Methylmercury (MeHg) in the most consumed fish in a municipality of La Mojana, Colombia

La Mojana is a biodiverse area of wetlands that offers environmental services to its inhabitants. Despite its ecological relevance and for the food security of its inhabitants, this ecoregion has been strongly impacted by contamination from mining that takes place in the riverbeds that drain into it. Therefore, it is necessary to monitor the levels of MeHg in foods of relevance to the population of the area, such as fish. Thus, current research seeks to determine the levels MeHg in the most consumed ichthyofauna in the region and its possible impacts on public health. Therefore, MeHg concentrations were determined in the most consumed fish species in San Marcos, Colombia. Using cold vapor atomic absorption spectrophotometry (CVAAS) the concentrations of MeHg in the dorsal muscle of the most consumed species were quantified. Pseudoplatystoma magdaleniatum, Plagioscion surinamensis, and Hoplias malabaricus registered the highest levels of MeHg with concentrations of 0.396 ± 0.025 µg/g; 0.377 ± 0.049 µg/g and 0.355 ± 0.028 µg/g, respectively. No species exceeded the maximum permissible concentration in the muscle of 0.5 µg/g for fresh fish established by the European Union. However, all carnivorous species exceed the threshold for a vulnerable population of 0.2 µg/g. It is concluded that the ichthyofauna of the Mojana is contaminated with MeHg, which constitutes a public health problem and a risk factor for the fauna and the inhabitants of this region, due to the habitual consumption of contaminated fish.

La Mojana es una zona biodiversa de humedales que ofrece servicios ambientales a sus habitantes. A pesar de su relevancia ecológica y para la seguridad alimentaria de sus pobladores, dicha ecorregión ha sido fuertemente impactada por la contaminación, proveniente de la minería que se desarrolla en los cauces de los ríos, que drenan en ella. Por lo anterior, es necesario monitorear los niveles de MeHg, en alimentos de relevancia para la población de la zona, como los peces. Así, la actual investigación busca determinar los niveles de MeHg en la ictiofauna de mayor consumo en la región y sus posibles impactos en la salud pública. Por lo tanto, se determinaron las concentraciones de MeHg en las especies de peces más consumidas en San Marcos, Colombia. Usando espectrofotometría de absorción atómica por vapor frío (CVAAS), se cuantificaron las concentraciones de MeHg, en músculo dorsal de las especies más consumidas. Pseudoplatystoma magdaleniatum, Plagioscion surinamensis y Hoplias malabaricus registraron los niveles más altos de MeHg, con concentraciones de 0,396 ± 0,025 µg/g; 0,377 ± 0,049 µg/g y 0,355 ± 0,028 µg/g, respectivamente. Ninguna especie superó los valores de concentración máxima permisible en músculo de 0,5 µg/g, para peces frescos, que establece la Unión Europea; sin embargo, todas las especies carnívoras superaron el umbral para población vulnerable, de 0,2 µg/g. Se concluye, que la ictiofauna de La Mojana, se encuentra contaminada con MeHg, lo que constituye un problema de salud pública y factor de riesgo para la fauna y los habitantes de esta región, debido al consumo habitual de peces contaminados.

Revegetación natural de áreas afectadas por minería de oro en la selva pluvial tropical del Chocó, Colombia / Natural revegetation of areas impacted by gold mining in the tropical rain forest of Chocó, Colombia

Introducción: La minería de oro a cielo abierto ocasiona impactos drásticos sobre los bosques naturales en regiones tropicales de alta biodiversidad, y la eficiencia de "revegetación", un proceso de resembrar y reconstruir el suelo, continúa siendo poco estudiado. Objetivo: Evaluar el efecto del tiempo sucesional y la distancia al bosque de referencia sobre la estructura biológica y composición de especies en minas de oro revegetadas. Métodos: Realizamos inventarios de vegetación en minas abandonadas en el bosque tropical lluvioso de Chocó, Colombia. Las minas contaban con 6, 10, 15, 19 y 24 años de sucesión natural. En cada escenario, establecimos cuatro parcelas de 2×50 m: a 50 m y 100 m de distancia desde el borde bosque-mina (ecotono). Resultados: Se identificaron 300 especies (193 géneros y 75 familias). La riqueza, diversidad y equitatividad cambian poco con el tiempo sucesional en las minas, pero alcanzan valores superiores en el bosque de referencia. La composición de especies es similar entre las minas con distinto tiempo sucesional, pero difiere ampliamente del bosque de referencia (solo 7 % de semejanza). La calidad del sustrato y las estrategias reproductivas de plantas herbáceas (principalmente Cyperaceae y Melastomataceae) y arbóreas (Cespedesia spathulata y Miconia reducens) que crecen espontáneamente en las minas, juegan un papel importante en la revegetación natural temprana. Conclusiones: 24 años de sucesión natural es poco tiempo para apreciar una recuperación sustancial de la vegetación en las minas si se compara con el bosque, y la distancia desde el ecotono parece no tener efecto significativo; sin embargo, la calidad de sustrato y estrategias reproductivas de plantas herbáceas son importantes en la etapa temprana de recuperación de las áreas impactadas por la minería de oro en Chocó.

Introduction: Open pit gold mining causes drastic impacts on natural forests in tropical regions of high biodiversity, and the efficacy of "revegetation", a process of replanting and rebuilding the soil, is still poorly studied. Objective: To evaluate the effect of successional time, and distance to the reference forest, on the biological structure and species composition of revegetated gold mines. Methods: We inventoried the adjacent forest and abandoned gold mines in the tropical rain forest of Chocó, Colombia. The mines had 6, 10, 15, 19 and 24 years of natural succession. In each scenario, we set four 2 × 50 m plots: two 50 m and two 100 m from the forest-mine edge (ecotone). Results: We identified 300 plant species (193 genera, 75 families). The richness, diversity and evenness changed little with successional time in the mines but reached higher values in the forest. The species composition was similar between the mines with different successional times but differed widely from the forest (only 7 % similarity). The substrate quality and reproductive strategies of herbaceous plants (mainly Cyperaceae and Melastomataceae) and trees (Cespedesia spathulata and Miconia reducens) that grow spontaneously in the mines, play an important role on the early natural revegetation. Conclusions: The 24 years of natural succession have been insufficient to reach a community of a complexity similar to that of the forest, and distance from the ecotone has no significant effect; however, the substrate quality and reproductive strategies of herbaceous plants are important in the early stages of mine recovery in the Chocó.

The cost of gold: Mercury contamination of fishes in a Neotropical river food web

In South America, mercury contamination due to gold mining operations is a threat to both biodiversity and human health. We examined mercury (Hg) concentrations in fishes that constitute important subsistence fisheries from mined and non-mined tributaries in the middle Mazaruni River, Guyana. Mercury concentrations and trophic food web structure (based on carbon and nitrogen stable isotopes) were characterized for primary basal sources and 39 fish species representing seven trophic guilds. Fishes collected at mined sites had higher mercury concentrations; piscivores and carnivores had the highest Hg concentrations and exhibited significant Hg biomagnification. Our results showed that medium- to large-bodied fishes commonly eaten by local people contained Hg values that exceed the World Health Organization (WHO) criteria, and pose a health concern for riverine communities along the Mazaruni River that depend on fish as their main source of protein. Further research to determine the sources of Hg contamination and how it affects human health in this neotropical river must become a top priority. In addition, more research on how Hg contamination impacts the fishes themselves and overall aquatic biodiversity is also needed in the Mazaruni River which has both high fish endemism and diversity.(AU)

Na América do Sul, a contaminação por mercúrio devido às operações de mineração de ouro é uma ameaça à biodiversidade e à saúde humana. Nós examinamos as concentrações de mercúrio (Hg) em peixes que constituem importantes pescarias de subsistência em afluentes minerados e não minerados no médio rio Mazaruni, Guiana. As concentrações de mercúrio e a estrutura trófica da teia alimentar (baseada em isótopos estáveis ​​de carbono e nitrogênio) foram caracterizadas para fontes basais primárias e 39 espécies de peixes representando sete guildas tróficas. Os peixes coletados em locais minerados tiveram maiores concentrações de mercúrio; piscívoros e carnívoros tiveram as maiores concentrações de Hg e exibiram biomagnificação significativa de Hg. Nossos resultados mostraram que peixes de corpo médio a grande comumente consumidos pela população local continham valores de Hg que excedem os critérios da Organização Mundial de Saúde (OMS) e representam uma preocupação para a saúde das comunidades ribeirinhas ao longo do rio Mazaruni que dependem dos peixes como sua principal fonte de proteína. Outras pesquisas para determinar as fontes de contaminação por Hg e como isso afeta a saúde humana neste rio neotropical devem se tornar uma prioridade. Além disso, mais pesquisas sobre como a contaminação por Hg impacta os próprios peixes e a biodiversidade aquática em geral também são necessárias no rio Mazaruni, que tem alto endemismo e diversidade de peixes.(AU)

Valoración participativa de impactos socioambientales y sanitarios en minería de oro: Buriticá (Antioquia), Colombia / Participatory assessment of socio-environmental and health impacts in gold mining: Buriticá (Antioquia), Colombia / Avaliação participativa de impactos socioambientais e sanitários em mineração de ouro: Buriticá (Antioquia), Colômbia

Resumen Objetivo: Conocer la valoración que habitantes de Buriticá, Antioquia, hacen de los impactos socioambientales y sanitarios por la actividad minera aurífera en la región. Metodología: Estudio investigativo de método mixto, con enfoque cualitativo y cuantitativo, con participación de funcionarios de la Alcaldía, habitantes de zona rural y de la cabecera municipal, y personal administrativo y operarios de una asociación minera del municipio en proceso de legalización. Los actores identificaron, valoraron, priorizaron y categorizaron los impactos percibidos, para lo que se utilizaron los métodos Leopold (1971) y Empresas Públicas de Medellín-Arboleda (1985) modificados. Resultados: La migración de mineros a Buriticá generó explotación aurífera informal con: impactos críticos (76-100 puntos) de contaminación de aguas, choque cultural, pérdida de identidad, aumento de alcoholismo, drogadicción, prostitución y delincuencia; impactos severos (50-75 puntos) de colapso de servicios públicos, aparición de plagas, construcciones de alto riesgo, tala de árboles y migración de animales; impactos positivos, como aumento del sentido de pertenencia de las personas autóctonas, incremento del comercio y del empleo, y aprendizaje del hospital para superar condiciones de capacidad instalada frente a la atención de urgencias, traumas, accidentes e intoxicaciones. Conclusión: El auge de la minería causó impactos identificados por diferentes actores: estos visualizaron que el aumento de la población foránea no es solo uno de los impactos más significativos que se han dado a partir de la minería, sino que también es el causante de muchos otros que han surgido en los tres componentes evaluados (social, ambiental y sanitario).

Abstract Objective: To determine the assessment of Buriticá's (Antioquia) inhabitants on the socio-environmental and health impacts of gold mining activity in the region. Methodology: Mixed method research study with a qualitative and quantitative approach, with the participation of officials from the Mayor's Office, inhabitants of rural areas and the municipal area, and administrative personnel and operators of a mining association in the municipality in the process of legalization. The actors identified, assessed, prioritized and categorized the perceived impacts, for which the modified Leopold (1971) and Empresas Públicas de Medellín-Arboleda (1985) methods were used. Results: The migration of miners to Buriticá generated informal gold mining that in turn generated: critical impacts (76-100 points) in terms of water contamination, culture shock, loss of identity, increased alcoholism, drug addiction, prostitution and crime; severe impacts (50-75 points) in terms of the collapse of public services, appearance of pests, high-risk buildings, felling of trees and animal migration; positive impacts, such as an increase in the sense of belonging of indigenous people, an increase in commerce and employment, and hospital training to overcome conditions of installed capacity in the face of emergency care, trauma, accidents and poisoning. Conclusion: The mining boom caused impacts identified by different actors: these visualized that the increase in the foreign population is not only one of the most significant impacts that have occurred from mining, but is also the cause of many others that have emerged in the three components evaluated (social, environmental and health).

Resumo Objetivo: Conhecer a avaliação que os habitantes de Buriticá, Antioquia, fazem dos impactos socioambientais e sanitários devido à atividade de mineração aurífera na região. Metodologia: Foi usado o método misto em pesquisa, com abordagem qualitativa e quantitativa, com a participação de funcionários da prefeitura, habitantes da zona rural e do município, pessoal administrativo e trabalhadores de uma associação mineira do município em processo de legalização. Foram identificados, avaliados, priorizados e categorizados os impactos detectados, usando os métodos Leopold (1971) e Empresas Públicas de Medellín -Arboleda (1985) modificados. Resultados: A migração de mineiros à Buriticá gerou uma exploração aurífera informal com impactos críticos (76-100 pontos), contaminação de águas, choque cultural, perda da identidade, aumento de alcoolismo, dependência de drogas, prostituição e delinquência; impactos severos (50-75 pontos) de colapso de serviços públicos, surgimento de pragas, construções de alto risco, derrubada de árvores e migração de animais; impactos positivos como aumento do sentimento de pertencimento das pessoas autóctones, aumento do comércio e do emprego e a aprendizagem do hospital para superar condições de capacidade derivada da atenção de urgências, traumas, acidentes e intoxicações. Conclusão: O auge da mineração causou impactos identificados por diferentes fatores: é evidente que o aumento da população recém-chegada não é só um dos impactos mais significativos derivados da mineração, mas é também o causador de muitos outros que apareceram nos três componentes avaliados (social, ambiental e sanitário).

Biodégradation of cyanide via recombinant cyanide dehydratase from Bacillus pumilus expressed heterologously in Escherichia coli / Biodegradación de cianuro por la enzima cianuro dihidratasa de Bacillus pumilus expresada heterologamente en Escherichia coli

ABSTRACT Despite its high toxicity, cyanide is used in several industrial processes, and as a result, large volumes of cyanide wastewater need to be treated prior to discharge. Enzymatic degradation of industrial cyanide wastewater by cyanide dihydratase, which is capable of converting cyanide to ammonia and formate, is an attractive alternative to conventional chemical methods of cyanide decontamination. However, the main impediment to the use of this enzyme for the biodegradation of cyanide is its intolerance to the alkaline pH at which cyanide waste is kept and its low thermoresistance. In the present study, the catalytic properties of whole Escherichia coli cells overexpressing a cyanide dihydratase gene from Bacillus pumilus were compared to those of the purified enzyme under conditions similar to those found in industrial cyanide wastewater. In addition, the capacity of whole cells to degrade free cyanide in contaminated wastewater resulting from the gold mining process was also determined. The characteristics of intracellular enzyme, relative to purified enzyme, included increased thermostability (>60% activity at 50°C), as well as greater tolerance to heavy metals, and to a lesser extent pH (20% activity remaining at pH 9.0) On the other hand, enzymatic degradation of 70% of free cyanide (initial concentration 528 mM) in the industrial sample was achieved only after dilution. Nevertheless, the increased thermostability observed for intracellular CynD suggest that whole cells of E. coli overexpressing CynD are suited for process that operate at elevated temperatures (50°C), a limitation observed for the purified enzyme.

RESUMEN A pesar de su alta toxicidad, el cianuro es usado en diversos procesos industriales, y como resultado, grandes volúmenes de aguas residuales de cianuro deben ser tratados antes de su descarga. Una alternativa atractiva a los métodos químicos convencionales de descontaminación es la degradación enzimática por la enzima cianuro dihidratasa, la cual es capaz de convertir cianuro en amonio y ácido fórmico. No obstante, la inactivación de esta enzima a pH superior a 8.5 y su poca termoestabilidad han sido el principal impedimento para la implementación exitosa de esta alternativa de biorremediación. En el presente estudio, las propiedades catalíticas de células completas de Escherichia coli que sobre expresan el gen de cianuro dihidratasa de Bacillus pumilus se estudian bajo condiciones similares a las encontradas en aguas residuales industriales de cianuro y los resultados se discuten en comparación con las de la enzima purificada. Además, se determinó la capacidad de las células completas para degradar el cianuro libre en aguas residuales resultantes del proceso de extracción de oro. Las características de la enzima intracelular, relativa a la enzima purificada, incluyeron un incremento en la termoestabilidad (>60% actividad a 50°C), así como mayor tolerancia a metales pesados y en menor medida al pH (20% actividad residual a pH 9.0). Por otra parte, la degradación enzimática del 70% del cianuro libre en la muestra industrial (concentración inicial 528 mM) se logró solo después de la dilución de la muestra. Sin embargo, el incremento en la termoestabilidad observado para CynD intracelular sugiere que las células completas de E. coli que sobre expresan CynD son adecuadas para procesos que operan a temperaturas elevadas (50°C), una limitación observada para la enzima purificada.

Potentially toxic elements in soils and contamination indices at the serra pelada gold mine, Para, Brazil / Elementos potencialmente tóxicos em solos e índices de contaminação na área de mineração de ouro de serra pelada, Pará, Brasil

The large surface stacking volume of waste and tailings at the Serra Pelada gold mine, with a high content of potentially toxic elements (PTEs), has led to environmental damage in the area, which continues to this day and is yet to be measured. Total and available Cu, Mo, Pb, and Zn and an indicator index was formulated for soil contamination in the artisanal mining area of Serra Pelada, Amazônia, Brazil. To obtain these data, six soil samples were collected surrounding the lake formed from the mining trenches and one from a forest area outside the influence of mining activities. Metal solubilization and partial extraction were conducted by aqua regia and 0.5 mol L-1 HCl, respectively, followed by detection using argon plasma optical emission spectrometry. All PTEs showed total contents above the quality reference values for soils in the state of Para. The available fractions of Cu, Pb, and Zn were higher than the concentrations expected for Para in forest soils. The total Cu contents were above the value of prevention defined by the National Council of Environment. In general, there was Mo enrichment (41.0) > Cu (3.5) > Pb (1.4), indicating that the areas had been contaminated by PTEs a resulting from human activity.

O empilhamento superficial de volume expressivo de rejeito e estéril, com alto teor de elementos potencialmente tóxicos causou danos ambientais até hoje não mensurados. Neste contexto, constituiu-se objetivo deste trabalho, avaliar os teores totais e disponíveis de Cu, Mo, Pb e Zn e determinar índices indicadores de contaminação em solos na área de exploração artesanal de Au em Serra Pelada -Amazônia, Brasil. Para tanto, foram coletados seis pontos amostrais no entorno do lago formado a partir da cava e um ponto em área de mata sem influência do garimpo. Os teores totais e disponíveis dos metais foram extraídos com água régia e solução 0,5 mol L-1 HCl respectivamente, seguidos das determinações através da espectrometria de emissão ótica com plasma de argônio acoplado indutivamente (ICP-OES). Todos os PTEs apresentaram teores totais acima dos valores de referência de qualidade para solos do estado do Pará. Os teores disponíveis de Cu, Pb e Zn foram superiores aos observados em solos de área de floresta do estado do Pará. Os teores de Cu total estão acima do valor de prevenção definido pelo Conselho Nacional de Meio Ambiente. Em média houve enriquecimento de Mo (41,0) > Cu (3,5) > Pb (1,4), o que indica que as áreas foram contaminadas por PTEs a partir das atividades antrópicas.

Evaluación de la concentración de mercurio en arroz (Oryza sativa) crudo y cocido procedente del municipio de San Marcos- Sucre y zona aurífera del municipio de Ayapel - Córdoba / Evaluation of the concentration of mercury in rice (Oryza sativa) raw and cooked from the municipality of San Marcos - Sucre and township gold zone Ayapel - Cordoba

Introducción: Los metales se encuentran en todos los alimentos, siendo de mayor preocupación la presencia de metales tóxicos como el mercurio, debido a los efectos adversos que causa en la salud del hombre, lo que lo ha convertido en un grave problema de salud pública. Objetivo: Evaluar la concentración de mercurio en arroz (Oryza sativa) crudo y cocido procedente del municipio de San Marcos - Sucre y zona aurífera del municipio de Ayapel - Córdoba. Metodología: El presente estudio es de tipo exploratorio y experimental. La toma de muestras fue realizada en tiempo de recolección del arroz (septiembre) y se tomaron tres repeticiones de cada tipo o variedad de arroz (Fedearroz 2000 - LD 473). La cocción del alimento fue realizada en el laboratorio en condiciones similares a las utilizadas por habitantes de las comunidades donde fueron recolectadas las muestras. Para los análisis de relación estadística entre los tratamientos de cocción y la concentración de mercurio total en muestras, fue realizado un análisis de correlación simple. La determinación de diferencias estadísticamente significativas entre las muestras de arroz crudo y cocido fue realizada mediante un t-test y Anova. Resultados: Se presentaron concentraciones bajas de mercurio total y metilmercurio en las muestras de arroz crudo y cocido. Además, fue detectado que el proceso de cocción del alimento disminuye las concentraciones de HgT, en los diferentes tratamientos de tiempo de cocción. Conclusiones: Los habitantes de los municipios en estudio están expuestos a concentraciones mínimas de mercurio que podrían ser perjudiciales para su salud, debido a la alta ingesta de este cereal en la dieta de las comunidades.

Introduction: Metals are found in mostly all kind of food. Presence of toxic metals such as mercury are relevant for public health safety, due to the adverse effects it has on human health. Objective: To evaluate mercury concentrations in raw and cooked rice (Oryza sativa) from San Marcos municipality in Sucre and Ayapel gold zone in Córdoba. Methodology: The present study is exploratory and experimental. Sample collection was conducted in rice harvesting time (September) and three repetitions of each type or variety of rice were taken (Fedearroz 2000 - LD 473). Cooking of rice was made under laboratory standards similar to those used by residents of the communities where the samples were collected. For statistical analysis of the relationship between cooking treatment and the concentration of total mercury in samples, we carried out a simple correlation analysis. Determination of statistically significant differences, between samples of raw and cooked rice, was performed using a t-test and Anova. Results: Low concentrations of total mercury and methylmercury were presented in raw and cooked rice. Furthermore, it was found that food cooking processes decreases HgT concentrations. Conclusion: Inhabitants of the municipalities under study are exposed to minimal concentrations of mercury that could be harmful to their health due to high intake of this cereal in their communities' diet.

The health impact assessment of mercury on artisanal and small scale miners and revealed chronic mercury intoxicated patients / Монголын Анагаах Ухаан

INTRODUCTION:In connection with request and financial assistance of Swiss Development Agency ‘’Mercury exposureand health impact assessment study among small scale miners in mercury free technology, wasconducted by researchers of Toxicology division of NCPH.GOAL:To determine mercury exposure level in biological samples of local small scale miners from mercury freetechnology introduced area. To reveal chronic mercury intoxicated patients,MATERIALS AND METHODS:Totally 147 artisanal miners from 33 cooperatives for small scale mining from Bayan-Îvoo soum ofBayankhongor, Bornuur sum of Tuv, Bayangol, Mandal and Tunkhel sum of Selenge province areparticipated in this study and the study was performed by cross sectional study methods during April toDecember, 2014.Over all 147 participants were in the first part of study, 60.5% out of 147 (89 participants) were in secondparts, and another 35.4% (52 people) were participated to the third parts of study. The participants wereundergone in to toxicological, dermatological and neurological examinations and the WHO guidance formercury exposure determination was followed in this study.RESULTS:On the results of all testing we revealed that there were 2 cases of chronic mercury intoxicated patientsfrom each Bayangol Bornuur soum, 2 from Mandal soum, and 3 from Bayanovoo soum.Overall 7 patientswere diagnosed as chronic mercury intoxicated and it comprised 4.7%of (n=147) all involved participants.We have observed that average height of total medical examination number was (2.9) in Bornuur soum.It indicated that there will have higher number of patients would exist in Bornuur soum than others.Ourstudy result has shown that neurological symptoms like tremor and imbalance were more diagnosedamong participants from Mandal and Bayngol soums. It implies that the health of the small scale minersfrom this soum more affected and needed to be investigating further.CONCLUSIONS:Mercury is still being used among artisanal gold miners even thoughit is still illegal. Further medicalevaluation and assistance needed to be taken for newly diagnosed 7 patients.

Convergencia de los grupos armadosorganizados al margen de la ley en laminería aurífera aluvial en la subregióndel Bajo Cauca antioqueño / Convergence of illegal organized armed groups in alluvial goldmining at the Department of Antioquia’s Bajo Cauca subregion / A convergência dos grupos armados organizados à margem dalei na mineração aurífera aluvial na sub-região do Baixo Caucaem Antioquia (Colômbia)

Se tuvo como propósito describir la minería aurífera aluvialy la convergencia de los grupos armados organizados almargen de la ley en la subregión del Bajo Cauca antioqueño.Los resultados obtenidos se centran en identificar el marcoteórico, proponer un concepto y describir los rasgos característicosde esta actividad desde la perspectiva criminal. Loanterior se logró a partir de una aproximación conceptual yla representación fáctica de la información obtenida, a travésde la revisión teórica, la consulta bibliográfica y el trabajode campo, en el que se aplicaron diferentes técnicas de recolección,como la entrevista semiestructurada, el grupo focaly la observación no participante. El precedente para comenzarla indagación se centró en la ausencia de un concepto que delimitelos tipos de minería y la confusión que existe al colocar atodos los mineros ilegales, informales y criminales dentro unamisma categoría. Además, se busca suscitar una reflexión críticarespecto a los posibles riesgos y amenazas que genera laconvergencia de estos grupos en los tipos de minería, con elcontrol social y territorial, el poder, la coacción y la institucionalizaciónde actividades económicas criminales.

The purpose of this article was to describe alluvial goldmining and the convergence of the organized illegal armedgroups in the Department of Antioquia’s Bajo Caucasubregion. The results obtained are focused on identifyingthe theoretical framework, suggesting a concept, and describingthe characteristic features of this activity from thecriminal perspective. This was achieved on the basis of aconceptual approach and the factual representation ofthe information obtained through theoretical review, bibliographicconsultation and field work in which differentgathering techniques such as semistructured interviews, focusgroups and non-participant observation were applied.The precedent for starting the inquiry was focused on theabsence of a concept serving to delimit mining types andthe confusion created by placing all illegal miners, either informalor criminal, within the same category. In addition, itis intended to raise a critical reflection with respect to thepotential risks and threats that the convergence of thesegroups in these types of mining can create with social andterritorial control, power and coercive power, and the institutionalizationof criminal economic activities.

O propósito era descrever a mineração aurífera aluvial e aconvergência dos grupos armados organizados à margem dalei na sub-região do Baixo Cauca em Antioquia (Colômbia).Os resultados obtidos focam-se em identificar o marco teórico,propor um conceito e descrever as características destaatividade desde a perspetiva criminal. Esses resultados foramobtidos de uma aproximação conceptual e a representaçãofática das informações obtidas, através da revisão teórica, aconsulta bibliográfica e o trabalho de campo. Utilizaram-setécnicas diferentes de colheita, como a entrevista semiestruturada,o grupo focal e a observação não participante.O precedente para começar a investigação foi centrado naausência de um conceito que limitasse os tipos de mineraçãoe da confusão que existe ao colocar a todos o mineiros ilegais,informais e criminosos dentro de uma mesma categoria.Além, procura-se provocar uma reflexão crítica com respeitoaos riscos e às ameaças possíveis que a convergência destesgrupos gera nos tipos de minaração, com o controle social eterritorial, o poder, do coação e a institucionalização de atividadeseconômicas criminosas.

Mercury and gold mining in Colombia: a failed state / Colombia minera y uso de mercurio: un estado fallido

Identificar y analizar las causas y consecuencias que están generando altos niveles de consumo de mercurio en la actividad aurífera es una prioridad internacional. Con el fin de hacer un diagnóstico de la actividad minera aurífera y del uso excesivo de mercurio en Colombia se usaron seis fuentes de información (entrevistas semi-estructuradas y censo minero 2011), nueve variables dependientes y 21 independientes. El 87% de las minas auríferas del país no tenían título minero y sólo el 3% contaba con licencia ambiental. Se evidenció que los mineros prefieren el uso del mercurio para el beneficio del oro por ser un método fácil, rápido y económico. Las causas de los altos niveles de consumo de mercurio en la actividad aurífera identificados fueron: la alta ilegalidad minera y ambiental, el fracaso de los programas de formalización y la falta de control sobre las importaciones del insumo. Los estudios evidenciaron concentraciones de mercurio por encima de los límites permitidos. Ante esta situación el Gobierno se ha inclinado por una política de persecución a la actividad en lugar de fomentar su formalización...

Identifying and analyzing the causes and consequences that generate the high consumption of mercury in gold mining activities is an international priority. In Colombia, eighty-seven percent of the country's gold mines have no mining title and only 3% possess environmental licenses. High mining and environmental lawlessness, the failures of formalization programs and the inadequacy of importation controls on the supply are the cause of the high consumption of mercury in Colombian mining. To diagnose the country's gold mining activities and the excessive use of mercury in them, we used six information sources (semi-structured interviews, 2011 Census on Mining Activities), nine dependent and 21 independent variables. The study evidenced the miners' partiality in favor of the use of mercury in the procurement of gold; the process is easy, quick and inexpensive. Mercury concentrations were found to be above tolerable levels. In response, government has opted for a policy of persecution of the activity rather than the promotion of their formalization...

Identificar e analisar as causas e consequências que estão gerando altos níveis de consumo de mercúrio na atividade aurífera é uma prioridade internacional. 87% das minas auríferas do país não têm título mineiro e somente 3% conta com licença ambiental. Alta ilegalidade mineira e ambiental, o fracasso dos programas de formalização e falta de controlo sobre as importações de consumo são as causas dos altos níveis de consumo de mercúrio na atividade aurífera. Para diagnosticar esta atividade e o uso excessivo de mercúrio na Colômbia, usaram-se seis fontes de informação (entrevistas semi-estruturadas, censo mineiro 2011), nove variáveis dependentes e 21 independentes. Evidenciou-se que os mineiros preferem o uso de mercúrio para o benefício do ouro porque é um método fácil, rápido e económico. Os estudos evidenciam concentrações de mercúrio acima dos limites permitidos. Ante esta situação o Governo inclinou-se para uma política de perseguição à atividade em lugar de fomentar a sua formalização...

Health Risks to Children and Adults Residing in Riverine Environments where Surficial Sediments Contain Metals Generated by Active Gold Mining in Ghana

The purpose of this study was to investigate the current status of metal pollution in the sediment from rivers, lakes, and streams in active gold mining districts in Ghana. Two hundred and fifty surface sediment samples from 99 locations were collected and analyzed for concentrations of As, Hg, Cr, Co, Cu, Fe, Zn, Pb, Cd, Ni, and Mn using inductively coupled plasma-mass spectroscopy (ICP-MS). Metal concentrations were then used to assess the human health risks to resident children and adults in central tendency exposure (CTE) and reasonable maximum exposure (RME) scenarios. The concentrations of Pb, Cd, and As were almost twice the threshold values established by the Hong Kong Interim Sediment Quality Guidelines (ISQG). Hg, Cu, and Cr concentrations in sediment were 14, 20, and 26 times higher than the Canadian Freshwater Sediment Guidelines for these elements. Also, the concentrations of Pb, Cu, Cr, and Hg were 3, 11, 12, and 16 times more than the Australian and New Zealand Environment and Conservation Council (ANZECC) sediment guideline values. The results of the human health risk assessment indicate that for ingestion of sediment under the central tendency exposure (CTE) scenario, the cancer risks for child and adult residents from exposure to As were 4.18 x 10(-6) and 1.84 x 10(-7), respectively. This suggests that up to 4 children out of one million equally exposed children would contract cancer if exposed continuously to As over 70 years (the assumed lifetime). The hazard index for child residents following exposure to Cr(VI) in the RME scenario was 4.2. This is greater than the United States Environmental Protection Agency (USEPA) threshold of 1, indicating that adverse health effects to children from exposure to Cr(VI) are possible. This study demonstrates the urgent need to control industrial emissions and the severe heavy metal pollution in gold mining environments.

Estudio de métodos químicos de remoción de cianuro presente en residuos de cianuración provenientes del proceso de extracción de oro de veta en el departamento de Nariño / Study f chemicall methods for cyanide removal from cyaidation waste ccoming from the gold vein extraction process in the department of narñoo

Esta investigación se centró en la neutralización a nivel de laboratorio de residuos cianurados provenientes de la mina Nueva Esparta ubicada en el municipio de los Andes-Sotomayor (Nariño), con tres neutralizantes de tipo comercial en distintas relaciones en peso (gramos de neutralizante/gramos de CN- libre/total a neutralizar): peróxido de hidrógeno H2O2 2/1, 5/1 y 8/1, hipoclorito de sodio NaOCl 7/1, 12/1 y 17/1 y sulfato ferroso FeSO4 6/1, 12/1 y 18/1. Las arenas residuales se trataron así: lavado con agua, neutralización del agua de lavado y recirculación de la misma para un nuevo lavado; esto con el objeto de minimizar la cantidad de agua empleada. Después del análisis estadístico y teniendo en cuenta consideraciones técnicas, económicas y ambientales, se encontró que los mejores tratamientos para la remoción de cianuro libre y total son respectivamente las relaciones 2/1 y 5/1 del H2O2. Se realizó una caracterización fisicoquímica de la fuente de agua afectada por la actividad de la mina en estudio, de la solución pobre de cianuro y soluciones lixiviadas en laboratorio. En la evaluación de los metales Fe, Cu, Ni, Zn, Mn y Pb se observó que luego de la neutralización con H2O2, los metales analizados disminuyeron su concentración; con NaOCl se presentó un incremento en la mayoría, con una remoción mínima de plomo y manganeso. Con FeSO4, se obtuvo remoción para la mayoría, pero plomo y manganeso se incrementaron.

This research focused on laboratory-scale neutralization of cyanide wastes from the Nueva Esparta mine in the municipality of Los Andes, Sotomayor (Nariño) with three commercial type neutralizers in different weight ratios (neutralizer grams / CN-free/total to be neutralized): hydrogen peroxide H2O2 2/1, 5/1 and 8/1, sodium hypochlorite NaOCl 7/1, 12/1 and 17/1 and ferrous sulfate FeSO4 6/1, 12/1 and 18/1. Residual sands were treated as follows: washing with water, neutralization of the washing water and circulation of the same water for a new washing process, this with the purpose of minimizing the quantity of water used. After the statistic analysis and taking into account technical, economical and environmental considerations, it was found that the best treatments for removing free and total cyanide are respectively the relations 2/1 and5/1 from H2O2. A physical-chemical characterization of the water source affected by the activity on the poor cyanide solution and solutions lixiviated in the laboratory of the mine under study was performed. In the evaluation of the metals Fe, Cu, Ni, Zn, Mn and Pbit was observed that after the neutralization with con H2O2, the analyzed metals diminished their concentration. There was an increase in the majority With NaOCl woth a minimum removal of lead and manganese. With FeSO4 there was removal for the majority but lead and manganese increased.

Contaminação mercurial em peixes do rio madeira: resultados e recomendações para consumo humano

Samples of eleven fish species were collected during September and October of 1991 in the gold mining area of Cachoeira de Teotônio and in the control area Guajará-Mirim, along the Madeira River, (Rondônia, Brazil) and anaiized for total mercury by cold vapor atomic absorption spectrofotometry. Almost all fish predators from the gold mining area had mercury concentrations above the maximal level of 0.5 ug.g"1, permitted for human consumption by Brazilian Secretary of Health and the World Health Organization and much greater than those found in predatory fish species in the control area were all below this critical value (0.5 pg.g'X demonstrating the influence of anthropogenic contamination in the gold mining area. In both areas, non-predators fish species had lower mercury concentrations than predators fish species, indicating the effects of biomagnification of mercury in the food chain. Safety limits for fish consumption by the human populations in this gold mining area were estabilished considering the mercury levels encontred in fish and the critical intake rate associated with the signs of mercury poisoning. Pacu, could be consumed without restrictions, matrinchã, curimatã, mandi and tucunaré, could be consumed with moderation and large predatory fish species (mostly Siluriformes), could be consumed only sporadically. Some factors that could influence mercury contaminations in "ribeirinhos" are discussed.

A concentração de mercúrio total foi determinada em onze espécies de peixes coletados de setembro a outubro de 1991, na área de garimpo de ouro da Cachoeira de Tcotônio e da área considerada controle em Guajará-Mirim, ambas no rio Madeira, Estado de Rondônia. Utilizou-se, para a análise, a técnica de espectrofotometria de absorção atômica com gerador de vapor frio de Hg. Quase todos os peixes predadores da área de garimpo tiveram concentrações de mercúrio acima do nível critico de 0,5 pg.g"1 permitido para consumo humano pelo Ministério da Saúde do Brasil e Organização Mundial de Saúde, sendo bem maiores que as concentrações de mercúrio nas espécies predadoras da área controle, evidenciando a influência do garimpo de ouro na contaminação dos peixes por mercúrio. As espécies não-predadoras tiveram concentrações de mercúrio abaixo daquelas das espécies predadoras para as duas áreas, indicando o efeito da biomagnificação do mercúrio na cadeia alimentar. Procurou-se estabelecer limites para o consumo de peixes pelas populações humanas da área de garimpo estudada, calculando-se a taxa de ingestão necessária para se desenvolver os primeiros sintomas de contaminação mercurial. Concluiu-se que espécies como o pacu podem ser consumidas sem restrição, já os peixes como matrinchã, curimatã, mandi e tucunaré, deveriam ser consumidos com moderação e que a maioria dos peixes predadores (em geral Siluriformes), deveriam ser consumidos apenas esporadicamente. Discutem-se alguns fatores que poderiam estar interagindo no processo de contaminação por mercúrio dos ribeirinhos dessa área de garimpo.