The Fate of Mercury Used in Artisanal and Small-Scale Gold Mining (ASGM) in Amazonian Ecosystems
Primarily due to its prevalent use in gold extraction, mercury (Hg) has emerged as a significant health issue in many regions of the developing world, particularly within the Amazon. Mercury use and release is associated with artisanal and small-scale gold mining (ASGM), conducted by individuals or small groups of miners operating mostly informally with little or no regulation.
This type of mining uses rudimentary methods including mercury amalgamation, and thus impacts local, regional and global environments through contamination and land-use change. Globally, ASGM is considered the largest source of mercury pollution to the atmosphere and to water. When mercury enters terrestrial and aquatic ecosystems, it can be converted to methylmercury that bioaccumulates in aquatic food webs.
Unfortunately, many gaps still exist in our understanding of the cycling of mercury through Amazonian ecosystems, particularly in areas associated with ASGM given the often illegal and transient nature of the situation.
This IGCP project team will integrate and generate scientific knowledge to better understand how mercury pollution from ASGM is transported, transformed, bioaccumulated and sequestered in Amazonian ecosystems.
The results will be shared with local communities and government to help facilitate the implementation of strategies and public policies aimed at minimising the damage caused by mercury.
Key information
Duration
2020-2024
IGCP Theme
Earth Resources
Project Leader
Department of Earth Sciences, University of Toronto, Canada
Highlights
HgAmazonia meeting
The IGCP 696 team met for the first time in Madre de Dios, Peru, one of the largest regions of artisanal and small-scale gold mining (ASGM) in the Amazon, in November 2022. The event had 35 participants from seven countries, and over 70% of these were from Latin America. Interactive working sessions created a synthesis of targeted, achievable research priorities that will lead to new collaborations between research groups. We also developed messages to different audiences (miners, indigenous communities, policy makers, etc.), and identified major obstacles to successful action on reducing mercury use in ASGM. Our final activity was to make commitments to achieve our research and communication priorities which included:
- capitalising on strategic opportunities for new funding
- improving linkages with policy makers for better decision-making
- increasing collaborations
- providing training and analyses in various laboratories
- creating shared and accessible databases
Participants also spent one day in the field, visiting a post-ASGM mining site in the La Pampa Gold Mining Zone, an area where illegal gold mining reached crisis levels in 2017 and 2018, resulting in extensive deforestation (which was visible from the international space station), and mercury pollution. In their pursuit of gold, miners deforest landscapes, remove topsoil, and create mining ponds, resulting in landscapes that look like deserts in the middle of tropical rainforest. See photo above.
