Distribution, sources, and transport pathways of atmospheric gaseous elemental mercury: interhemispheric differences during a transatlantic cruise from the Baltic Sea to the Southern Ocean in 2019-2020.

ABSTRACT Mercury (Hg) from artisanal and small-scale gold mining (ASGM) remains a source of long-term soil contamination in the Brazilian Amazon, yet its long-term persistence and controlling factors in deactivated sites are still poorly understood. This study evaluates total mercury (THg) concentrations in surface soils from three ASGM sites in the Tapajós region (active, deactivated in 2024, and deactivated for approximately 30 years), with a focus on the role of soil properties in Hg retention. Results show that the site deactivated for ~30 years still exhibits elevated THg concentrations (27 to 8,862 ng g−1; median = 324 ng g−1) and ecological risk levels above regulatory thresholds, highlighting the long-term environmental legacy of ASGM. In contrast, recently deactivated and active sites presented average THg concentrations near the background value of 178 ng g−1 (134 ± 44 ng g−1 and 77 ± 93 ng g−1, respectively), with localized increases near operational structures. In the long-term deactivated site, THg concentrations were strongly associated with the proportion of fine particles (R2 = 0.73) and positively correlated with water‑holding capacity (WHC, ρ = 0.54, p < .01), indicating higher THg concentrations in finer-textured soils. These findings suggest that Hg persistence in this site is primarily associated with geoenvironmental controls rather than natural attenuation processes. Soil heterogeneity likely promotes the formation of microenvironments that are favorable to Hg retention and may limit its remobilization, even under high rainfall conditions. Overall, this study advances the understanding of Hg behavior in tropical post-ASGM landscapes by demonstrating that contamination persistence can be closely linked to substrate properties and small-scale variability. Our findings have direct implications for environmental monitoring and risk assessment, highlighting the need for site-specific approaches to address the long-term impacts of ASGM in the Brazilian Amazon.

Suriname has been certified malaria-free by WHO on June 30th 2025. In the post-elimination era, malaria is still requiring full attention of the public health system. This is in particular due to the malaria burden in neighbouring countries and the intense migration across borders related to small scale artisanal gold mining, which poses a risk for re-establishment of malaria into the country. Throughout the process of achieving certification of malaria elimination, the National Malaria Program implemented a range of strategies to maintain the zero transmission status. This manuscript describes and explains these strategies, highlighting the recent addition of individual targeted drug administration and presumptive antimalarial treatment. In the context of maintaining the elimination status of Suriname, the regional malaria situation is presented and the importance of a regional strategy in the ongoing fight against malaria addressed. Suriname is extremely susceptible for re-establishment of malaria. The National Malaria Elimination Task Force implemented innovative strategies, adapted to the dynamics of malaria importation. Next to these national actions, it is pivotal that the malaria situation in the Guiana Shield is addressed with a regional effort.

African soils face increasing levels of metal pollution due to industrialization, artisanal mining activities, improper waste management, and enhanced agricultural productivity. However, unlike many organic pollutants, heavy metals do not degrade naturally and therefore persist in environmental systems for prolonged periods. Heavy metals accumulate over many decades in the soil and bioaccumulate through the food chain causing severe health complications such as cancer, kidney problems, and neurological impairment. This paper reviews the current literature on the origin, prevalence, and behavior of the main pollutants Pb, Cd, Cr, As, Hg, and Cu. The major phytoremediation methods including phytoextraction, rhizofiltration, phytostabilization, and phytovolatilization are highlighted alongside in planta screening methods for hyperaccumulating plants including Berkheya coddii (Ni) and Haumaniastrum robertii (Co). The paper evaluates various enhancement techniques such as the use of chelators, Rhizobium inoculations, and genetic modifications. The significance of these approaches in tropical and subtropical climates is discussed. The paper suggests a holistic framework involving empirical kinetic modeling, geospatial machine learning (random forest, kriging), and molecular omics in prediction modeling. Major hurdles in such predictions include lack of field-based verification of the models, biotechnology safety of genetically modified (GM) organisms, and inadequate regulations. Future perspectives emphasize community-driven phytomining, biomass recycling, and resilient phytoremediation solutions.

Artisanal and small-scale gold mining (ASGM) generates complex metal mixtures, yet their biological effects remain poorly characterized in high-altitude populations, where occupational exposure occurs against a hypoxic environmental background. This study evaluated 49 occupationally exposed gold miners from the Vetas-California mining district, near the Santurbán páramo in Colombia, and 25 non-exposed individuals from a comparable high-altitude area. Hair concentrations of essential and toxic elements were quantified by ICP-MS, and serum catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH), oxidized glutathione (GSSG), and the GSH/GSSG ratio were assessed. Miners showed a distinct multielement profile, with a higher toxic-metal burden and a dominant mixture mainly characterized by Fe, Mn, As, Pb, Cd, and Hg. CAT and SOD activities did not differ markedly between groups, although SOD activity decreased along the main exposure gradient among exposed workers. In contrast, glutathione-related biomarkers showed a more consistent exposure-related pattern, with higher GSSG and a lower GSH/GSSG ratio, suggesting a shift toward a more oxidized glutathione redox status. Together with positive within-group associations between selected elements and the GSH/GSSG ratio, these results are consistent with a mixture-associated perturbation of glutathione redox homeostasis, with heterogeneous adaptive responses. Overall, this study supports the use of integrated biomonitoring strategies and highlights glutathione-related markers as potential indicators of early redox perturbation in high-altitude mining populations.

Maternal anemia and prenatal exposure to neurotoxic metals are widespread in low- and middle-income countries and may affect early childhood development. In Suriname, where mercury contamination from artisanal gold mining and social disparities coexist, we examined associations between maternal anemia, prenatal exposure to mercury (Hg), lead (Pb), manganese (Mn), selenium (Se), and cadmium (Cd), and early neurodevelopment. The study included 755 pregnant women and 644 children (10-26 months) from the Caribbean Consortium for Research in Environmental and Occupational Health (CCREOH) cohort. Maternal anemia was defined using WHO criteria for Hb, metals were measured in maternal blood, and child development was assessed using the Bayley Scales of Infant and Toddler Development, third edition (BSID-III-NL). Analyses used non-parametric tests, correlations, and multivariable regression. Anemia, though common (34%), was not independently associated with cognitive, language, motor, or social-emotional outcomes. However, iron status was not directly measured; therefore, the absence of an observed association should not be interpreted as evidence that maternal iron deficiency is unrelated to early neurodevelopment. Pb showed the most consistent associations, with higher prenatal levels predicting poorer cognitive, motor, and language scores. Hg demonstrated weaker but significant negative associations with several domains, while Mn and Cd showed limited direct effects. Interaction analyses suggested a potential modifying role of Se in certain metal-neurodevelopment associations; however, these findings require confirmation in future studies. Overall, these results suggest that prenatal exposure to neurotoxic metals and sociodemographic disparities may be important contributors to variation in early neurodevelopment in this population, but causal inferences cannot be made from this cross-sectional analysis.

Access to clean water in mining regions is frequently compromised by contaminants, including naturally occurring radioactive materials. This study investigates radiological contamination of drinking water sources in the Okaba coalfield, Nigeria, where artisanal coal mining operations potentially mobilize radionuclides into surface and groundwater. Activity concentrations of 238U, 232Th, and 40K were quantified in 24 water samples using high-purity germanium gamma spectrometry. Results revealed significant radionuclide enrichment, with mean activity concentrations of 104.80 ± 15.2 Bq L−1 for 238U, 51.49 ± 8.7 Bq L−1 for 232Th, and 719.64 ± 89.4 Bq L−1 for 40K. These values substantially exceed global average concentrations for natural waters and are notably higher than those reported in other Nigerian mining regions. Radiological hazard indices, including radium equivalent activity (mean = 573.87 Bq L−1) and the internal hazard index (exceeding unity in 29% of samples), indicated significant potential health risks. Strong positive correlation between 238U and 232Th (r = 0.82, p < .01) and spatial analysis linking elevated concentrations to proximity to mining activities implicate anthropogenic mobilization as the primary source of uranium and thorium enrichment. Age-specific annual effective dose (AED) via ingestion exceeded the World Health Organization reference level of 0.1 mSv y−1 in 100% of samples for infants, 96% for children, and 92% for adults. Infants emerged as the most vulnerable cohort, with mean AED of 1.75 mSv y−1, approximately 17.5 times the guideline value. These findings underscore a serious public health concern and highlight the urgent need for targeted monitoring, remediation strategies, and policy interventions in artisanal and small-scale mining regions.

ABSTRACT Industrialized mining and oil drilling have engendered profound infrastructural and environmental violence throughout Africa in the twentieth century. Rapacious resource extraction has resulted in toxic wastelands, land dispossession, and jeopardized well-being. As ways of resisting extractive violence and longstanding environmental dispossession, some communities have made attempts to repossess and ‘legitimize’ the natural resources in their localities through practices of artisanal extraction. Drawing from examples of jerabos mining waste dumps on the Zambian Copperbelt and kpo fire crude oil refining in the Niger Delta, this article conceptualizes these artisanal practices as a form of environmental resistance to pervasive extractive violence. Through ethnographic, archival, and newspaper sources, we analyze the politics of environmental resistance in extractive geographies, focusing on how communities interact with, respond to, and resist infrastructural violence. Adopting an historical approach, the article shows the interdependencies and tensions between industrial and artisanal forms of resource extraction. While artisanal extraction emerged as a form of environmental resistance, it ultimately deepens the environmental crisis in these localities. We contribute to debates in political ecology and the environmental humanities by deconstructing artisanal mining and oil drilling as forms of environmental resistance to global capitalist extractivism.

Multi-matrix biomonitoring of human exposure to extreme levels of atmospheric mercury in urban artisanal gold mining areas: A Colombian case study.

Food insecurity and depressive symptoms among miners in Ghana: The role of psychosomatic factors

Fierce debates rage over ‘what to do’ about child labour in artisanal and small-scale mining (ASM). Long decried as a site of exploitation, ASM is demonised by much of the international child protection architecture as an archaic relic in need of eradication. By contrast, working children’s movements, civil society advocates, and sympathetic academics all argue that the picture is more complex, that child work, including in ASM, can bring many benefits, and thus that regulation is better than repression. To this more progressive, yet still reformist, strand of argument has recently been added a more radical alternative, calling for massive redistribution to address ‘the root causes of the root causes’. This paper reviews the field of competing representations of and proposed responses to child labour in ASM. It argues that although the repressive strand remains hegemonic, the reformist is gaining ground, while the radical is pointing in increasingly progressive political directions. The paper marks, in 2025, not only the point at which all child work in ASM should have been eradicated, according to the United Nations’ Sustainable Development Goals, but also the 20th anniversary of the International Labour Organisation’s seminal take on the issue, A Load Too Heavy .

• Mineral exhaustion and mechanization drive ASGM towards increasingly complex deposits. • Extracting these resource sustainably requires knowledge beyond trial-and-error. • Knowledge creation is vital for transitioning to sustainable practices in ASGM. • Increasingly complex kn owledge requirements exacerbate inequalities in ASGM. • The role of the natural environment in ST can be examined through knowledge creation. Artisanal and small-scale gold mining (ASGM) is a key economic sector in Tanzania and the global South. Its predominant extraction method, mercury amalgamation, is valued for low cost and minimal skill requirements but poses severe risks to human health and the environment. ASGM is undergoing two major transformations: depletion of easily accessible deposits and growing mechanization. Cyanide leaching has emerged as a prominent alternative to mercury, promoted as a less harmful option yet still associated with significant environmental and health risks. This study situates mercury and cyanide in ASGM within the Geography of Sustainability Transitions (GeoST) to examine how changes in the natural environment like mineral exhaustion influence extraction processes and sustainability. We adopt knowledge creation processes as an analytical lens to explore how miners develop and apply knowledge to adapt to transforming environmental and technological contexts. Using a mixed-methods approach combining qualitative interviews and a quantitative survey conducted in Tanzania, we find that more efficient and relatively less environmentally harmful practices require complex knowledge of the natural environment and technologies that go beyond the sensory-based, experiential learning typical of mercury amalgamation. This knowledge gap sustains mercury use and exacerbates inequalities between miners with and without technical expertise. Our findings highlight the importance of linking knowledge creation with environmental conditions to support transitions away from highly unsustainable practices like mercury in ASGM.

Mental health distress, perceived stress, and subjective health status in informal mining: Evidence from artisanal miners in Ghana

Unpacking the mechanisms linking generalized anxiety symptoms and global subjective health status among artisanal miners in Ghana

• Predominant ASGM research focus on environmental state and impacts. • Ecological and social systems are studied in isolation. • Little emphasis on the spatial extent of ASGM mediated pollution. • Need for future ASGM research to determine mechanistic interactions between DPSIR elements and how they shape social-ecological systems. Artisanal and small-scale gold mining (ASGM) has long been a lucrative source of income globally. Today, ASGM is concentrated in low- and middle-income countries, and its extraction and processing have detrimental consequences for the environment as well as human health and livelihoods. We systematically reviewed 145 articles published between 1978 and 2024 on the effects of ASGM on social and ecological systems worldwide. Using the Driver-Pressure-State-Impact-Response (DPSIR) framework, we critically examine where past research has focused and where it has fallen short in understanding the mechanisms that drive impacts and responses to ASGM. Research has predominantly focused on changes in the state of environmental systems and subsequent ecological and socio-economic impacts. In contrast, the driving factors of ASGM and response strategies have been much less studied, while understanding of interactions across all DPSIR elements remains lacking. Furthermore, research has taken a local lens, giving little attention to the spatial extent of ASGM activities and their impacts. Our analysis thus reveals important gaps in understanding the complex mechanisms driving ASGM adoption and the extent to which responses can mitigate negative impacts. To inform effective policy interventions, future research should emphasize mechanistic and spatial interactions of DPSIR elements and how they shape social-ecological systems.

Mercury management at artisanal and small-scale gold mines in sub-Saharan Africa: Some key challenges for donors and policymakers

• Lima beans ( Phaseolus lunatus ) reduced tailings cyanide from ∼33 to 13.4 mg/kg. • Cyanide accumulated mainly in roots, suggesting root-zone attenuation. • First-order kinetics predicted remediation (R 2 = 0.921). • Safe cyanide levels achievable in ∼130 days at 10 plants/m 2 . Cyanide contamination from gold mine tailings poses significant ecological and human health risks, particularly in artisanal and small-scale mining regions of Uganda. This study evaluated the phytoremediation potential of lima beans ( Phaseolus lunatus) for cyanide-laden tailings obtained from Greenstone Mining Limited under field conditions. Experimental plots were established at planting densities of 0, 5, 10, and 15 plants/m 2 and monitored over an 84-day growth period. Soil and plant tissue cyanide concentrations were quantified using a titrimetric method. Cyanide attenuation increased with planting density, reaching 42.6 ± 1.8%, 54.7 ± 1.4%, and 59.1 ± 0.8% at 5, 10, and 15 plants/m 2 , respectively, compared to 3.4 ± 1.2% in the unplanted control. Cyanide removal was most pronounced during the vegetative growth stage, coinciding with increased root biomass development. Tissue analysis showed cyanide distribution in the order of roots > stems > leaves > seeds, suggesting that attenuation occurred predominantly within the root zone through combined plant uptake, in situ phytodegradation, and rhizosphere-mediated processes, with limited translocation to edible tissues. First-order kinetic modeling provided the best fit to the 10 plants/m 2 treatment (R 2 = 0.921). Based on this model, the estimated indicative remediation time to reach the Canadian soil quality guideline limit for cyanide of 8 mg/kg is approximately 130 days. These findings demonstrate that P. lunatus significantly enhances cyanide attenuation beyond natural background processes and highlight its potential as a low-cost, field-applicable phytoremediation strategy for cyanide-contaminated mine tailings in tropical environments.

The allure of the “white gold”: The lithium rush, artisanal mining mobilities, and the politics of exclusion in Zimbabwe, 2020-2024

Comprehensive sub-chronic toxicological profiling of illegal artisanal small-scale mining-polluted river bodies in four regions of Ghana.

Does Licensing Matter? Cyanide Handling, Cyanidation Wastewater Treatment, and Tailings Management in Gold Leaching Plants in Siaya County, Kenya.