By: Mark Staples
Artisanal and small-scale gold mining (ASGM) is a source of income for around 15 million miners in the developing world. Mercury is often used to separate and purify the gold from the soil and other sediments in the whole ore, and to pick up small amounts of gold.
Despite the environmental damage and health costs mercury causes, when it is boiled off from the gold-mercury amalgam, this practice is still widespread. Globally, over 700 tonnes of mercury are emitted to the atmosphere from ASGM each year, with over 800 tonnes released to land and water. These local releases can create significant health impacts in nearby communities.
In most developed nations, the use of mercury in industrial processes has tapered off as public awareness of its toxicity has grown. However, high gold prices continue to incentivize ASGM operations. As a result, mercury prices are correlated with gold prices.
Mercury mines are still open, primarily in China, and these sources provide a steady supply of mercury for ASGM operations in the developing world. In fact, a significant proportion of the mercury that is imported to ASGM countries and their neighbors is either mined in, or transported via, developed nations. This study provides some interesting insight into the global flows of primary mercury to ASGM practicing nations.
One of the greatest challenges for understanding the contribution of ASGM to anthropogenic releases of mercury to the environment is a lack of transparency and completeness of data. For example, the United Nations Commodity Trade Statistics Database (COMTRADE), used in a number of analyses of the global flow of commodities like mercury, is voluntary and incomplete. Further, mercury is almost never officially traded for the stated purpose of gold amalgamation, making it harder to track.
While many countries, including China, Brazil, French Guiana and Indonesia, have laws in place to monitor or limit the use of ASGM operations, large volumes of mercury are still imported for gold mining. Mercury is often imported for ostensibly legal use in dental amalgams, but is then made available to miners in chemical or dental shops once inside the country. The ease with which miners can obtain this neurotoxin is alarming.
At the negotiations, delegates focused heavily on ASGM on January 14 at INC5. The proposed text, Article 9, addresses ASGM; parties are debating whether continued use of mercury should be permitted or whether it should be phased out. Brazil, Mali and the Alliance for Responsible Mining (an industry group), all voiced support for the continued, legal international trade of mercury for ASGM. These delegations argued that ASGM is going to happen regardless of the outcome of these negotiations because it occurs in the informal sector. Banning mercury trade would only criminalize an important economic activity in developing nations. Instead of effectively discouraging the international trade of mercury, a phase out of the permissible import of mercury for ASGM might simply force the trade underground.
I’m not so näive as to believe that including a phase-out date for the legal trade of ASGM-destined mercury in the treaty would be entirely effective. In all likelihood, the illicit trade in mercury that already exists will simply grow to fill that gap. However, I do believe that better monitoring and reporting on ASGM-destined mercury, in preparation for a legally binding phase-out, could only aid in getting a handle on this harmful trade and on the extent of ASGM as an informal practice. It would also allow miners and developing nations to transition to alternative ASGM techniques, such as gravity concentration, sluice boxes or cyanidation.
There is clearly some cognitive dissonance in the way in which mercury is traded and used by importing and exporting nations. It seems to me that this is an issue that needs to be resolved to help stem the flow of mercury that is harmful to both human health and the environment. I’m excited to see the progress that will be made on this issue this week.
For more information about ASGM, you can check out the NGO Artisanal Gold Council’s site and the recent report from Human Rights Watch. Here is a short video which explains how ASGM with mercury works: