Borax – an alternative to mercury for gold extraction by small-scale miners: introducing the method in Tanzania

Small-scale mining is extraction of metals, precious stones, industrial minerals and other commodities using simple technologies. At a worldwide scale, an estimated 100 million people depend on income from small-scale mining (Hinton 2006). In Tanzania, there are more than half a million active small-scale miners, most of whom extract gold from placer and hard-rock deposits. Apart from providing a livelihood for thousands of households, small-scale mining reduces migration from rural to urban areas. However, small-scale mining is associated with a number of negative effects, because mining activities have severe impacts on both the local environment and the miners’ health. Most significantly the widespread use of mercury for gold extraction results in polluted environments and serious health hazards for the miners themselves and for the population in the vicinity of smallscale gold mining settlements (Bose-O’Reilly et al. 2008a, b; 2010; Jønsson et al. 2009).