Artisanal, or small scale gold mining (also called ASM) is one of the most significant sources of mercury release into the environment in the developing world, with at least a quarter of the world’s total gold supply coming from such sources. ASM miners combine mercury with gold-carrying silt. The gold and mercury combine to form an amalgam, making recovery of the gold easier. The amalgam is subsequently heated with blow torches or over an open flame so that the mercury burns off, and gold is left at a purity of 70 to 80 percent. The gaseous mercury is subsequently inhaled by the miners, or by their immediate family, including their children. Mercury which is not inhaled during the amalgamation process settles into the surrounding environment, or circulates globally at regional and global scales for future deposition far from the site, where it is absorbed and processed by a variety of living organisms. As a consequence of its misuse, mercury amalgamation results in the discharge of an estimated 1000 tons of mercury per annum which represents about 30% of the world’s anthropogenic mercury releases. It is estimated that between 10 and 15 million artisanal and small scale gold miners worldwide, including 4.5 million women and 600,000 children1. This process transforms elemental mercury into methylmercury. Methylmercury is one of the most toxic organic compounds and a powerful neurotoxin that works its way up the food chain through bioaccumulation. According to UNIDO, as much as 95 percent of all mercury used in ASM mining is released into the environment, constituting a danger on all fronts – economic, environmental and human health. There are a number of cleaner technology alternatives to current methods of mercury amalgamation. The use of retorts during the mercury burn-off stage is a simple and cost-effective way to decrease the occupational exposure to mercury and minimize its release into the environment. Retorts allow for the efficient capture and reuse of mercury. 1 Veiga, M.M., Baker, R. (2004). Protocols for Environmental and Health Assessment of Mercury Released by Artisanal and Small Scale Miners, Report to the Global Mercury Project: Removal of Barriers to Introduction of Cleaner Artisanal Gold Mining and Extraction Technologies, GEF/UNDP/UNIDO, 170p.

UNIDO estimates that mercury amalgamation from this kind of gold mining results in the release of an estimated 1,000 tons of mercury per year, which constitutes about 30 percent of the world’s anthropogenic mercury emissions. It is estimated that between 10 and 15 million artisanal and small-scale gold miners worldwide, including 4.5 million women and 600,000 children [1]. According to UNIDO, as much as 95 percent of all mercury used in artisanal gold mining is released into the environment, creating a danger on all fronts—economic, environmental and human health (2005). Covered by the 2008 World’s Worst Polluted Places Report, ASM still threatens today’s world environment and public health.

Cambodia is amongst the poorer countries in the world, ranking 130 or 177 countries in the 2003 Human Development Index, as reported by the UN. The GNI per capita in 2004 was $320, while life expectancy was 57 years. Mortality due to waterborne illnesses is high, in part reflecting the fact that many Cambodians have less access to adequate sanitation and clean drinking water compared to other Asian nations. The country is still struggling to recover from recent civil war (1970-5), and Khmer Rouge tragedy (1075-9) and subsequent occupation by Vietnam (1979-89). A generation of technically-skilled people was killed or fled the country and all government institutions were mantled. As such, there is a great need to capacity building in the areas of natural resource, environment, and basic health management.

The province of Ratanakirri is an isolated underdeveloped area of northeast Cambodia with a small population of about 72,000. About 80% of the people are tribal who subsist by slash and burn agriculture and fishing. Gold and gem stones are fathered in crude mines at times using mercury to extract gold. A review by Sotham (2004) estimated that about 1000 miners are working at six Prey Meas mines. They use mercury amalgamation, without retorts, to extract the gold. The concentration of mercury in the hair of the miners was extremely high; in April 2006 retorts were successfully introduced into a goldmine in Prey Meas to recover mercury. The technology was readily understood, and the miners were glad to be both protecting their health and recouping some of their expense. This initial project was quite small and more effort should be directed at introduction of retorts at more mines. Any effort to introduce retorts at more mines should be associated with an attempt to measure the total amount of mercury escaping from the mines. The objective of this project is to reduce the negative, mercury-related, community health impacts of artisanal gold mining operations.