The Minamata Convention on Mercury and Artisanal and Small Scale Gold Mining

Fact Sheet
Bureau of Oceans and International Environmental and Scientific Affairs

The Minamata Convention on Mercury is increasing global interest in mercury pollution reduction activities, particularly in the area of Artisanal and Small Scale Gold Mining (ASGM). For most developing countries, ASGM is the largest source of mercury pollution. According to UNEP’s most recent Global Mercury Assessment in 2013, ASGM is currently the largest source of mercury pollution in the world, accounting for more than 35% of total anthropogenic emissions. Read more here.

Under the Minamata Convention, countries will identify nationally determined measures to address mercury use in ASGM. The Convention provides this flexibility in recognition of the complex challenge from this sector, and the reality that drivers of mercury use in ASGM activities vary from country to country. Mercury Program projects managed by the Bureau of Oceans and International Environmental and Scientific Affairs (OES) will continue with replicable and scalable projects aimed at reducing mercury use in the ASGM sector, and, going forward, will contribute to the development of a global “toolbox” of best-practice models and information resources.

ASGM refers to gold mining conducted by individual miners or small enterprises with limited capital investment and production. Miners often resort to using mercury to extract gold from ore because it is relatively inexpensive and easy to use. Alternative methods exist to extract gold, often with higher yields. Due to the rise of gold prices over the past decade, the ASGM sector now provides the main source of income for 10 million to 20 million miners in more than 70 countries, primarily developing nations. The secondary economy surrounding ASGM supports 50 million to 100 million people around the globe. The World Bank and other agencies consider ASGM to be a potential source of economic development and poverty relief. Mining incomes are often two to four times higher than incomes from typical agricultural activities in the same region. Even if the price of gold were to drop by 25 percent, ASGM will remain an attractive activity for the rural poor.

Mercury is used in ASGM to concentrate gold by forming a mercury-gold amalgam, which is then heated to drive off the mercury into the atmosphere, leaving only the gold. This process is favored by small-scale miners over other methods of gold extraction because it is inexpensive, accessible, simple to use, and allows miners to produce gold quickly, often in a single day.

Nearly all of the mercury used in ASGM is eventually released directly into the environment. Those who burn the gold-mercury amalgam and whoever is nearby are exposed to mercury vapors released into the air through inhalation. Mercury-contaminated tailings are released to soils and waters. This mercury pollutes the atmosphere, soils and waterways, exposing miners and their communities to serious health risks. Mercury released into air can also travel long distances, reaching lakes, streams, and soils all around the world.

Technical solutions already exist that could dramatically lower the use and release of mercury in ASGM, and in numerous cases, eliminate the need for mercury all together. These technologies include better pre-concentration of gold prior to amalgamation, decreasing the amount of mercury needed; capture, re-activation, and re-use of mercury; and mercury-free gravity separation technologies. Some researchers have estimated that if all of these techniques were applied together, they would reduce global use of mercury in ASGM as much as 90%.

The Minamata Convention on Mercury, an international agreement adopted in 2013 and signed by 128 countries (but not yet in force), addresses mercury use in ASGM among other forms of mercury pollution. The Convention does not require a ban of mercury use in ASGM, although restrictions on the supply and trade of mercury will likely make it more expensive and difficult to acquire. Rather, Article 7 of the Minamata Convention requires that countries with ASGM using mercury in their territory take steps to reduce and where feasible eliminate the use of mercury in ASGM. Countries where mercury use in ASGM is more than insignificant must also submit a National Action Plan that describes how they will achieve mercury reductions. The annex of the Convention guides countries on creating their National Action Plans. Among other requirements, countries must identify and take actions to eliminate some of the worst practices associated with ASGM, including whole ore amalgamation (an intensive use of mercury causing some of the worst pollution). Countries must also take steps to facilitate regulation of the ASGM sector into the formal economy.

ASGM is considered an “allowable use” under the Convention, which means that mercury can be imported and exported for use in this sector. However, there will be restrictions on this trade. Exporting countries must notify and receive consent from importing countries. Further, mercury from primary mining and legacy mercury from the chlorine manufacturing sector (large sources of mercury supply) cannot be used for ASGM.

The international community can help to address the challenge of reducing, or where possible, eliminating the use of mercury in ASGM through education programs, financial mechanisms for investment in better technologies, and support to government to create enabling policies to support the miners’ participation in the formal economy.

Before the Convention was negotiated, international efforts were underway to provide guidance and tools, and to facilitate funding of projects to reduce mercury use in ASGM, including through the United Nations Environment Programme (UNEP) Global Mercury Partnership. Further, a number of bilateral and multilateral-funded projects have been undertaken to address a wide array of social, economic and environmental dimensions of the ASGM sector. These efforts represent a body of existing global experience that can be drawn upon to help countries devise strategies to comply with their obligations under the Minamata Convention.