Small-scale Gold Mining Activities Research Articles

Interpretation of surface structure on artisanal and small scale gold mining areas with geoelectric resistivity method of schlumberger configuration in Sekotong, West Lombok

West Nusa Tenggara (NTB) has a very diverse mineral content both metal and non-metal minerals. Sekotong Sub District in West Lombok Regency has mineral resources such as gold, copper, and silver. Artisanal and small scale gold mining activities are carried out without calculating how much potential mining materials are available and at what point and at what depth the minerals are located, the required cost, labor and time. Similarly, cases that occur in artisanal and small scale gold mining areas also occur in the Rambut Petung area, Sekotong Sub District. Therefore, special methods are required to determine the presence of excavated materials that settle beneath the surface of the earth. The method that is often used in identifying subsurface is the geophysical method. The utilization of geophysical methods must be under the nature of the materials to be examined. The data processing results indicate that there are layers consisting of breccias, lava, tuff with lens limestone. Based on the resistivity log, the resistivity value is 44.56 ohms, 3-11 m the resistivity value is 17.33 ohms, 11-89 the resistivity value is 42.39 ohms, and the value of 89-130 is 309.81 ohms.

Chronic Effect Analysis of Mercury Exposure on Communities Around Small Scale Gold Mining in Indonesia Using Human Biomonitoring (HBM) Method

In general, small-scale gold mining activities that are spread throughout Indonesia practicing amalgamation technique. The amalgamation process in the mining activities can result in environmental degradation due to tailing waste containing mercury that are discharged into the environment and will distributed and bioaccumulated through food chain. Mercury exposure to human can give a chronic effect. Measuring mercury concentration in biomarkers such as nail and hair is a method to indicate the mercury poisoning level. Therefore, the purpose of this study was to analyze mercury concentrations in nail and hair as chronic exposure biomarkers. Besides, we also conducted Human Biomonitoring (HBM) analysis to assess mercury intoxication in the communities. Moreover, we analyzed mercury concentrations in water, rice, fish, and food crops samples to understand their association with mercury concentrations in nail and hair through a Provisional Tolerable Weekly Intake (PTWI) analysis. This research was conducted in 4 districts in Indonesia which has a significant number of small-scale gold mining activities. The results showed that the maximum concentration of T-Hg in the nail and hair of the workers was 58.48 µg/g and 55.97 µg/g, respectively. Based on HBM analysis, in several districts, more than 60% of the workers has been intoxicated by mercury. Meanwhile, Average Daily Intake (ADI) and PTWI were significantly correlated with concentration mercury in the nail and hair. Mercury concentrations in worker’s hair was significantly correlated with working experience. We identified that the age and residence duration were the major predictor of concentration mercury in nail and hair, respectively.

Time variation in transfer amounts of mercury by a river system near an artisanal and small-scale gold mining area in West Java, Indonesia

To evaluate the impact of mercury released into a river system by artisanal and small-scale gold mining (ASGM) activity in West Java, Indonesia, the temporal variations in elemental mercury, mercury ions, dissolved total mercury and particulate mercury concentrations in river water were observed in March 2015 (rainy season) and August 2015 (dry season) at a fixed observation point, and the migrated amount of mercury was estimated. Variations for other metals, total organic carbon (TOC), and total nitrogen (TN) contents were also measured. There have been few reports in which the amount of mercury transferred from ASGM activities is quantitatively estimated, and this study provides important data for evaluating the environmental impact of mercury released by ASGM activities. The concentration of filtered total mercury and the particulate mercury concentration observed in the dry season were 161 ± 167 μg L−1 and 142 ± 93 μg L−1, respectively, and these values were significantly higher than the values of 24.5 ± 23.9 μg L−1 and 53.7 ± 44 μg L−1 for filtered total mercury and particulate mercury, respectively, observed in the rainy season. On the other hand, the river flow in the rainy and dry seasons was 2.6 × 104 ± 5×103 m3 h−1 and 8.2 × 103 ± 8×102 m3 h−1, respectively, and an apparent increase in the amount of water in the rainy season was observed. The transfer amounts in the rainy and dry seasons obtained from these results were 6.2 × 102 ± 6.7 × 102 g h−1 and 1.6 × 103 ± 1.6 × 103 g h−1, respectively, for filtered total mercury and 1.3 × 103 ± 1.3 × 103 g h−1 and 1.1 × 103 ± 7×102 g h−1, respectively, for particulate mercury. The temporal variations in these values exhibited a wide range, indicating the effects of weather conditions and of the mining process.

Neuropathological lesions in the brains of goats in North-Western Nigeria: possible impact of artisanal mining.

Indiscriminate small-scale artisanal gold mining activities were reported to have caused anthropogenic heavy metal environmental pollution in Zamfara State, north-western Nigeria. There is little or no information on the neurotoxic effects and related neuropathological lesions due to environmental pollution in the animal population. Therefore, this work investigated the concentration of heavy metal and associated lesions in the brain of goats around an artisanal mining site in Zamfara. Brain samples were collected from 40 goats at slaughter slabs in Bagega (Zamfara State) while 15 goats with the same demography but without a history of environmental exposure at the time of this study served as controls. The concentration of lead and cadmium in brain tissue and histopathologic changes were assessed using atomic absorption spectrophotometry, histology and immunohistochemistry. The metal concentrations were significantly higher in exposed goats than in the unexposed animals. Cresyl violet staining and glial fibrillary acidic protein (GFAP) immunohistochemistry indicated chromatolysis and increased astrocytic activity respectively in the exposed goats. This study is of epidemiological importance as it shows a generalised increase of the metal concentrations in the brain of goats exposed to artisanal mining in Zamfara, north-western Nigeria. This could have health effects on the animals associated with nervous co-ordination, growth and development and as a good sentinel for pathogenesis of the heavy metal exposure.

Mercury exposure assessment in indigenous communities from Tarapaca village, Cotuhe and Putumayo Rivers, Colombian Amazon.

Mercury (Hg) is a complex and multifaceted global pollutant. Artisanal and small-scale gold mining activities are largely responsible for Hg contamination in developing countries, in many cases impacting areas of high biodiversity such as the Amazon. The aim of the study was to establish Hg exposure in indigenous citizens from the Tarapaca village, Cotuhe and Putumayo Rivers, at the Colombian Amazon. Total Hg (T-Hg) concentrations were measured employing a DMA-80 Hg analyzer. For that purpose, 190 hair samples were taken from volunteers living in different communities of Tarapaca. The overall mean T-Hg level for all samples was 10.6 ± 0.4 μg/g, with values ranging from 0.61 to 31.1 μg/g. The mean T-Hg level decreased in the order Puerto Huila > Puerto Ticuna > Ventura > Nueva Union > Buenos Aires > Santa Lucia > Puerto Nuevo > Caña Brava > Pupuña. Based on recommendations from the United States Environmental Protection Agency (US EPA), 99.5% of the samples exceeded the maximum level of 1.0 μg/g. Hg content in human hair was significantly associated with fish consumption (ρ = 0.253; p < 0.001). According to the health survey, at least 24.7% of the volunteers manifested some signs and symptoms of Hg poisoning. In short, these data support the extensive Hg exposure in the environment of the Colombian Amazon, a process that could be impacting the quality of life of its vulnerable indigenous groups. Immediate actions must be taken by competent authorities to protect these communities from Hg poisoning.

Liquid waste pollution model and characterization levels from small-scale gold mining activities

Small scale mining system carried out by local residents in Bunikasih, Sukaluyu Village, Pangalengan District, Bandung Regency causes environmental pollution and long-term ecosystem damage. This is because the mining method does not follow the rules set by the government. To find out the amount of pollution that has occurred, this study was conducted. The research methodology used starts from taking field data samples, then analyzes the chemistry for clean water and waste chemicals. From this study it was found that the presence of heavy metal mercury (Hg) due to mining activities and processing of gold ore using amalgamation with values in the upper reaches of Ciwiwi River = 0.085 mg / kg, in the area of amalgamation gold ore processing = 0.11 mg / kg, and in the lower reaches of Ciwiwi River = 0.097 mg / kg.

Mercury (Hg) contamination on water, sediment and macrozoobenthos in Waelata River, Wamsait Village Waelata Sub-district, Buru District, Maluku Province

Gold was found in Buru Island, Maluku Province, Indonesia in November, 2011. Since then, the artisanal small-scale gold mining (ASGM) activity was started in Botak Mount up to now. Mercury was used to extract gold through amalgamation process and produce high volume of wastewater contaminated by Hg to Waelata River, straight to Kayeli Bay. This caused serious problem for the environment. Sampling was done in three locations in Waelata River, Wamsait Village, Waelata Sub-District, Buru District, with the three times of repetition to determine the mercury (Hg) concentration level in the water, sediment and macrozoobenthos. The research result showed that the highest Hg concentration mean in the water, sediment and macrozoobenthos was in ST.02 with the respective values namely 0.0012±0.0001 ppm, 0.0833±0.0062 ppm and 0.0088±0.0003 ppm. On the other hand, the lowest Hg concentration mean was found in ST.01 with the respective values namely < 0.0005±0.0000 ppm, 0.0228±0.0019 ppm and 0.0050±0.0034 ppm. The wastewater was produced by the gold mining activities that did not flow to ST.01, so that Hg in the wastewater did not have any correlation with the Hg in sediment and macrozoobenthos (p<0.05), however it flowed from ST.02 to ST.03 so that the Hg in the water has correlation with Hg in sediment and macrozoobenthos (p>0.05).

Quantification and characterization of mercury resistant bacteria in sediments contaminated by artisanal small-scale gold mining activities, Kedougou region, Senegal

This study describes Hg-resistant bacterial present in the aquatic sediments artisanal small-scale gold mining ASGM activities along Gambia River Kedougou, Senegal. Mercury (Hg) is used for gold amalgamation in artisanal small-scale gold mining (ASGM) activities. The level of total Hg in sediment samples was determined by automatic mercury analyser. Bacterial (colony-forming units) susceptibility to Hg was evaluated by minimal inhibitory concentrations. The phylogenetic diversity analysis of the Hg-resistant bacteria was performed by PCR amplification of 16S rDNA on isolated bacterial strains, followed by restriction fragment length polymorphism, cloning and sequencing. The results documented high concentrations of Hg in ASGM activity areas ranging from 2.4 to 6.2 mg kg-1. Population densities of heterotrophic bacteria in wet sediment ranging from 3.7 × 106 to 4.6 × 108 CFU g−1. The isolated bacterial strains from highly Hg-contaminated sites can grow to medium containing up to 17 mg L−1 of Hg2+. In this study, bacterial strains resistant to Hg are Stenotrophomonas maltophilia, Dyella ginsengisoli, Arthrobacter defluvi, Arthrobacter pascens, Bacillus firmus and Pseudomonas moraviensis. Our results demonstrate the occurrence the presence of diverse groups of bacterial strains resistant to metal (Hg) under tropical conditions. The isolated strains are particularly interesting for further studies to evaluate their role in bioremediation of Hg in contaminated aquatic ecosystems.

Transport of mercury species by river from artisanal and small-scale gold mining in West Java, Indonesia.

To estimate the impact of mercury discharged from artisanal and small-scale gold mining (ASGM) activity, variations in the concentrations of elemental mercury (Hg0), mercury ion (Hg2+), particulate mercury (P-Hg), and total mercury in filtered river water (FT-Hg) were investigated from sampling locations extending from 10km upstream to 30km downstream of ASGM operations in West Java, Indonesia. The average of the annual concentrations at the ASGM site from 2013 to 2017 were 0.14-0.85μgL-1, 0.27-12.9μgL-1, 4.3-49.5μgL-1, and 1.2-12.5μgL-1 for Hg0, Hg2+, P-Hg, and FT-Hg, respectively. The concentration of mercury species decreased as the distance from the ASGM site increased, while the ratio of P-Hg increased towards the lower reaches of the river system, with the percentage of P-Hg estimated at 90% of Hg at the sample location furthest downstream. A high mercury concentration of 600mgkg-1 was observed for suspended particulate matter (SPM) at the ASGM site. The SPM maintained a high concentration of mercury, even in the downstream area. In the annual variations of the mercury species from 2013 to 2017, FT-Hg and P-Hg concentrations tended to decrease from 2016, which suggested a decline of ASGM activity in this area. However, SPM and river sediment showed no apparent changes in their mercury concentrations over this period, indicating that the contamination in the river system is persistent and does not recover quickly.

Validation of Dried Blood Spots for Maternal Biomonitoring of Nonessential Elements in an Artisanal and Small-Scale Gold Mining Area of Tanzania.

Biomonitoring studies of vulnerable populations in low- and middle-income countries are limited because traditional sampling methods are challenging to implement in low-resource settings. The present study examined the feasibility, precision, and accuracy of dried blood spots (DBS) for human biomonitoring of nonessential elements (cadmium [Cd], mercury [Hg], and lead [Pb]) in an area of northern Tanzania with artisanal and small-scale gold mining activities. Pregnant women (n = 44) were recruited in Geita during antenatal clinic visits, and DBS from capillary blood were collected on filter paper. As a gold-standard comparison, venous blood was sampled from the same participants and compared with the DBS. Venous blood, DBS, and quality control samples were analyzed for chemical elements by inductively coupled plasma mass spectrometry. Field blanks were very clean for most elements, generally only twice as high as corresponding laboratory filter blanks. No significant differences were found between duplicate DBS samples taken from the same participants, with near perfect intraclass correlation coefficients (0.99) for Cd, Hg, and Pb, indicating excellent reliability. Moreover, correlation was strong (r2 > 0.9) and significant (p < 0.0001) between DBS and the quantitative venous blood, with regression line slopes close to 1.0 (0.847, 0.976, and 0.969 for Cd, Hg, and Pb, respectively), indicating high accuracy of the DBS method compared with the gold-standard approach. The DBS method is minimally invasive and was a feasible, precise, and accurate means of measuring exposure to Cd, Hg, and Pb in pregnant women in a low-resource setting. Environ Toxicol Chem 2019;38:1285-1293. © 2019 SETAC.

Over-spilling institutions: The political ecology of ‘greening’ the small-scale gold mining sector in Guyana

This article applies a political ecology framework to examine the challenges of ‘greening’ Guyana’s relatively established small-scale gold mining sector. Based on a year of fieldwork conducted in Guyana’s gold mining landscape, the article highlights a range of ways in which the supposed stability and transparency of Guyana’s institutional mining framework is undermined by the dynamic and discretionary realities of actual small-scale gold mining activity. The tendency of mining activity to overspill institutional boundaries is contributing to worsening ecological conditions in the country’s interior. For miners, it is shown that, even having acquired or accessed formal property, they face various challenges (such as minimal state support, stressed conditions of production, and tenure insecurity) that compromise their ability to enact ‘green’ mining. The state meanwhile faces related challenges in ensuring that dynamic and fluid mining activity remains within its legal and literal boundaries. Overall, the article illustrates how the mainstream green mining ‘storyline’ – based on the notion of formal institutions as a disciplining or containing force – is disrupted by an intimate interaction among unruly socio-ecological realities.

Risk of Mercury Exposure from Fish Consumption at Artisanal Small-Scale Gold Mining Areas in West Nusa Tenggara, Indonesia.

Background.The primary environmental risk associated with artisanal small-scale gold mining (ASGM) activities in Sekotong and Taliwang is waste discharged directly into the environment. This waste contains variable concentrations of heavy metals and a high level of mercury. When these elements are released into the environment, plants and animals can be contaminated. If mercury is methylated to methylmercury, levels can increase in concentration at each level of the food chain (biomagnify). Fish are a primary risk vector for methylmercury poisoning in humans, and represent a significant source of protein for the Sekotong and Taliwang communities.Objectives.The present study aimed to identify the concentration of mercury in fish from ASGM sites in Sekotong and Taliwang.Methods.Descriptive research was used to describe the mercury concentrations of fish in the present study. The fish species collected for the samples represented commercially available fish most commonly consumed by the community on a daily basis.Results.In Sekotong's ASGM area, the mercury concentration in Pilsbryoconcha exilis tissue was 596 ppb, 721 ppb for Sephia officinalis and 50% of the Euthynnus affinis samples had a high level of mercury, above the World Health Organization (WHO) maximum permissable limit for the sale of fish for human consumption of 0.5 ppb.Conclusions.Some fish species from the studied ASGM sites had high mercury concentrations above the maximum permissible mercury concentration in edible fish tissue. The risks associated with mercury exposure from fish consumption threaten community health.Ethics Approval.All experiments were performed in accordance with relevant local guidelines and regulations.Competing Interests.The authors declare no competing financial interests.

An assessment of the impact of artisanal and commercial gold mining on mercury and methylmercury levels in the environment and fish in Cote d'Ivoire

Artisanal and small-scale gold mining (ASGM) activities are an important source of mercury (Hg) to the atmosphere globally, and in most countries in West Africa, where gold production has increased dramatically in the last decade from both commercial and ASGM activities. This study focused on examining the concentrations of Hg and methylmercury (MeHg) in water, sediments and fish in four regions associated with gold mining activities in Cote d'Ivoire to assess the potential exposure of the local communities to MeHg from fish consumption. Concentrations of dissolved total Hg and MeHg in water and sediment were elevated at some locations sample and were indicative of local contamination. Several locations had sediment total Hg above 100 ng g−1 and sediment %MeHg ranged from 0.03 to 4.4%. Fish concentrations exceeded 0.3 μg/ g wet wt., especially for carnivores and fish caught in the western region of the country. Bioaccumulation factors, relative to dissolved MeHg, were higher for carnivores than omnivores and varied with region, suggesting other factors besides MeHg concentration alone were impacting uptake and trophic transfer. Given that people in Cote d'Ivoire consume fish at a higher level than other countries, the levels in fish were sufficient to exceed the US EPA's guidance criteria even at average consumption levels, and particularly for people consuming fish at a higher rate. Overall, this study provides compelling evidence that ASGM activities in Cote d'Ivoire are leading to elevated exposure and likely impacting the health of the local populations in regions where such activity is occurring.

Effects of small-scale gold mining on heavy metal levels in groundwater in the Lower Pra Basin of Ghana

The effects of small-scale gold mining activities on heavy metal levels in groundwater were determined for the Lower Pra Basin of Ghana. Sixty five boreholes in 45 communities were analysed between January 2012 and April 2012 for the dry season and June and October 2012 for the wet season. The test for significance and the use of cluster analysis, a multivariate approach, clearly delineate Cu, Zn, Cd and Hg as possible anthropogenic contributors, whilst As, Se and Pb could be both anthropogenic and natural geochemical process contributors of metal level concentrations in the groundwater. The analysis shows generally low pH values in the basin with more than 95% of dry season and almost all wet season values being acidic or slightly acidic. Approximately 35% of boreholes in the wet season recorded values for cadmium above WHO guideline value of 3.0 µg/l with almost all dry season values falling below 3.0 µg/l except for two boreholes. Generally, high values were recorded for iron, manganese, lead, Al and Hg. In general, lead, copper, cadmium and manganese showed higher wet season values than dry season suggesting anthropogenic influence.

Cladophora sp. Biosorption of Metal-contaminated Water

Artisanal and Small-scale Gold Mining (ASGM) activities employing the mercury amal-gamationtechnique have resulted in a significant drop in the quality of water from Ngwabalozi River, Zimbabwe. Mercury levels as high as 0.31 mg L-1have been reported in its waters and the low river pH (pH 3) favors proliferation of microorganisms responsible for methylmercury (a potent neurotoxin) formation. Thus, removal of mercury from contaminated systems is a priority. Therefore, the aim of this study is to develop a low-cost batch reactor for the removal of mercury from mercury contaminated acidic waters tomeet the World Health Organization (WHO) standard of 0.006 mg L-1using Cladophorasp. algae. Optimum reactor parameters were deter-mined by studying the effect of contact time, pH, initial mercury concentration and the presence of competing cations on the adsorption of mercury by Cladophorasp. The mass of algae required in a 1000 Lbatch reactor was then determined at the optimum adsorption conditions for the single and multi-component solution systems. A rapid uptake of mercury by Cladophorasp. algae was displayed. More than 99% of the mercury in solution was removed within the first five minutes of contact and equilibrium was attained after ten minutes. High adsorption capacities (up to 805 mg kg-1at pH 3) were obtained at the optimum mercury concentration of 1.0 mg L-1. Competitive adsorption studies showed that the selectivity of cations by Cladophora sp. was in thefollowing order: Hg2+˃ Fe2+˃ Cu2+˃ Zn2+˃ Co2+. Based on the optimized reactor conditions, nearly 4.8 kg of Cladophorasp. per 1000 Lbatch is required to treat the water in Ngwabalozi River for a mercury only solution. However, for a multi-component system, the mass of Cladophorasp. required was more than triple (17.1 kg) the mass required in a single component solution.

Mercury Levels in Women and Children from Interior Villages in Suriname, South America.

Natural sources of mercury, historical gold mining, and contemporary artisanal and small-scale gold mining (ASGM) activities have led to mercury contamination in Suriname. Our primary objective was to evaluate mercury levels in hair of women and children from interior villages in Suriname where mercury levels in fish are elevated. We also estimated blood levels of mercury using an established mathematical conversion to facilitate comparison with other biomonitoring programs in the United States. Estimated levels of mercury in the blood of participants from Suriname were significantly higher than those in women from a heavy marine fish-consuming population in southeast Louisiana and estimates of the US national average. This includes women from Surinamese villages well upstream of ASGM activities. Since residents in these areas rely heavily on local fish, this is likely the source of their exposure to mercury. The levels in hair are similar to those seen in women from longitudinal studies finding neurological impairments in children exposed pre- and postnatally. Additional biomonitoring and neurodevelopmental assessments are warranted in these areas, as well as other areas of the Suriname. Mercury levels in hair (Suriname) and blood (southeast LA USA) were determined using cold vapor atomic absorption spectroscopy (CVAAS).

Senegalese artisanal gold mining leads to elevated total mercury and methylmercury concentrations in soils, sediments, and rivers

The largest source of global mercury (Hg) anthropogenic inputs to the environment is derived from artisanal and small-scale gold mining (ASGM) activities in developing countries. While our understanding of global Hg emissions from ASGM is growing, there is limited empirical documentation about the levels of total mercury (THg) and methylmercury (MeHg) contamination near ASGM sites. We measured THg and MeHg concentrations in soil (n = 119), sediment (n = 22), and water (n = 25) from four active ASGM villages and one non-ASGM reference village in Senegal, West Africa. Nearly all samples had THg and MeHg concentrations that exceeded the reference village concentrations and USEPA regulatory standards. The highest median THg concentrations were found in huts where mercury-gold amalgams were burned (7.5 μg/g), while the highest median MeHg concentrations and percent Hg as MeHg were found in river sediments (4.2 ng/g, 0.41%). Median river water concentrations of THg and MeHg were also elevated compared to values at the reference site (22 ng THg/L, 0.037 ng MeHg/L in ASGM sites). This study provides direct evidence that Hg from ASGM is entering both the terrestrial and aquatic ecosystems where it is converted in soils, sediment, and water to the neurotoxic and bioavailable form of MeHg.

Analysis of Artisanal Small-scale Gold Mining Sector in West Sumbawa Regency, Indonesia.

Background.The high value of gold reserves in West Sumbawa Regency (WSR) and West Nusa Tenggara Province, Indonesia has resulted in an increase in small-scale gold mining activity in this area. Artisanal and small-scale gold mining (ASGM) is an attractive alternative livelihood for rural workers because it has good potential to improve the wealth of a community. Miners need very little training to mine gold and the transition from traditional farming or fishing is easy to make. However, the key environmental consequence of ASGM in West Sumbawa is the extensive use of mercury and its impact on human health.Objectives.The ASGM activity in WSR is quite recent when compared to other ASGM activity in Indonesia. The current study was conducted to better understand the lifestyle, extent of mercury exposure, and the health of people living in WSR, West Nusa Tenggara Province, Indonesia.Methods.The present study was designed as a purposive field sampling study conducted in WSR, West Nusa Tenggara Province, Indonesia. The subjects were miners and families from three different sites within the WSR: individuals directly exposed to mercury, indirectly exposed individuals and non-exposed individuals. Hair mercury analysis was done with all subjects. Health questionnaires, physical examinations and socio-economic surveys were conducted with exposed subjects.Results.The ASGM sector in the WSR consists of a high number of migrant workers who have a great economic impact on the local area, high mercury use, a great deal of illegal mercury trading, and a high mercury concentration (>13 mg/kg) in their hair. The results suggest that ASGM activities affect the health of exposed and indirectly exposed individuals.Conclusions.The current scale of ASGM activity in the WSR is predicted to rise. ASGM activities in the WSR is an important challenge that needs to be addressed.

An inter-laboratory comparison of different analytical methods for the determination of monomethylmercury in various soil and sediment samples: A platform for method improvement

An inter-laboratory study was conducted to compare results from different analytical methods for monomethylmercury (MeHg) concentrations in 17 soil and sediment samples. The samples were collected from mercury-contaminated areas, including Minamata Bay and Kagoshima Bay in Japan, the Idrija mercury mine in Slovenia, and an artisanal small-scale gold mining area in Indonesia. The Hg in these samples comes from several different sources: industrial waste from an acetaldehyde production facility, volcanic activity, Hg mining activity, and artisanal and small-scale gold mining activity (ASGM). MeHg concentrations in all the samples were measured in four separate laboratories, using three different determination methods: Kagoshima University (Japan), using high-performance liquid chromatography–chemiluminescence detection (HPLC-CL); National Institute for Minamata Disease (Japan), using gas chromatography–electron capture detection; and Metropolitan Council Environmental Services (USA) and Jozef Stefan Institute (Slovenia), both using alkylation-gas chromatography–atomic fluorescence spectrometry detection. The methods gave comparable MeHg results for most of the samples tested, but for some samples, the results exhibited significant variability depending on the method used. The HPLC-CL method performed poorly when applied to samples with elevated sulfur concentrations, producing MeHg concentrations that were much lower than those from the other methods. Additional analytical work demonstrated the elimination of this sulfur interference when the method was modified to bind sulfur prior to the analytical step by using Hg2+ as a masking agent. These results demonstrate the value of laboratory intercomparison exercises in contributing to the improvement of analytical methods.

Acute and Chronic Toxicity of Mercury Exposure in Seafood and Human Populations near a Small-Scale Gold Mining Area

&lt;p&gt;Gold amalgamation processes using mercury were practiced in small scale gold mining activities in Krueng Sabee, Aceh Province. Seafood (fish, mollusc, shrimp) and human hair samples were collected to assess mercury concentrations. Acute and chronic toxicity symptoms which arise among the populations were observed as well as personal protective equipment used by gold miners. The range of mercury concentrations varied among fish, shrimp, and molluscs. The highest mercury levels were recorded in fish &lt;em&gt;Puntius latristriga&lt;/em&gt; (172.299 ± 10.626 µg/g wet wt.), followed by mollusc, &lt;em&gt;Polymesoda caroliniana &lt;/em&gt; (160,032 ± 0,522 µg/g wet wt.), fish &lt;em&gt;R.kanagurta&lt;/em&gt; (149 ±2,000 µg/g wet wt.), shrimp &lt;em&gt;Penaeus monodon&lt;/em&gt; (116.975 ± 4.807 µg/g wet wt.). The variation of mercury concentrations in hair samples of 72 respondents were detected from 5.7 µg/g to 88.1 µg/g. The most frequent acute and chronic intoxication symptoms documented were headache, muscle cramps, cough, and aphthous ulcers. Personal protective equipment which has correlation with high mercury levels in gold miners were respirator/mask, gloves, and apparel (p &amp;lt; 0.05). All seafood samples exceeded 0.5 µg Hg/g MoH Food and Drug Administrasion threshold level and hair samples over 10 µg/g as set by WHO tolerance limit.&lt;/p&gt;