Illegal Mining and Mercury in the Amazon

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The  Amazon Sustainable Landscapes Program  (ASL) is a regional initiative led by the World Bank and funded by the  Global Environment Facility  (GEF), which aims to protect globally important biodiversity and implement policies to promote sustainability, land use and land cover restoration in the Amazon region. In its first phase, this common objective is achieved through the implementation of national projects in Brazil, Colombia and Peru, and a regional project that promotes coordination and capacity building and the exchange of experiences among projects, agencies involved with the ASL and entities in charge of similar regional efforts.

This StoryMap is the result of work commissioned by the ASL to the  Foundation for Conservation and Sustainable Development  (FCDS) with the objective of strengthening regional collaboration to counteract, remediate, restore and respond to the impacts of gold mining and mercury pollution. This work analyzed the general panorama of the dynamics of illegal mining in border territories (Brazil, Colombia and Peru), compiling documented information, filling existing information gaps, increasing understanding of the dynamics and impacts, and providing recommendations for managing these impacts on ecosystems and the public health of communities, based on coordinated actions in the Amazon region. 

The work placed particular emphasis on the Yaguas-Cotuhé and Puré River territories as pilot sites of high biological and cultural diversity, which made it possible to dimension the complexity of the problem in subregional scenarios. The analysis considered variables such as the legal status of the territory, the existence of conservation areas and indigenous territories and their contribution to the protection of natural and socio-cultural values, as well as geographical, biophysical and socioeconomic elements.

The analysis considers the problem of illegal mining in the pilot sites, based on the collection of secondary sources, their analysis and validation by partners, mainly from the Amazon Regional Alliance for the Reduction of the Impacts of Gold Mining (ARAIMO).  ARAIMO, integrated by civil society organizations and institutions from Colombia, Peru and Brazil [ Frankfurt Zoological Society  - FZS Colombia and Peru,  GAIA Colombia Foundation ,  WWF Colombia ,  National Natural Parks of Colombia ,  Oswaldo Cruz Institute  - FIOCRUZ of Brazil,  Center for Amazonian Scientific Innovation  - CINCIA of Peru,  Amazon Conservation Team  - ACT Colombia,  University of Cartagena , Colombia and FCDS Peru and Colombia], aims to join efforts and thematic and territorial expertise to provide comprehensive readings on the problem of gold mining and the use of mercury, which are useful for decision making in the Amazon context, particularly in border scenarios. This document presents the impacts on health, the environment and hydrobiological resources caused by gold mining activities in sensitive areas. 

The validation of the information presented here has been carried out in multiple national and regional events, with the participation of governmental and non-governmental organizations, indigenous communities, academia and researchers from Brazil, Colombia and Peru, who have also contributed to the compilation of information and stimulated dialogue and exchange of experiences on the dynamics of legal and illegal mining in a complex scenario that combines various social, political and economic decisions in the region.

This StoryMap was prepared by FCDS with the collaboration of ARAIMO's partner organizations, with the special participation of the technical teams in Colombia of the Frankfurt Zoological Society (FZS) and Amazon Conservation Team (ACT). 

The Amazon is currently under multiple anthropogenic pressures, including gold mining, which have caused considerable deforestation and land degradation (Ellwanger et al., 2020). In addition to the impact on deforestation, the use of mercury in artisanal and illegal gold mining has generated that this highly polluting substance is present in the food chains, in its most toxic form (methylmercury), affecting human populations through the consumption of contaminated fish (Crespo-López et al., 2021). 

The predominant mining activity in the Amazon is alluvial mining, defined by the  Colombian National Mining Agency  - ANM (2003) as "mining activities and operations carried out on riverbanks or riverbeds".  The  Peruvian Ministry of Environment  - MINAM adds that this mining is also carried out in drylands as long as they are surface deposits (not coming from the subsoil) (MINAM, 2016). Alluvial mining can be carried out through different practices such as open-pit or over rivers using boats. In both cases it is usual to use inputs such as mercury and fuel (diesel or gasoline), to separate the gold and the operation of the extraction pumps (Valencia, 2015). The use of backhoes for open-pit mining activities results in deforestation, soil degradation, alteration of the quality and detour or loss of natural water courses, among other negative impacts ( United Nations Office on Drugs and Crime  - UNODC, 2021). For mining on rivers, the use of dredges or rafts in operations located directly in watercourses generates the alteration of suspended sediments and with this, the natural dynamics of the trophic chains.

The dynamics of illegal mining presented at the general level and in the pilot sites in transboundary territories, results from the collection of information on the presence of illegal gold mining in these border scenarios Brazil, Colombia and Peru. This compilation took into account secondary information sources of various types (cartographic, interviews, documents, among others), own construction from the identification of rafts using satellite images for the period 2018-2022.  With the above, it was possible to identify the transformation processes of the Amazonian rivers present in the study area and the areas where there is evidence of the presence of mining rafts or dredges in the river routes (Map 1 illustrates the routes along which the dynamics of illegal mining flow in the triple border Brazil, Colombia and Peru). The rivers with presence of illegal mining were the Nanay (Peru), Pintuyacu (Peru), Chambira (Peru), Cotuhé (Peru-Colombia), Putumayo-Icá (Peru-Colombia-Brazil), Caquetá-Japurá (Colombia-Brazil), Puré-Purué (Colombia-Brazil) and Purité-Purete (Colombia-Brazil).

The pilot sites under study, which share the triple border of Brazil, Colombia and Peru, are located in a strategic area due to the diversity of their ecosystems and the presence of indigenous communities. However, the region suffers from a high level of illegal mining activity, with constant presence of rafts and dredges.  To analyze the environmental and socio-cultural impacts of illegal gold mining and mercury contamination in the pilot sites, use was made of the  Illegal Gold Mining Impact Calculator  tool, designed by the Conservation Strategy Fund (CSF) initially for Brazil on behalf of the Federal Public Ministry and later adapted to Colombia and Peru with the support of the ASL regional project.

For the elaboration of this product, information on the problem of illegal mining in the pilot sites was compiled, mainly from secondary information sources, scientific articles, interviews and presentations of regional Amazonian meetings and exchanges of related information among members of ARAIMO. With this compilation, statistical and spatial analyses were made for a better understanding of the impacts generated by this activity. 

The main findings of the compilation and analysis of the information provided and validated by partners, mainly from ARAIMO, focused on those prioritized tripartite border areas where mining impacts have been documented and that facilitate the dimensioning of the complexity of the problem and the necessary coordinated actions of the three countries. The document presents the impacts on health, the environment and hydrobiological resources caused by illegal gold mining activities in sensitive areas of the study area.

Initially, it is essential to define what is legal mining, informal mining and illegal mining. Legal mining employs more ingenious exploitation techniques, with greater industrial safety and skilled labor (Betancur-Corredor et al., 2018), additionally it is covered by law and is developed in areas suitable for this activity. Not all legal mining uses mercury and, some mining practices, in response to regulations and conventions (e.g. Minamata Convention), have gradually reduced the use of mercury and transition to clean technologies. Informal mining is composed of those mining operators that are not legal, but have initiated a formalization process, and do not operate in prohibited areas or use machinery that does not correspond to their category (MINAM, 2013). Illegal mining is that which does not comply with the administrative, technical, social and environmental requirements of the law, or which is carried out in areas where it is prohibited (MINAM, 2013).

These two forms of mining differ from legal mining, since they do not have a mining title to carry out their extraction activity. A mining title is a permit that grants the right to explore and exploit the soil and subsoil to all natural and legal persons and community miners, as long as they comply with all the technical and legal requirements of the competent mining authority.

Additionally, the weak presence of government authorities with powers in the region prevents them from exercising effective control over the territory, even in protected natural areas affected by informal and illegal mining activity (Correa, 2015). This, added to the difficulty in controlling the use of polluting elements such as mercury, increasing the productivity of the business even at the cost of environmental degradation (WWF & GAIA Amazonas, 2019).

The analysis of the triple frontier clearly shows 6 transboundary rivers (see Table 1) that require the efforts of the three governments to control the impact of illegal gold mining on ecosystems and on the public health of indigenous and non-indigenous populations.

To better understand the impacts caused by the use of mercury in illegal mining, studies that have measured the concentrations of this metal in fish and humans were compiled. For this pilot site, fish studies conducted in Puerto Nariño (Salinas et al., 2014; Alcalá-Orozco et al., 2020), in the CIMTAR association (PNN et al., 2018) and in Tarapacá (Núñez-Avellaneda et al., 2014) were incorporated. Human studies considered in the analysis were conducted in Puerto Nariño (Alcalá-Orozco et al., 2020) and in the CIMTAR Association (PNN et al., 2018). 

Likewise, to identify the impacts on the ecosystems, we used the information collected from overflights and daily satellite images at a detailed scale, which have become a fundamental tool for detecting pressures on Amazonian ecosystems in areas that are difficult to access. The detection of the effects of the presence of dredges for the illegal extraction of alluvial gold was achieved through the images, with subsequent verification with overflights. Currently, the Purité River has undergone analysis using information collected from two overflights, as well as a series of 3-meter and 5-meter precision images from the supplier, Planet Scope Lab. Based on these inputs, the impacts to the ecosystems of this pilot site are presented.

Despite the limitations of access to this territory, there are studies that have measured mercury levels in fish and humans. For this pilot site, studies conducted in fish in the Puré River (PNN et al., 2018) and in the PANI Association (Bora Miraña Association of Traditional Indigenous Authorities) (PNN et al., 2018) were considered. The human studies that were contemplated were conducted only in communities of the PANI Association (PNN et al., 2018). 

In addition, information from overflights and high-resolution (50 cm) satellite images, courtesy of Maxar Technologies Inc. 

In the particular case of the pilot sites, mercury enters the aquatic ecosystems from the gold mining activity carried out by settlers and foreigners who use barges equipped with suction systems to extract the sediment from the riverbeds. The sediment is then washed and mercury is added to amalgamate the gold particles. The residual mercury is dumped into the water where it is transformed into methylmercury, a compound that can be absorbed more easily by living organisms such as microalgae, which transfer it to small invertebrates and fish that consume it and are incorporated into the trophic chain up to their ultimate consumer, people.

This involves the rest of the ecosystem's trophic network, which also includes higher order fish, birds, mammals such as otters, and people. The latter becomes, in most cases, the final destination of this toxicant, due to the ingestion of contaminated fish and, to a lesser extent, the consumption of water contaminated with this element. Fish is the main source of protein for multiple indigenous and non-indigenous populations within the pilot sites. According to literature in the Colombian Amazon, riverine communities may consume between 100 - 500 grams of fish per day (Agudelo, 2015).

Inhalation of mercury vapors is another route of contamination, less usual given that generally surface waters have low concentrations of this metal. This type of exposure is limited to people who are in charge of processing the gold after extraction (PNN, 2018).

Factors that determine the occurrence of adverse effects and the severity of the effects on health include: the chemical form of mercury, dose, age of the person exposed (with the fetal stage being the most vulnerable), duration of exposure, route of exposure (inhalation, ingestion or dermal contact), and dietary patterns of consumption of fish and shellfish (WHO, 2008 in MINAM 2020).

The main systems affected by the toxicity of mercury and its compounds are the nervous, circulatory, respiratory and reproductive systems (Figure 5). In general, systems with developing organs -such as the fetal nervous system- are the most sensitive to the toxic effects of mercury. Other systems that may be affected are the respiratory, gastrointestinal, hematological, immune and reproductive systems (WHO, 2008 in MINAM 2020), as detailed in Video 1.

It is important to reiterate that methylmercury is a toxic and persistent pollutant that bioaccumulates throughout the trophic chain. The older the organism and the higher the level in the food chain, the higher the concentration of methylmercury (WHO, 2008 in MINAM 2020).

There are two general types of susceptible subpopulations: those that are more sensitive to the effects of mercury and those that are exposed to higher levels of mercury. A sensitive population is a group that may experience more severe adverse effects at comparable exposure levels or adverse effects at lower exposure levels than the general population. For mercury, the most sensitive subpopulations are developing organisms, especially the fetus. Other subpopulations may be exposed to higher levels of methylmercury due to consumption of fish and shellfish and may have a higher risk of mercury toxicity (WHO, 2008 in MINAM 2020). 

Once the data were spatialized, an analysis was made by sampled communities to observe which places are most affected by this problem. Graph 8 shows the mercury concentrations in hair by sampling location. The results found are consistent with the high concentrations of mercury in fish, where all records within the area of analysis indicated coincidence with high and very high concentrations of mercury in humans.

When assessing the impact of heavy metal concentrations in different matrices, different reference values were taken into account, such as regulatory limits, human biomonitoring values or HMB, among others. There are two different HMB values: HMB I, which refers to the concentration below which there is no adverse health risk, and HMB II, which indicates the concentration above which the risk of an adverse health effect increases (Umwelt Bundesamt, 2015). These reference values currently exist for mercury in urine and blood, however, they are not available for mercury in hair. However, a study by Drasch et al. (2001) estimated an analogous HBM II for mercury in hair with a value of 5ppm, considering the blood-hair mercury ratio and samplings where adverse effects were evident from this concentration (Davidson et al., 1998). Using this estimate, all the communities sampled within the subregional analysis polygon are above the analogous HBM II (Graph 8), with some communities showing almost four times its value (e.g. Las Palmas with 19.7 ppm).

Likewise, blood tests taken in Puerto Nariño showed an average mercury concentration of 13.7 µg/l, a value that is between the HBM I and HBM II for mercury in blood. In such cases, a larger number of samples would allow confirming the threat and urgently recommend minimizing the exposure of these populations (Umwelt Bundesamt, 2015). 

Based on the above, it becomes evident that mercury contamination within the subregional analysis area is critical and requires immediate action to reduce the exposure of communities to this contaminant.

The Purité River is currently the most affected by illegal mining of all the rivers in the pilot site. Illegal mining on this river, as in many rivers in the Amazon, has altered the surface and underlying forest strata. In addition, the impacts of mining exploration and development have altered natural watercourses and flows, as well as reproduction sites for species native to these ecosystems. The noise generated by the installation and operation of dredges has altered the natural conditions of fauna mobility, and the use of diesel and gasoline-powered equipment has caused waste to flow directly through the waterways, impacting the dynamics of the associated aquatic and terrestrial ecosystems, including soil, vegetation, rivers, lagoons, and phreatic deposits.

Baseline studies conducted in the Napo River (Loreto, Peru) by Rengifo & Reyes in 2012, conclude that mercury values between 0.023 and 0.027 mg/L were found in the water, results that exceed the national standards established by MINAM (0.0001mg/L of Hg).  These figures exceed the value of 0.00002 mg/L of Hg that was reported by the Peruvian General Directorate of Environmental Health (DIGESA) in October 2003 and November 2010, in samples taken from the 4 stations sampled in the Napo River. In the same study by Rengifo & Reyes in 2012, it was found that, in sediments, 93.75% of the samples exceeded 1.0 mg/kg of mercury, thus confirming the significant presence of mercury at levels that exceed national Environmental Quality standards.

These modifications destabilize the river's drainage pattern, generating an erosive process that can occur at different points. This process can last for several years and can in turn increase the impacts on riparian communities and ecosystems.

According to Sentinel-2 satellite alerts between January 01, 2019 and November 24, 2022, 77.4 ha of the Purité or Puretê riverbank forests in Brazil have been affected (Map 15), of which 56 ha (73%) have been deforested by 2022.

As in the Purité River, mining dredges with high extraction capacity operate on the Puré River, highly technical double-decker vessels that destroy vegetation and soil, making ecosystem recovery unfeasible in the short term due to deforestation and in the medium term due to the use of mercury in their operations. 

As can be seen in the PLANET satellite images between 2019 and 2023, the impacts associated with mining in the Puré River are considerably greater compared to those of the Purité River.

According to Sentinel-2 satellite alerts between January 1, 2019 and September 11, 2022, 620 ha of the Puré or Purué riverbank forests in Brazil have been affected (Map 16), of which 333 ha (53%) were deforested in 2022 (the total volume removed from the forests has not yet been estimated). 

Based on the main elements of the analysis carried out in border territorial contexts and discussions with representatives of governmental and non-governmental organizations, indigenous communities, academics and researchers from Brazil, Colombia and Peru, roadmap proposals were developed to collaboratively address three main areas: 1. restoration and recovery of degraded ecosystems; 2. support for vulnerable communities affected by mercury contamination; 3. capacity building and harmonization of policies and protocols for the application of environmental legislation.

8.1.1   Knowledge Management

• Generate a regional inventory of mercury used in illegal mining, in order to identify critical areas for restoration and recovery that are being affected by this heavy metal.

• Design a cross-border sampling protocol to collect field information on physical aspects, measurement of hydrological and physicochemical variables, defining laboratory aspects and biological matrices. This in order to elaborate a baseline comparable between countries, which will allow identifying sites and prioritizing restoration and recovery actions in areas affected by mining.

• To exchange experiences between countries to strengthen local governments and coordinate actions with the purpose of harmonizing and building suitable methodologies for Amazonian landscapes in processes of restoration and recovery of areas affected by the use of mercury, following the guidelines of the Minamata Convention on the management of contaminated sites.

• Generate a multi-stakeholder network -institutional, civil society, NGOs, of projects implemented and projects to be implemented-, which will allow to demonstrate the progress of the countries in the restoration and recovery of areas affected by the use of mercury in illegal mining, framed in Articles 17 (Information exchange) and 18 (Information, public awareness and training) of the Minamata Convention.

• Advance a restoration and recovery process in a prioritized sector in the pilot sites.

• Monitor and follow up on restoration and recovery actions in a prioritized sector in the pilot sites.

• Promote actions through the Ministries of Foreign Affairs of the countries, with the Binational Cabinets for the implementation of a transboundary monitoring system of the impacts of illegal mining, promoting expeditions to have greater knowledge about the state of ecosystems and biodiversity, which contributes to the prioritization of actions in restoration and recovery in the pilot sites affected by mercury contamination.

• Identify sources of funding for restoration and recovery actions at pilot sites.

8.1.2   Capacity Building

• Strengthening of regional laboratories with a view to accreditation and intercalibration, strengthening of researchers and social actors in the collection, management and analysis of mercury in different environmental matrices, in order to have information to guide efforts to restore and recover affected sites and reduce contamination.

• Support the implementation of pilot cases in processes of transition to mercury-free technologies.

8.2.1 Knowledge Management

• Propose protocols for epidemiological studies and definition of health variables associated with the environment, taking into account sociocultural impacts. This protocol should be adapted to an Amazonian context, in order to benefit all types of vulnerable populations, taking into account their different limitations (e.g. language, culture, among others).

• Conduct a characterization of the toxicological status of fish of importance for human consumption and of cultural interest, with the participation of local indigenous and non-indigenous stakeholders.

• Establish a standard for mercury content in fish for human consumption from an Amazonian context. This in order to use reference values more appropriate to the fish consumption of Amazonian populations, since the WHO international standard (0.5 ppm) was designed for an adult person with a consumption of 200 grams of fish per week. Therefore, as the Amazonian communities consume more than 200 grams of fish per week, this makes the permissible limit of mercury in their diet necessarily lower, since as exposure increases through intake, the dose should decrease.

• Conduct an epidemiological study in the indigenous and non-indigenous communities that inhabit the pilot sites and follow-up on existing studies.

• Conduct studies of ecosystem services as a determinant of health at the pilot sites, with a focus on mercury contamination in biotic and abiotic matrices (e.g., hydrobiological resources and water quality, etc.)

• Propose a standardized and integrated monitoring system between Brazil, Colombia and Peru on the health effects of mercury poisoning, including citizen participation.

• Generate information associated with the problems caused by the health effects on Amazonian populations due to the use of mercury in illegal mining and communicate it effectively to give greater visibility to the impacts and risks, generating greater understanding by the general public and indigenous communities about the different implications of this activity.

8.2.2 Capacity Building

• Strengthen local health systems in the countries of Brazil, Colombia and Peru in the treatment and diagnosis of mercury poisoning.

• Conduct educational campaigns in order to implement a culture of prevention of mercury exposure through capacity building of the communities.

• Implement scholarship programs for the indigenous population for training in contaminant monitoring.

• Generate a capacity-building space for indigenous people to carry out epidemiological studies (exchange of experiences) with materials that take into account the context and language.

• Articulate a space for the exchange of experiences between indigenous and non-indigenous communities from Brazil, Colombia and Peru, on the impact of gold mining in their territories (focused on the health of the territories).

• Conduct an exchange of knowledge between institutions of Amazonian countries on shortcomings, success stories and opportunities for cooperation to strengthen Amazonian health systems on mercury issues.

8.3.1   Knowledge Management

• Generate a tool to consult spatial information related to mercury and illegal mining, analyze it and produce technical inputs that contribute to law enforcement in national and border scenarios, facilitating harmonization with other existing platforms.

• Establish an inter-institutional body to define an interoperability protocol between the fiscal control entities of the three countries, in order to build judicial cases related to illegal mining in cross-border scenarios. In this way, it will be possible to share valuable information on criminal and investigative processes, which can facilitate law enforcement.

• Stimulate cooperation on law enforcement between the Prosecutor's Offices of the three countries by promoting a training process that allows for the definition of the technical/scientific elements required for criminal proceedings and better decision making.

• Strengthen control actions on the entry and exit of vessels in border areas through checkpoints to reduce the illegal trade of mercury, gold and inputs, in compliance with the Minamata Convention by the Amazonian countries.

• Use the  Artisanal Gold Mining Impact Calculator  developed by CSF as a tool to seek to apply the law in accordance with the environmental damages associated with this activity.

• Support law enforcement processes with the participation of civil society organizations through capacity building, technical inputs and support for the generation of information.

8.3.2   Capacity Building

• Implement an early warning system through overflights and remote sensing, coordination of social and institutional actors and field trips to monitor illegal mining activity, mercury contamination and associated environmental liabilities, which will contribute to decision-making at the watershed level.

• Structure and develop a training process for the different control entities on the dynamics of illegal mining in border scenarios, on geographic information systems tools to identify illegal mining activities and on the socio-cultural context of the Amazon.

8.3.3   Implementation of the Minamata Convention

• Harmonize cross-border policies on actions against illegal mining, based on the Minamata Convention, through national action plans for mercury reduction (analyzing conditions in shared watersheds and transboundary Amazonian rivers). Such harmonization should include a cross-review of each country's standards on the main issues (environmental quality, monitoring systems and bans). The above, through joint management in platforms being implemented for the Putumayo basin for the joint implementation of the Minamata Convention.

• Design and implement comprehensive prevention and health care plans with an intercultural approach on the effects of mercury exposure, framed in Articles 16 (health-related aspects) and 18 (public information, awareness and education) of the Minamata Convention.

• Generate and implement public policy advocacy strategies (Brazil, Colombia and Peru) for the reduction and elimination of mercury, other metals and pollutants in artisanal and small-scale mining.

Phase 1: Francisco Camacho | Territorial Analysis Professional (FCDS) Víctor Moreno | Mining Impacts Coordinator (FCDS Colombia - Peru) Wayu Matapí | Expert in Intercultural Relations (FCDS) Adriana Vásquez | Communications Coordinator (FCDS) Michelle Morales | Journalist (FCDS) Phase 2: Francisco Camacho | Territorial Analysis Professional (FCDS) Víctor Moreno | Mining Impacts Coordinator (FCDS Colombia - Peru) Wayu Matapí | Expert in Intercultural Relations (FCDS)   João Barroso | Diseñador (FCDS) Andrea Buitrago | Director, FCDS Perú In collaboration with: Germán Mejía | Protection & GIS Professional (ACT Colombia) Ricardo Erazo | Geographic Information Systems Leader (FZS Colombia)