Fact Sheet - Artisanal Gold Mining and
Mercury Pollution
Estimated Population at Risk at Identified Sites: 3.5 Million People*
Estimated Global Impact: 5 to 8 Million People*
What Is Artisanal Mining?
Artisanal mining refers to small-scale mining operations that are often done by hand and consist of basic extraction and processing methods for obtaining minerals and metals. Artisanal miners often use toxic materials to separate gold from the surrounding rock and silt.
How Is Mercury Used in Artisanal Gold Mining?
The most common practice used in artisanal mining to separate gold from ore is mercury amalgamation. The amalgamation process is performed by combining mercury with silt that contains pieces of gold. The mercury binds to the flakes of gold and forms a solid mercury-gold amalgam. This amalgam is then heated to vaporize the mercury, leaving behind the gold.
What Are the Human Exposure Pathways for Mercury from Artisanal Mining?
The artisanal gold mining process can lead to mercury exposure through inhalation and ingestion. Vapor mercury is released into the air when the amalgam is heated, and is frequently inhaled by miners and their families. Excess liquid mercury used in the amalgamation process is often washed away with the remaining silt and can enter into water systems and accumulate in fish, contaminating the food chain for communities downstream. Though mercury most commonly accumulates in large, predatory fish, traces have also been found in birds, reptiles, and mammals, all of which can spread mercury to humans if consumed.
What Are the Health Risks Associated with Mercury?
The health hazards that result from exposure to mercury depend on the type of mercury, the level of exposure and the way in which the pollutant enters the body. Inhalation of mercury vapor is particularly hazardous for kidneys, the central nervous system, and the respiratory and cardiovascular systems.1 Exposure to other forms of mercury, and in particular the methylmercury that accumulates in fish, can also lead to problems with the kidneys, lungs, and central nervous system, in addition to arthritis, reproductive problems, loss of memory, psychosis, and in some cases, death. Children exposed to mercury contamination have a higher risk of developmental problems.
*Population estimates are preliminary and based on an ongoing global assessment of polluted sites.
Footnotes
[1]: Toxicological Profile for Mercury.” U.S. Department of Health and Human Services. March, 1999. Available at http://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=115&tid=24.
