The use of mercury in gold mining has been a major cause of the health problems observed in mine workers, but also in the general population. Mercury is a heavy metal, highly toxic and polluting. Vapors released from heating the amalgam (mixture of ore and mercury) are extremely hazardous when inhaled. At the same time, the process of extraction with mercury involves a great risk of contamination of the water that serves the communities, who use it to drink, cook and water their gardens, resulting in serious poisoning. Psychosis, anxiety, depression, pneumonia and permanent damage to the brain and nerves are some of the consequences of mercury exposure which, adding to the strong impact on the environment, makes its banning imperative.
In 2017, medicusmundi, in partnership with Miners have since been encouraged to abandon the use of mercury and to use sodium borate (borax) instead. Borax is a cheaper, non-contaminating substance, that can be legally purchased (as opposed to mercury, prohibited for sale) and which allows for a considerably larger amount of gold to be extracted.and as part of the European Union-funded project “Artisanal Mining: Environmental and Cultural Rights in Cabo Delgado”, began a training cycle for artisanal miners in the districts of Ancuabe, Montepuez and Namuno to introduce cleaner and safer alternative gold extraction methodologies.
The artisanal processing of gold using borax follows the same sequence of tasks previously known and used by artisanal miners, with a difference in some techniques applied to improve the gold recovery yield. Other alternative methods are also suggested in the training process, such as replacing the dry ball mill, used in rock griding, with wet mills, as a way of reducing noise (and the resulting hearing problems), reducing gold waste and preventing the release of heavy metal dust which, when inhaled, is harmful to health.