and Yagodninsky districts in Magadan oblast, where the largest gold deposits are located. Identifying features of active mining areas, as well as abandoned ones (on which vegetation began to recover), have been found in satellite images. Based on the expert interpretation of the images and NDVI analysis, it is found that about 2% of the study area has been affected by gold mining. The processes of vegetation recovery are identified only on 10% of the degraded lands. In the Tenkinsky district, the area of disturbed lands for the period 2001–2021 increased more than seven times, which is associated with a substantial increase in gold mining. Using the C2RCC processor (module of the SNAP software package), the content of suspended solids in the water of the most impacted rivers, the Berelekh, Ayan-Yuryakh, and Kolyma, has been estimated in comparison with natural values (typical for noncontaminated water). We have found that the main source of suspended matter in the rivers is the alluvial gold deposits located in the floodplain of the Berelekh River. At the same time, the seasonal variability of water contamination is determined by the hydrological situation. In particular, water turbidity decreases during low water periods and increases during high-flow periods. [ABSTRACT FROM AUTHOR]

Monitoring of bisphenol A (BPHA) is required as its release with byproducts into the aquatic environment every year, causes pollution and toxicity which affects the human health. An efficient electrochemical sensor is therefore needed to determine BPHA in water from natural resources. To construct the sensor, a thin layer of carbon nanotubes (CNTs) is applied to the surface of glassy carbon (GC) then β‐CD and Aunano are sequentially electrodeposited. The performance of the sensor is optimized and shows excellent catalytic effect in wide concentration range 7 nM to 700 μM with low detection limit of 5.02 nM compared to other cited modified electrodes. Each of the sensor constituents share in the enhancement of its performance; Aunano has intrinsic surface electroactivity, β‐CD "host" allows for BPHA "guest" surface accumulation, and CNTs with large conductive surface area realize homogeneous distribution of the other two components. The advantages of the BPHA electrochemical sensor are simple to prepare, timesaving, and shows good sensitivity, stability, selectivity in presence of interfering ions and compounds, it is suitable for use with portable simple equipment for in situ measurements. Furthermore, the application of the sensor in wastewater samples shows good recovery of BPHA. [ABSTRACT FROM AUTHOR]

Background: The contribution of the processes involved and waste generated during gold mining to the increment of heavy metals concentration in the environment has been well established. While certain heavy metals are required for the normal functioning of an organism, certain heavy metals have been identified for their deleterious effects on the ecosystem and non-physiological roles in organisms. Hence, efforts aimed at reducing their concentration level are crucial. To this end, soil and water samples were collected from Ilesha gold mining, Osun State, Nigeria, and they were subjected to various analyses aimed at evaluating their various physicochemical parameters, heavy metal concentration, heavy metal-resistant bacteria isolation, and other analyses which culminated in the molecular characterization of heavy metal-resistant bacteria. Results: Notably, the results obtained from this study revealed that the concentration of heavy metal in the water samples around the mining site was in the order Co > Zn > Cd > Pb > Hg while that of the soil samples was in the order Co > Cd > Pb > Hg > Zn. A minimum inhibitory concentration test performed on the bacteria isolates from the samples revealed some of the isolates could resist as high as 800 ppm of Co, Cd, and Zn, 400 ppm, and 100 ppm of Pb and Hg respectively. Molecular characterization of the isolates revealed them as Priestia aryabhattai and Enterobacter cloacae. Conclusion: Further analysis revealed the presence of heavy metal-resistant genes (HMRGs) including merA, cnrA, and pocC in the isolated Enterobacter cloacae. Ultimately, the bacteria identified in this study are good candidates for bioremediation and merit further investigation in efforts to bioremediate heavy metals in gold mining sites. [ABSTRACT FROM AUTHOR]

Challenges exist in monitoring artisanal and small-scale mining (ASM) activities, given their dynamic and often informal nature. ASM takes form through various techniques and scales, including riverine dredging, which often targets the abundant alluvial gold deposits in South America. Remote sensing offers a solution to improve data collection, regulation, and monitoring of the more mobile and elusive ASM activities and their impacts. Mapping ASM riverine dredges using Synthetic Aperture Radar (SAR) is one of the application areas least explored. Three semi-automated detection approaches using Sentinel-1 SAR are compared on their ability to identify dredges with minimal false positives. The methods are: (i) Search for Unidentified Maritime Objects (SUMO), an established method for large ocean ship detection; and two techniques specifically developed for riverine environments that are introduced in this paper: (ii) a local detection method; and (iii) a global threshold method. A visual interpretation of SAR data with the inclusion of optical high-resolution data are used to generate a validation dataset. Results show it is possible to semi-automatically detect riverine dredge using SAR and that a local detection method provides the best balance between sensitivity and precision and has the lowest risk of error. Future improvements may consider further automation, more discriminatory variables, and analyzing the methods in different environments and at higher spatial resolutions. [ABSTRACT FROM AUTHOR]

Background: Artisanal and small-scale gold mining (ASGM) areas potentially pose increased exposure to arsenic and mercury through community contamination, occupations at gold mines, and/or geophagy when soil is locally sourced. This study examined the effects of geophagy, a deliberate soil eating practice, along with community and occupational exposures in ASGM areas on urinary arsenic and blood mercury levels among pregnant women in the Mining and Health Longitudinal Cohort in northwestern Tanzania. Methods: Data on maternal arsenic and mercury levels were captured for 1056 pregnant women using an unprovoked morning urine samples and dried blood spots respectively. We used a step-wise generalized linear regression model to retain the most relevant covariates for the model. A generalized linear regression model with identity link function was used to predict the effect of geophagy practices on arsenic and mercury levels separately. The model was adjusted using sociodemographic correlates, including maternal age, education level, whether respondents lived in mining or non-mining area, years of residence, marital status, maternal occupation, individual partner's education, and occupational, and socioeconomic status. Results: In the adjusted regression model, eating soil during pregnancy increased arsenic concentration by almost 23% (β = 1.229, 95% CI: 1.094, 1.38, p < 0.001) and living in mining areas had a 21.2% (β = 1.212; 95% CI: 1.039,1.414, p = 0.014) increased risk. Geophagy significantly increased mercury levels by 13.3% (β = 1.133, 95% CI: 1.022, 1.257, p = 0.018). Living in areas with ASGM activities was associated with a 142% (β = 2.422, 95% CI: 2.111, 2.776, p < 0.0001) increase in blood mercury. Conclusion: Geophagy practices increased urinary arsenic and blood mercury levels in pregnant women, which was especially true for arsenic when living in areas with ASGM activities. Working in mining = increased risk for blood mercury levels. Community-based environmental health policies should address reductions in occupational and community exposures, along with strategic geophagy reduction interventions. [ABSTRACT FROM AUTHOR]

In this study, twenty-five yeast strains were isolated from soil samples collected in the gold mining ore in Gia Lai, Vietnam. Among them, one isolate named GL1T could highly tolerate Cu2+ up to 10 mM, and the isolates could also grow in a wide range of pH (3–7), and temperature (10–40 °C). Dried biomass of GL1 was able to remove Cu2+ effectively up to 90.49% with a maximal biosorption capacity of 18.1 mg/g at pH 6, temperature 30 °C, and incubation time 60 min. Sequence analysis of rDNA indicated this strain was closely related to Rhodotorula mucilaginosa but with 1.53 and 3.46% nucleotide differences in the D1/D2 domain of the 28S rRNA gene and the ITS1-5.8S rRNA gene-ITS2 region sequence, respectively. Based on phylogenetic tree analysis and the biochemical characteristics, the strain appears to be a novel Rhodotorula species, and the name Rhodotorula aurum sp. nov. is proposed. This study provides us with more information about heavy metal-tolerant yeasts and it may produce a new tool for environmental control and metal recovery operations. [ABSTRACT FROM AUTHOR]

People making a living in rural Antioquia, Colombia, find themselves in a double bind: they require a healthy environment to farm and grow food, but many turn to artisanal and small-scale gold mining (ASGM) to supplement their incomes. The significant environmental harms associated with ASGM – from mercury and other heavy-metal contamination to deforestation and habitat loss – have led to both academic and popular discourse treating ASGM as an environmental problem to be understood and remedied scientifically. Our research in the small town of Andes (Antioquia region in Colombia) investigated how local residents themselves understood "pollution." Drawing on a literature review, archival research, site visits, and interviews with experts and local residents, we show that rural people understood pollution as emergent from complex webs of relationships and longer histories of government neglect. Exploring how people made sense of harm and expressed care builds on research in STS that demonstrates both the potentials and pitfalls for scientific concepts and tools to understand and intervene in compromised environments. [ABSTRACT FROM AUTHOR]

Gold coins and luxury objects together play a prominent role in the presentation of Visigothic culture in museums as well as in discussions of the early medieval economy and political history of the Iberian Peninsula. Despite this, there is little consensus about the processes by which gold was exploited under Visigothic rule. This article assembles the disparate evidence for mining in Atlantic Iberia, where plentiful gold deposits were previously extracted on a large scale under Roman rule in the north-west and along the Tagus River. It discusses the contributions of numismatic and liturgical objects as well as the limited direct evidence for mining. It then integrates this evidence into discussions of rural settlement, arguing ultimately that mining should be seen as part of a diversified economic strategy among rural labourers, likely carried out on a small-scale basis alongside agriculture and other subsistence activities. [ABSTRACT FROM AUTHOR]

Mine closure in the Witwatersrand Goldfields of South Africa has resulted in an acid mine drainage (AMD) legacy that is difficult to manage and costly to address. As a short-term measure, three large high-density sludge (HDS) plants were erected that treat 185 megalitres of AMD per day (ML/day), at great cost to taxpayers. Longer-term solutions are sought, as the salt load to the Vaal River System is unacceptable. Long-term modelling was used to assess whether the untreated and HDS-treated AMD could be used for irrigation and to determine the scale of the potential opportunity. The Goldfields waters are not very acidic, and simulations indicate it should be feasible to utilise even the untreated water for irrigation, especially if growers commit to applying limestone to their fields. HDS treatment lowers the corrosivity and trace element concentrations, and because the water is gypsiferous, double cropping will precipitate more than a third of the salts in solution as gypsum in the soil profile, thereby reducing salt load to the water environment. The potential irrigated area depends on the cropping system; it is about 9000 ha for rotational cropping and 30,000 ha for supplemental maize irrigation. It is prudent to seriously consider irrigation as a potential long-term water management option for the Goldfields AMD. [ABSTRACT FROM AUTHOR]

This study investigated the contribution of artisanal gold mining and processing activities at the Macalder Mine, Kenya to iron (Fe), copper (Cu), lead (Pb), zinc (Zn), and nickel (Ni) levels in the drinking water of the nearby Macalder Stream and River Kuja. A tailings dump of an abandoned gold mine in the area is the source of the residual ore that is being reprocessed by the artisanal miners. The artisanal mining operations are 60 m and 1200 m upstream of the Macalder Stream and River Kuja, respectively. Pb and Ni levels in gold tailings were within previous reported metal concentrations in gold tailings while, Fe, Cu and Zn exceeded the reported concentrations. The mean Fe, Cu, Pb, Zn and Ni concentrations in Macalder Stream as well as mean Fe, Pb, and Ni concentrations surpassed the World Health Organisation (WHO) recommended standard limits values for drinking water, though mean Cu and Zn concentrations in River Kuja were within permissible WHO standards for drinking water. The similarity between the compositions and concentrations of Fe, Cu, Zn, Pb, and Ni in the reprocessed tailings and water from the stream suggests that the artisanal mining activities are a contamination source. The abrupt improvement in water quality in the River Kuja is likely due to dilution by the relatively unpolluted River Kuja water. [ABSTRACT FROM AUTHOR]

Au–Hg–Ag phases have been described from a variety of metallogenic orebodies and the placer deposits derived from them. In many documented placer deposits, the phases typically occur intergrown as 'secondary' rims to primary Au–Ag grains. The origin of these rims has been ascribed to supergene redistribution reactions during deposition or to the effects of amalgamation (i.e. use of mercury) during mining for gold. Difficulties in determining compositions and crystal structures on such a small scale have made full characterisation of these phases problematic. This paper describes a new occurrence of these phases, found by accident during investigation of a historical concentrate of 'osmiridium' containing a number of gold grains from beach sands at Waratah Bay, in southern Victoria, Australia. The phases occur as rims to gold grains and are intergrown on a scale of tens of micrometres or less. Application of electron microprobe analysis (EPMA) and limited electron back-scattered diffraction (EBSD) was required to characterise them. These techniques revealed the presence of the approved mineral weishanite (Au–Hg–Ag) and a phase with compositional range Au2Hg–Au3Hg surrounding primary Au–Ag (electrum) containing trace amounts of Hg. EBSD analysis showed weishanite is hexagonal P 63/ mmc and Au2Hg to be hexagonal P 63/ mcm. Comparison with published data from other localities (Philippines, British Columbia and New Zealand) suggests weishanite has a wide compositional field. Textures shown by these phases are difficult to interpret, as they might form by either supergene processes or by reaction with anthropogenic mercury used during mining. However, in the absence of any historical evidence for the use of mercury for gold mining at Waratah Bay, we consider the formation of the Au–Hg phases is most probably due to supergene alteration of primary Au–Ag alloy containing small amounts of Hg. In addition to revealing some of the reaction sequences in the development of these secondary Au–Hg–Ag rims, this paper illustrates methods by which these phases can be more fully characterised and thereby better correlated with the Au–Hg synthetic system. [ABSTRACT FROM AUTHOR]

This paper uses support vector machine (SVM), back propagation neural network (BPNN), and Multivariate Regression Analysis (MLA) methods to predict the gold in the Dalli deposit situated in the central province of Iran. After analyzing the data, the dataset was prepared. Subsequently, through comprehensive statistical analyses, Au was chosen as the output element for modelling, while Cu, Al, Ca, Fe, Ti, and Zn were considered input parameters. Then, the dataset was divided into two groups: training and testing datasets. For this purpose, 70% of the datasets were randomly entered into the data process, while the remaining data were assigned for the testing stage. The correlation coefficients for SVM, BPNN, and MLA were 94%, 75%, and 68%, respectively. A comparison of these coefficients revealed that all used methods successfully predicted the actual grade of Au. However, the SVM was more reliable and accurate than other methods. Considering the sensitivity of the gold data and the small number in the exploratory database, the results of this research are used to prepare the main layer in the mineral prospectivity mapping (MPM) of gold in 2 and 3D. [ABSTRACT FROM AUTHOR]

This study serves to demonstrate the application of geophysical data interpretation in order to recognize the structural features related to the mineralization. The aforementioned structures generate the evidence layers, which undergo augmentation and enhancement processes. This results in the production of evidence layers that, when integrated with other geo-exploration evidence layers, contribute to the delineation of mineral exploration targets with increased reliability. In this study, the utilization of aeromagnetic and radiometric data is illustrated for the recognition of structural features and host rocks associated with orogenic gold mineral systems. Furthermore, the integration of geophysical data interpretation, specifically the identification of mineralization-related features, with alterations and the geochemical signature of mineralization is demonstrated. This integration facilitates the delimitation of exploration targets with improved dependability. [ABSTRACT FROM AUTHOR]

This article provides a comprehensive and chronological account of the technological advancements in alluvial gold mining. Gold has been a highly prized commodity throughout history and has played a significant role in humanity's economic and cultural progress. The primitive methods of extracting gold from riverbeds were carried out in Ancient Anatolia and Ancient Greece. The earliest references to the extraction of gold from riverbeds can be traced back to the Argonautic expedition and the myth of the "Golden Fleece". In this myth, fine gold particles were believed to be trapped within the skin of the fleece, thus alluding to the early practices of gold recovery from rivers. Since then, gold extraction and processing technologies have evolved. During the Roman Empire period, Emperor Augustus made significant advancements in hydraulic gold mining. He developed the "ground sluicing" method, which used water to wash away the overlying soil and expose the bedrock where gold deposits were located. Subsequently, the revolutionary pumps described by Georgius Bauer (Agricola) gained significant popularity during the Renaissance. Additionally, Spanish colonialists in America enhanced their techniques by observing the efficient methods employed by the indigenous populations. Finally, the "gold rush" era was perhaps the most crucial period in alluvial gold mining and took place in the rivers of America during the 19th–20th centuries. Today, technologies have evolved significantly, and exploring the evolution of primitive methods to the present is considered essential. [ABSTRACT FROM AUTHOR]

The goals of a "restoration" programme are often not clearly defined, which may radically influence the course of the change effected by the "restoration". In this paper, I examine many restoration studies worldwide, the goals and the practice that was followed. Grasses often play an important role in both the succession and restoration processes. In Johannesburg, South Africa, wind-blown dust caused by gold mining was a problem in the early 20th century, so the goal was to stabilise the tailings. This was achieved by establishing vegetation on the dumps or revegetation of the land on which the tailings were deposited. Stabilisation of the Cape Flats was the goal in the late 19th century to allow easy movement along sandy roads in the region and marram grass was introduced from Europe specifically for this purpose. Revegetation with a different vegetation type is often a logical option where land use is of paramount importance. Replacement with crop plants or grasses is where the previous vegetation is replaced by an alternative land use that will be of benefit to the local people. The terms "rehabilitation" and "restoration" are often used interchangeably. Early researchers on the subject pointed out that rehabilitation is on the trajectory to full restoration or the original former state of the degraded site. In this review, the rehabilitation processes are discussed following dune mining in South Africa and at sites in Mozambique. [ABSTRACT FROM AUTHOR]

The concentration and bioaccessibility of potentially toxic metals, including As, Cd, Cr, Cu, Mn, Ni, Pb and Zn, were determined in surface soil samples from a mining community (Kenyasi) and a non-mining community (Sunyani) in Ghana, to investigate the contribution of mining activities to the environmental burden of potentially toxic metals. The study found significant differences in metal concentrations (p < 0.05) in As, Cd, Cu, Mn, Ni, and Zn, but no significant difference (p > 0.05) in Pb and Cr between the two communities. The study found a moderate correlation between pH and metal concentrations in the mining community and a moderate positive correlation with As, Cd, Cr, Cu, Ni, and Zn in the non-mining community. The distribution pattern revealed elevated levels of toxic metals in the southeastern corridor of the mining community, which is close to a gold mine. Most heavy metals were concentrated in the commercial community's southern zone, with more residents and private elementary schools. Metal bioaccessibility was variable, and except for Cu and Zn, the mean bioaccessibility was less than 50% for a given metal. Contamination factor, geoaccumulation index, and soil enrichment factor suggested very high contamination of Cd, and a considerable to moderate contamination of As, Ni, Zn, and Cu at both the mining and non-mining communities. The above observations and the pollution and risk indices employed in this study confirmed that the mining community was more polluted (PLI = 2.145) than the non-mining community (PLI = 1.372). The total metal hazard (HI) exceeded thresholds by three and four times at non-mining and mining sites. Regular monitoring is necessary, especially in the mining community, to prevent soil metal accumulation. [ABSTRACT FROM AUTHOR]

AbstractIn this study, twenty-five yeast strains were isolated from soil samples collected in the gold mining ore in Gia Lai, Vietnam. Among them, one isolate named GL1T could highly tolerate Cu2+ up to 10 mM, and the isolates could also grow in a wide range of pH (3–7), and temperature (10–40 °C). Dried biomass of GL1 was able to remove Cu2+ effectively up to 90.49% with a maximal biosorption capacity of 18.1 mg/g at pH 6, temperature 30 °C, and incubation time 60 min. Sequence analysis of rDNA indicated this strain was closely related to Rhodotorula mucilaginosa but with 1.53 and 3.46% nucleotide differences in the D1/D2 domain of the 28S rRNA gene and the ITS1-5.8S rRNA gene-ITS2 region sequence, respectively. Based on phylogenetic tree analysis and the biochemical characteristics, the strain appears to be a novel Rhodotorula species, and the name Rhodotorula aurum sp. nov. is proposed. This study provides us with more information about heavy metal-tolerant yeasts and it may produce a new tool for environmental control and metal recovery operations.

This article provides a comprehensive and chronological account of the technological advancements in alluvial gold mining. Gold has been a highly prized commodity throughout history and has played a significant role in humanity’s economic and cultural progress. The primitive methods of extracting gold from riverbeds were carried out in Ancient Anatolia and Ancient Greece. The earliest references to the extraction of gold from riverbeds can be traced back to the Argonautic expedition and the myth of the “Golden Fleece”. In this myth, fine gold particles were believed to be trapped within the skin of the fleece, thus alluding to the early practices of gold recovery from rivers. Since then, gold extraction and processing technologies have evolved. During the Roman Empire period, Emperor Augustus made significant advancements in hydraulic gold mining. He developed the “ground sluicing” method, which used water to wash away the overlying soil and expose the bedrock where gold deposits were located. Subsequently, the revolutionary pumps described by Georgius Bauer (Agricola) gained significant popularity during the Renaissance. Additionally, Spanish colonialists in America enhanced their techniques by observing the efficient methods employed by the indigenous populations. Finally, the “gold rush” era was perhaps the most crucial period in alluvial gold mining and took place in the rivers of America during the 19th–20th centuries. Today, technologies have evolved significantly, and exploring the evolution of primitive methods to the present is considered essential.

This study aimed to investigate the effect of gold mining on soil properties. Soil samples were taken from the post-gold mining land, the property of PT Panca Logam Nusantara and PT Alam Buana Indonesia, and a nearby natural forest in Bombana, Southeast Sulawesi Province. The next step focused on specifying soil pH, total nitrogen (TN) and carbon (TC) concentration, C/N ratio, available phosphorus (P) concentration, cation exchange capacity (CEC), and exchangeable K, Na, Mg, Ca, Fe, Mn, Cd and Pb concentration, texture and spore amount, AMF resource and AMF colonization. The result shows that the pH in post-gold mining soil was higher than that in natural forest soil. Meanwhile, TN, TC, available P, and CEC of post-gold mining soil got lower compared with these of natural forest soil. The texture in the post-mining soil was clay loam, while that in natural forest soil was clay. Total of 10 AMF species belonging to five genera and three families were found in a post-gold mining area. Soil pH, CEC, soil texture, Mn, and total Fe had a negative relation with AMF colonization and spore count, while organic C, total N, C/N ratio, P2O5 and silt had a positive relation. Sand was proven to have a strong and positive correlation with the amount of AMF species. Adding organic matter and fertilization as well as applying mycorrhizal biofertilizers, were urgently required to support the effort in restoring post-gold mining soil.