Gold Mining Activities Research Articles

Biomonitoring of Mercury and Lead Levels in the Blood of Children Living near a Tropical River Impacted by Artisanal and Small-Scale Gold Mining in Colombia.

(1) Background: Mercury and lead contamination resulting from various anthropogenic activities represents a global environmental problem and a considerable risk to the health of the human population. (2) Methods: The objective of this research was to evaluate the concentrations of mercury (Hg) and Lead (Pb) in the blood of the child population in the municipalities in the Atrato River basin using a direct Hg analyzer and graphite furnace atomic absorption spectrometry. (3) Results: In total, 171 children (5-14 years of age) were taken into account, and 18.71% (32) of the children had concentrations of Hg and Pb above the permissible values established by the WHO. In the municipality of UN, 19 children had blood Hg concentrations between 5.29 and 17.71 μg/L. In CA, two children had concentrations of 5.03 and 8.43 μg/L, separately. In the case of Pb, seven children showed concentrations between 3.60 and 4.83 μg/dL in the municipality of RQ, three in UN (3.59, 3.61, and 4.60 μg/dL), and one in Carmen de Atrato (5.47 μg/dL). (4) Conclusions: The levels of Hg and Pb in the blood of children living in the riparian areas of the Atrato River basin are related to gold mining activities in the basin and the consumption of contaminated fish.

Penerapan Metode Enhanced Phytoremediation pada Lahan Bekas Tambang Emas Desa Tirta Kencana Kecamatan Bengkayang

Community gold mining activities using the amalgamation method cause soil pollution due to the use of mercury (Hg) to extract gold content which causes a decrease in soil quality and environmental damage. Enhanced phytoremediation is a method that can be applied to remove mercury levels with using the Cyperus kyllingia plant and adding supporting elements in the form of bacterial isolates that are resistant to mercury. This research aimed to determine the effectiveness of Cyperus kyllingia plants and bacterial isolates for removing mercury levels in mercury-contaminated soil, as well as observing the bacterial population and plant morphology during the research. Based on the research results, it is known that the best efficiency value for removing mercury levels is found in phytoremediation with the addition of bacterial isolates, namely 86.88%. The largest bacterial population was found in the phytoremediation reactor with the addition of bacterial isolates, namely 73.3 × 106 CFU/mL. The mercury content in polluted soil causes changes in plant morphology, namely the color of green plants changes to yellow, but plants can reproduce as indicated by an increase in the number of leaves and plant stems

How Does Small-Scale Mining Stabilize Rural Livelihoods in Sub-Saharan Africa? The Case of Mozambique

This paper examines the linkages between subsistence farming and artisanal and small-scale mining (ASM) – low-tech, labor-intensive mineral extraction and processing – in sub-Saharan Africa, focusing on the case of Mozambique. While the body of literature on this subject is burgeoning, it is comprised mostly of conceptual pieces and country case studies that rely heavily on qualitative data. Focusing on Manica Province, long an epicentre of small-scale gold mining activity in Mozambique, the paper showcases the value of including complementary quantitative data in analyses of ASM-farming linkages in rural sub-Saharan Africa. In particular, quantitative data that provide detail on the demographical composition of communities engaged in both ASM and agriculture, and which shed light on the spending patterns of households involved, could go a long way toward enriching dialogues on this subject, and, in the process, yield more effective (and, indeed, representative) rural development and poverty alleviation strategies in the region. The data gathered in Manica Province provide a more nuanced picture of how the ages and educational levels of household heads, and the sizes of their families, shape views on ASM and agriculture in gold-rich sections of Mozambique. Studies exploring the linkages between ASM and agriculture in sub-Saharan Africa that feature both qualitative and quantitative data provide greater clarity on the role each activity could play in tackling some of the region’s broader development challenges, including food insecurity and (building) community resilience.

Community engagement in mobile and hard-to-reach populations: a community-based intervention for malaria elimination in a tri-national region of the Guiana Shield.

Several countries of the Guiana Shield are aiming at the control and elimination of malaria in areas where Artisanal and Small-scale Gold Mining (ASGM) activities predominate, raising questions about how to strengthen community engagement to improve the effectiveness of health programs. The Curema project focuses its intervention on the mobile and hard-to-reach ASGM population, complementing the efforts of national programs in the Guiana Shield. The Curema intervention combines targeted drug administration for suspected Plasmodium vivax asymptomatic carriers, the Malakit distribution, and health education activities. The primary goals of this manuscript are to outline a pathway to foster community participation in the Curema project aimed at eliminating malaria. Thus, it presents a vision of the challenges that the AGSM community poses in terms of community participation for an asymptomatic problem; and highlights the community-based model and the Information, Education and Communication (IEC) components as foundations for participation. In addition, it also presents culturally sensitive IEC strategies designed through iterative and collaborative consultative processes and other bottom-up outreach activities. The community engagement approach facilitates adaptability and responsiveness in a complex, evolving context increasing the effectiveness of interventions.

The impact of gold mining activities: understanding the dynamics of cyanide in river ecosystems in Ecuador.

Understanding the behavior of cyanide in rivers is of utmost importance as it has a direct impact on the health of people who depend on these water sources. Cyanide contamination from gold mining activities poses a significant environmental threat to river ecosystems, particularly in southern Ecuador. This study aimed to investigate the behavior of cyanide when it enters contact with other metals in these rivers. Simulations were conducted to determine the speciation of cyanide, mercury, arsenic, lead, and manganese in a study area, taking into account the water temperature and pH at four locations. The findings revealed that CN-and HCN(aq) species were present in the research area. Additionally, mercury-cyanide (Hg(CN)2(aq), Hg(CN)3-), and manganese-cyanide (MnCN+) complexes were identified 3km downriver from the site where the mining activity is higher. These metal-cyanide complexes tend to dissociate quickly under weak acidic conditions, making them hazardous to the environment. This research is crucial, not only for the environment but also for human health, as it allows to predict toxicity risks for people supplied with this water source, emphasizing the potential harm to human health. This study highlights the importance of stringent regulations and effective monitoring practices to mitigate cyanide contamination and safeguard environmental and occupational health.

Evaluating ecological risks and metal bioavailability in post-dredging sediments of a wetland affected by artisanal gold mining

The evaluation of metal contamination, ecological risk, bioavailability, and the environmental dredging depth in sediments of two Colombian riverine systems impacted by artisanal gold mining and agricultural activities, was conducted following dredging processes. Results indicated significant contamination by Cd and Pb before dredging, based on the contamination factor (CF) and the geoaccumulation index (Igeo). Additionally, Cu and Hg were found to cause adverse biological effects according to sediment quality guidelines. Post-dredging, surface sediments exhibited a moderate ecological risk index (RI, 150–300), primarily due to increased contamination by Hg, Pb, and Cd. To mitigate this ecological risk (RI < 150), the environmental dredging depth needed to exceed 20 cm for all metals. On average, the bioavailable fraction increased 2.3 times within two months after dredging. However, the low environmental risk (%F1 = 1–10) calculated using risk assessment codes (RAC) indicates a potential risk due to metals entering the water column and bioaccumulating in organisms. These findings provide insights into the dynamics of metals and the impact of dredging activities on sediments in the Colombian Caribbean coast affected by various anthropogenic activities. The research underscores the importance of integrating sustainable practices in mining and agriculture to protect the ecological integrity of these riverine systems.

The Impact of Gold Mining Activities on the Environment and Community in Nagari Tambang, IV Jurai District, South Pesisir District

Nagari Tambang has an area of 14.97 𝐾𝑚2 . The population consists of 1,948 1,030 men and 918 women. Population density 130.12 per 𝐾𝑚2 . The types of mining in Nagari Tambang are coal, gold, and sirtukil. The coal mine is no longer operating, but gold and copper are still active. The local community carries out this mining activity. Problem activity mining will have an impact: the increased threat of landslides, loss of ground cover vegetation, soil erosion, increased sedimentation, decreased water quality, reduced forest area due to mining that has penetrated the forest, seawater pollution due to coal barge loading and unloading activities, as well as impacts on existing biota around the sea. Meanwhile, the effects on society include Washing waste, hazardous substances for human health, and environmental damage caused by mining. Research methods carried out are quantitative. The research location is in Nagari Tambang, IV Jurai District, Pesisir Selatan Regency. The research population is people living in Nagari Tambang, IV Jurai District, Pesisir Selatan Regency. Samples were taken purposively. Research results: 1. The Impact activity mining gold on the environment is: decreasing the quality environment, because impact of mining gold carried by the people of Nagari Tambang. Such as: a). Morphology land changed namely: layers soil, color land, structure soil, and consistency land. b). River water discharge is reduced Because water catchment in the hills Already decrease and amount plants stand forests is also decreasing. c). Public health is disturbed, such as their skin becoming dry and itchy and there are problems with their breathing. d). Haven't done it yet waste water treatment remainder from the separation process gold with material other. 2. Impact activity mining gold to society: a). Decreased interaction social with the community, b) Many young people in Nagari Tambang do not continue education to Higher Education, c). Life public No increase in a way significant, because mining use method traditional Not yet there is a business entity.

Mercury Contamination from Artisanal Small-scale Gold Mining Activities in Simpenan District, Sukabumi Regency, West Java, Indonesia

Mercury Contamination from Artisanal Small-scale Gold Mining Activities in Simpenan District, Sukabumi Regency, West Java, Indonesia

The effect of biostimulants and red mud on the growth and yield of shallots in post-unlicensed gold mining soil

Abstract Shallot production in West Kalimantan is still low. Land that has the potential for the development of shallots is the soil from post-unlicensed gold mining (PUGM). The soil at PUGM was exploited very extensively and can be used to develop shallots, but it is obstacled by low pH values and nutrient content. This research aims to investigate the impact of biostimulants and red mud on the growth and yield of shallots. The experiment was carried out in two stages: (1) investigated the ratio of the red mud and PUGM soil at the laboratory and (2) investigated the biostimulants and red mud effect on two varieties of shallots in a screen house. For the second experiment, there were three factors. The first factor was the biostimulant (0, 2, 3, and 4%); the second factor was the dose of red mud (0, 2, and 4 tons ha−1); and the third factor was the shallot varieties (Bima Brebes and Tajuk). The results of the first research indicated that the application of the red mud and PUGM soil in a ratio of 1:500 and 1:1,000 had a pH of 7.88 (slightly alkaline) and 7.24 (neutral), respectively. The second study found that a 2% concentration of biostimulant increased plant height and tuber count by 23.78 cm and 6.55 tubers, respectively. The Bima Brebes variety produced better fresh tubers weight clump−1 and dry tubers weight clump−1 than the Tajuk variety, with, respectively, 42.08 g (7.36 tons ha−1) and 32.60 g (5.71 tons ha−1). These findings show that the use of the biostimulants and red mud together in integrated management can help shallots grow and produce more, especially on PUGM land that has obstacles with low soil fertility. This research contributes to the identification of sustainable solutions for agricultural development in environments that have experienced severe land degradation, such as unlicensed gold mining activities.

Environmental and human health risk assessment of soils in areas of ore mineralization and past gold-mining activity.

The patterns of the potentially toxic elements (PTEs: Cr, Fe, Ni, Cu, Zn, As, Mo, Pb, Hg) distribution in soils were studied together with the health risk assessment in the area of ore mineralization, past gold activity, and tailing effects of the Sarala gold-ore group located in the Republic of Khakassia, Russia. High PTE concentrations were found in soils with the presence of potential negative impact on human health based on the following: local background investigation, according to statistics; geochemical, environmental, and human health risk calculations; and comparative analysis using international and local reference, such as continental crust, clarke, and permissible concentrations. Sources of PTE soil enrichment and pollution were statistically identified in ascending order of degree: geogenic (local background) < geogenic-technogenic (sites with geological exploration traces - trenches) < technogenic (waste tailings). The main pollutants are Hg and As which showed moderate to significant ecological risk. Negative impact of Cr on soils was found. The pollution degree and toxicity (moderate to significant) of other PTEs increase in the location of ore mineralization zone with exploration trenches and waste tailings. Arsenic poses a carcinogenic risk to adults and children upon contact with polluted soils and non-carcinogenic effect on children in areas affected by tailings and ore mineralization zone. The non-carcinogenic effect of Fe on children was found in soils of all sites. The results provide useful information regarding the studied PTEs and their impact on the environment and human health. Such information can be helpful for the state-level decision-making process when addressing solutions for contaminated areas.

Assessment of Radon Contamination in Drinking Water Sources Around Babban Tsauni Gold Mining Area, Federal Capital Territory, Nigeria

ABSTRACT Radon, a naturally occurring radioactive gas, is produced through the disintegration of radionuclides like uranium, thorium, or radium in the earth's crust. In this study, the radon levels and the annual effective dose from drinking water sources were assessed in Babban Tsauni, Gwagwalada, Nigeria, where artisanal gold mining is taking place. Water samples were collected and analyzed for 222Rn using liquid scintillation counter (Tri-Carb-LSA1000). The highest radon activity concentration was found in Dobi with a value of 3.215 Bq/L, while the lowest was found in Tsauni 7; 0.025 Bq/L. Both values were significantly below the maximum contamination level of 11.1 Bq/L and the world average value of 10 Bq/L, as established by USEPA and WHO respectively. The annual effective dose from ingesting radon was also below the permissible limit of 1 mSv/y for all age groups, the values for adult, children and infant ranged in mSv/y from 5.59E-07 to 2.35E-05, 8.39E-07 to 3.52E-05, 9.79E-07 to 4.11E-05 and 1.79E-07 to 2.55E-06, 2.68E-07 to 3.82E-06, 3.13E-07 to 4.46E-06 for ground and surface water sources respectively. This study concluded that the radon concentrations in the water sources remained within safe limits and that the anthropogenic activities of gold mining had no significant effect on the water sources.

Assessment of Radon Contamination in Drinking Water Sources Around Babban Tsauni Gold Mining Area, Federal Capital Territory, Nigeria

ABSTRACT Radon, a naturally occurring radioactive gas, is produced through the disintegration of radionuclides like uranium, thorium, or radium in the earth's crust. In this study, the radon levels and the annual effective dose from drinking water sources were assessed in Babban Tsauni, Gwagwalada, Nigeria, where artisanal gold mining is taking place. Water samples were collected and analyzed for 222Rn using liquid scintillation counter (Tri-Carb-LSA1000). The highest radon activity concentration was found in Dobi with a value of 3.215 Bq/L, while the lowest was found in Tsauni 7; 0.025 Bq/L. Both values were significantly below the maximum contamination level of 11.1 Bq/L and the world average value of 10 Bq/L, as established by USEPA and WHO respectively. The annual effective dose from ingesting radon was also below the permissible limit of 1 mSv/y for all age groups, the values for adult, children and infant ranged in mSv/y from 5.59E-07 to 2.35E-05, 8.39E-07 to 3.52E-05, 9.79E-07 to 4.11E-05 and 1.79E-07 to 2.55E-06, 2.68E-07 to 3.82E-06, 3.13E-07 to 4.46E-06 for ground and surface water sources respectively. This study concluded that the radon concentrations in the water sources remained within safe limits and that the anthropogenic activities of gold mining had no significant effect on the water sources.

Application of remote sensing methods to assess the environmental situation in the upper Lena River basin

This article addresses the problem of pollution in the Lena River caused by gold mining enterprises operating in its upper regions. It highlights the ongoing industrial exploitation of ore and placer gold deposits in five regions within the Siberian and Far Eastern federal districts. The most large-scale development is carried out in the Irkutsk region, Buryatia, and Yakutia. Further intensification of gold mining activities will result in significant negative impacts on the ecosystems of the upper reaches of the Lena River basin. In this context, the potential applications of Sentinel-2 satellite data for assessing the ecological conditions of river systems in Yakutia are being explored. The most common water indices, NDTI, AMWI, and Harma, were used in this study. The indices were applied to analyze the area of the Vitim River mouth, which contains the highest concentration of active gold mining license areas in the basin. Test sites were allocated on the Vitim and Lena rivers, as well as on Lake Okhninskoye for control purposes. Water indices were analyzed using the ArcGIS software package, and statistical data processing was conducted in the MS Excel program. It is revealed that the best results for estimating surface water turbidity in the area of the Vitim River mouth are obtained using the AMWI index. Spatial regularities are demonstrated, and the seasonal dynamics of turbidity in the studied water bodies are analyzed. The proposed methodology using the AMWI index can be applied for operational assessment of the state of water bodies in Yakutia under conditions of active anthropogenic pollution. This can facilitate timely implementation of preventive environmental protection measures.

Pertambangan Emas Tanpa Izin (Peti), Dampak Lingkungan, Sosial dan Ekonomi Serta Peranan Hukum Lingkungan di Kabupaten Lebong, Provinsi Bengkulu.

Unlicensed gold mining in Lebong Regency, Bengkulu Province, is a complex problem with significant environmental, social and economic impacts. Unlicensed gold mining in Lebong Regency, Bengkulu Province, is a complex problem with significant environmental, social and economic impacts. This research aims to analyze the social interaction patterns of the illegal workers in the region. illegal workers in the region. The research method was conducted by analyzing and description of the social interaction patterns of mine workers, with a focus on the subject of illegal miners in Lebong Tambang Village, North Lebong Regency. Sample The sample consisted of 100 illegal miners with probability sampling technique. Sampling technique. Research variables include environmental impacts andenvironmental and health impacts caused by unlicensed gold mining activities. Instruments The instruments used were surveys, interviews and documentation, with qualitative and quantitative data analysis. The data analysis used is qualitative and quantitative data analysis. The research results are expected to provide input for stakeholders, especially local governments, in formulating sustainable management of natural resources and the environment. sustainable management of natural resources and the environment. This research is expected to provide input for stakeholders, especially local governments, in formulating sustainable management of natural resources and the environment. This research is also expected to be a reference material for research and development on the topic in the future. Thus, this research As such, this research contributes to reducing the risk of environmental damage and pollution caused by illegal mining practices in Lebong District. caused by illegal mining practices in Lebong Regency.

Deciphering the Environmental Code: SEM-EDX Analysis of Lead and Mercury Distribution in Enhalus Acoroides From Kayeli Bay, Indonesia

Background: Illegal gold mining activities around Kayeli Bay have led to increased heavy metal contamination that has the potential to impair water quality and growth of Enhalus acoroides, an important seaweed species. This study aimed to investigate the distribution and concentration of heavy metals Pb and Hg in Enhalus acoroides organs (roots, rhizomes, and leaves) using SEM-EDX techniques and evaluate the impact of mining activities on the surface microstructure of these organs. Methods: Enhalus acoroides samples were collected from ten sampling points in Kayeli Bay, which were selected based on potential heavy metal contamination. SEM-EDX analysis was performed to assess the surface microstructure and distribution of heavy metals in the seaweed samples. Results: Results showed significant differences in Pb and Hg concentrations among samples from different locations, with Hg content consistently higher than Pb. Surface microstructure analysis showed morphological changes in roots, rhizomes, and leaves exposed to heavy metals, indicating environmental stress in Enhalus acoroides. Conclusion: This study confirmed the negative impact of heavy metal contamination on Enhalus acoroides in Kayeli Bay due to illegal gold mining activities. High concentrations of heavy metals, especially Hg, in seaweed organs indicate potential risks to marine ecosystem health and the sustainability of fisheries resources. These findings emphasize the need for stricter environmental monitoring and management to protect this important marine habitat from heavy metal pollution.

Megalithic structure from Burabay: Gold mining and cult communities of the Late Bronze Age of Northern Kazakhstan

The article presents the results of the research conducted at the megalithic monument located in the Burabay district of the Akmola region of the Republic of Kazakhstan. The monument received the name “Taskamal” (from the Kazakh language “Stone fortress”) from local residents and tourists due to its monumentality and characteristic masonry of granite blocks. The research focused on recording the architecture of the monument and understanding its cultural and chronological affiliation. The megalithic structure with a complex layout inscribed into the terrain. The study provides data on its key architectural elements - a long megalithic wall made of granite boulders, an embankment central platform, two ramps, an external platform, stone steles, relief images, quarries and a workshop. Analogies of individual elements of the complex, the construction techniques and its archaeological features, including depiction of a laying bull, allow us to preliminary date the object to the 2nd millennium BCE. We believe that the complex could be associated with the gold mining activities in Burabay during the Late Bronze Age and possibly was a place of worship for the miners.

Modeling the geochemical evolution of mine waters during mixing

This study focuses on assessing the hydrogeochemical processes influencing the mobility of dissolved metal and metalloid species during mine effluent mixing. Field samples were collected to characterize effluents at an active gold mine located in the Abitibi Greenstone belt in western Québec, Canada. Controlled laboratory mixing experiments were further performed with real effluents. In situ physicochemical parameters, concentrations of major dissolved ions and trace elements were analyzed. Mineralogical analyses were also performed on precipitates from the laboratory mixtures. The data were used for statistical analyses and for modeling the geochemical evolution of effluents using PHREEQC with the wateq4f.dat database (with modifications). The results suggest that the formation of secondary minerals such as schwertmannite, Fe(OH)3, and jarosite could significantly affect the concentrations of trace elements in effluents. The precipitation of secondary minerals immobilized trace elements through coprecipitation and sorption processes. The main limitations of the modeling approach used here include the evaluation of the ion balance for low pH samples with high Fe and Al concentrations and the omission of biological processes. The approach provides insights into the geochemical evolution of mine effluents and could be adapted to several mining sites as a tool for improving water management.

Influence of genetic polymorphisms of Hg metabolism and DNA repair on the frequencies of micronuclei, nucleoplasmic bridges, and nuclear buds in communities living in gold mining areas

Fishing communities living near gold mining areas are at increased risk of mercury (Hg) exposure via bioaccumulation of methylmercury (MeHg) in fish. This exposure has been linked to health effects that may be triggered by genotoxic events. Genetic polymorphisms play a role in the risk associated with Hg exposure. This study evaluated the effect of single nucleotide polymorphisms (SNPs) in metabolic and DNA repair genes on genetic instability and total hair Hg (T-Hg) levels in 78 individuals from "La Mojana" in northern Colombia and 34 individuals from a reference area. Genetic instability was assessed by the frequency of micronuclei (MNBN), nuclear buds (NBUDS), and nucleoplasmic bridges (NPB). We used a Poisson regression to assess the influence of SNPs on T-Hg levels and genetic instability, and a Bayesian regression to examine the interaction between Hg detoxification and DNA repair. Among exposed individuals, carriers of XRCC1Arg399Gln had a significantly higher frequency of MNBN. Conversely, the XRCC1Arg194Trp and OGG1Ser326Cys polymorphisms were associated with lower frequencies of MNBN. XRCC1Arg399Gln, XRCC1Arg280His, and GSTM1Null carriers showed lower NPB frequencies. Our results also indicated that individuals with the GSTM1Nulland GSTT1null polymorphisms had a 1.6-fold risk for higher T-Hg levels. The Bayesian model showed increased MNBN frequencies in carriers of the GSTM1Null polymorphism in combination with XRCC1Arg399Gln and increased NBUDS frequencies in the GSTM1Null carriers with the XRCC3Thr241Met and OGG1Ser326Cys alleles. The GSTM1+ variant was found to be a protective factor in individuals carrying OGG1Ser326Cys (MNBN) and XRCC1Arg280His (NPB); the GSTT1+ polymorphism combined with XRCCArg194Trp also modulated lower MNBN frequencies, while GSTT1+ carriers with the XRCC1Arg399Gln allele showed lower NPB frequencies. Consistent with GSTM1, GSTT1Null carriers with XRCC3Thr241Met showed increased NBUDS frequency. With the rise of gold mining activities, these approaches are vital to identify and safeguard populations vulnerable to Hg's toxic effects.

Business Strategy Effectiveness of SOE Gold Mining Pilot Project for Illegal Miners in Indonesia

The increasing challenges of illegal mining activities have prompted mining companies around the world to develop innovative strategies to address the problem. This research evaluates a pilot project at the Pongkor Gold Mine in Indonesia, where a cooperative model was implemented to formalise illegal gold mining activities. The research aims to assess the economic, environmental, and social impacts of integrating illegal miners into a formal cooperative framework. Quantitative data was collected through a structured questionnaire distributed to key stakeholders, including Pongkor employees, local community members, and cooperative members. In addition, qualitative insights were gained through semi-structured interviews with different levels of Pongkor management. The results show mixed perceptions regarding economic growth, with local community and cooperative members reporting significant benefits, while Pongkor employees remain sceptical. Environmental protection efforts are positively recognised by cooperative members, but less so by the wider community and employees. Increased social responsibility was widely recognised by all groups, highlighting improved social relations and stability. The findings underscore the need for better internal communication, structured engagement, and sustainable practices to ensure the long-term success of the co-operative model. This research provides a viable framework for transforming illegal mining activities into regulated and sustainable operations, which contribute to economic stability, environmental sustainability and social responsibility.

Repeated mining accounts for the majority of artisanal and small-scale gold mining activity in Southeastern Peru

Artisanal and small-scale gold mining (ASGM) is considered a leading cause of environmental degradation in the Amazon. Previous studies have only used deforestation to quantify total ASGM activity and have not considered that mining may occur multiple times in the same area. However, miners often revisit previously mined sites to extract additional gold, though the frequency and extent of this occurrence remains unquantified. This study is the first to quantify repeat ASGM in Madre de Dios, Peru, and to identify which factors best predict revisitation. We found that nearly two-thirds of total ASGM activity in this region is repeat mining. When repeat mining activity is accounted for, we found that 249 488 ha were mined from 1984–2021, which is 265% more than activity estimates based on deforestation due to initial ASGM alone. Random Forest modeling showed that the designation, region, size, and type of a mine were the most important predictors of repeat mining. We suggest that repeat mining must be considered for a more comprehensive view of ASGM activity and its environmental impacts.