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Minamata Convention on Mercury: ASGM
Minamata Convention on Mercury: ASGM

Understanding the Use, Release, and Effects of Mercury in Artisanal Gold Mining

Artisanal and small-scale gold mining (ASGM) is one of the world’s largest emitters of mercury in the environment, accounting for approximately one-third of all global emissions. Reducing mercury use within the ASGM sector requires a multi-disciplinary approach able to address technical, social, economic, and ecological issues that allow for new opportunities for sustainable devolopment. BRI works with multiple partners and governmental agencies towards this goal.

ASGM and Mercury

In the ASGM process, miners use elemental mercury to extract gold particles that have been ground and liberated from rock, a process called amalgamation. The mercury-gold amalam is then burned, releasing the mercury as a vapor and leaving the mined gold. 

During the small-scale gold mining process, some mercury is left in the silt (called mine tailings). This excess mercury often makes its way into surrounding waterways when tailings are disposed. In aquatic ecosystems, elemental mercury is converted to methylmercury (MeHg), which easily bioaccumulates through the food-web and is toxic to humans and wildlife. 

The release of mercury vapor during the amalgamation process is also of great concern, as it creates a high risk of human exposure for miners and their communities, as well as greater mercury deposition from the air into aquatic and terrestrial ecosystems through rainfall.

National Action Plans

National Action Plans

Article 7 of The Minamata Convention on Mercury stipulates that countries with ASGM activities in their territories must develop a National Action Plan outlining steps that will be taken to reduce, and where feasible eliminate, mercury use in the ASGM sector. 

In 2014, BRI worked with the Natural Resources Defense Council and a team of experts in mining and policy development to provide recommendations for the development of National Action Plans that reflect current requirements under the Minamata Convention. The resulting guidance document on National Action Plans was provided to UN Environment and presented to delegates at the Intergovernmental Negotiating Committee on Mercury (INC6)  held in Bangkok, Thailand, November 3-6, 2014.

ASGM Projects Worldwide

As a member of UN Environment's ASGM partnership area, BRI is working with organizations and government agencies across the globe to help countries reduce the use of mercury in ASGM practices, and to meet the requirements of the Minamata Convention on Mercury. Please click on projects below to learn more about efforts in each region:

BRI and collaborators are currently working to support the government of Indonesia in restricting mercury supplies for the ASGM sector through amending the draft National Implementation Plan, and by securely storing confiscated mercury, mercury by-products, and recovered mercury from the oil and gas sector at the local level.

South America
Together with collaborators in Peru, Colombia, and Ecuador, BRI has created modules for small-scale miners that introduce appropriate technologies to improve efficiency, increase gold recovery, and reduce reliance on mercury.

BRI contributed to the Integrated Assessment of ASGM in Ghana, which identifies policy-relevant solutions that will encourage economic development in the ASGM sector without compromising environmental and human health.

Photo Credits: Header photo: Sekotong ball-mills by Kemal Jufri; Mine tailings © BRI-Dave Buck.
Biodiversity Research Institute