Water for people.pdf - WHO Thailand Digital Repository

P R O M O T I N G C L E A N E R I N D U S T R Y F O R E V E R Y O N E ’ S B E N E F I T / 2 4 3Box 9.6: Removal of barriers for cleaner artisanal gold miningOver the last few decades, artisanal gold mining activitieshave increased steadily and account now for approximatelyone-quarter of total world gold output. Despite thecurrent low gold price, this gold rush in the artisanalsector continues. In many developing countries, artisanalgold mining has become a major safety valve, cushioningthe worst effects of structural adjustment, recession anddrought by providing people in the rural areas with analternative way of securing a livelihood.However, water siltation resulting from small-scale goldmining along rivers has resulted in a decrease of the fishpopulation and has made water unfit for human consumptionin regions where this resource was already scarce.Most small-scale miners use mercury amalgamation toprepare final gold concentrates. Mercury is one of the mosttoxic substances in the world with long-term and farreachingeffects causing significant damage to theenvironment and to the health of people who handle it. Themercury released into watercourses travels long distancesand can be transformed by micro-organisms into more toxicforms (methyl-mercury), which then enter the food chain.It is estimated that 2 to 5 grams of mercury arenecessary to produce 1 gram of gold and that, with themethods currently used, all this mercury is lost to theenvironment. In addition to mercury discarded or spilleddirectly into streams and rivers during the amalgamationprocess, a considerable volume of mercury vapour isreleased each year to the atmosphere. Much of thisquickly returns with rain to the river ecosystem.The environmental impacts resulting from mercury useby the artisanal mining sector require concerted andcoordinated global responses. In recent years, UNIDO hasdeveloped projects to address the problem in Ghana, thePhilippines, the United Republic of Tanzania and Zimbabwe.Through training campaigns, miners are informed of thedangers of mercury, are trained in improved mining andprocessing practices, and are made aware of the need toprotect water resources, both for their own use and for theuse of communities living downstream. Alternative cleanertechniques to amalgamation are demonstrated on-site andthe technology then transferred to local manufacturers.Retorts, which allow the recycling of mercury during theburning process are introduced, thereby reducingenvironmental releases and reducing overall mercuryconsumption. Local laboratory capacities are also enhancedto monitor the environmental and human health impacts ofthe mining activity on the rivers. UNIDO also assistsgovernments in the development of monitoring andenforcement programmes.UNIDO has recently won approval for GEF funding for aglobal project that plans to address mercury pollutioncaused by small-scale mining activities undertaken in Brazil,Indonesia, Lao PDR, Sudan, the United Republic ofTanzania and Zimbabwe as well as seeking to reducemining-related risks to international water bodies such asLake Victoria, the Amazon, Mekong, Nile and ZambeziRivers and the Java Sea. The strength of this global projectlies in the exchange of experience between the countriesand the facilitation of technology transfer. The project willreduce the environmental burden of artisanal gold miningon watercourses and public health while at the same timeimproving the skills and income of small-scale miners.friendly, increases productivity, reduces costs by cutting water,energy and chemical consumption, and strengthens themanufacturer’s image. Water savings made in this way may beallocated to other uses while improved water quality restoresecosystem functioning and potable water resources.A similar experience in food-processing enterprises in Viet Namindicates that significant reductions in water consumption inemissions can be achieved by introducing cleaner productionmethodologies, often with little or no capital investment in earlystages (see box 9.5).The introduction of cleaner technologies for the artisanal goldmining activities (see box 9.6) provides an example of actions toaddress local water contamination issues where the hazard is lessobvious to industry and affected communities. Improving themanagement of mercury within the gold amalgamation processreduces consumption and significantly reduces mercury releases tothe environment, reducing risks to both human and ecosystem health.