Cyanidation of Mercury-Contaminated Tailings: Potential Health Effects and Environmental Justice
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There is a variety of health and environmental issues associated with artisanal and small-scale gold mining (ASGM), which includes concerns regarding mercury pollution. In many countries, intervention programs and policies emphasized the importance of reducing mercury use by focusing on viable alternative methods to amalgamation that may include a transition to cyanidation. ASGM communities that now employ a combination of both methods may be increasing health and environmental risks by using mercury-contaminated tailings in the cyanidation process. This review provides a current overview of mercury and cyanide use in ASGM including the dangers of centralized processing centers that lack best practices. The combination of amalgamation and cyanidation has the potential to adversely affect many ASGM communities around the world and necessitates additional investigations to determine environmental and health impacts.
KeywordsArtisanal and small-scale gold mining Mercury Amalgamation Cyanidation
The authors acknowledge the following support: UNIDO Project No.100271. We also thank Bruce G. Marshall for helpful comments and suggestions on the manuscript.
Compliance with Ethical Standards
Conflict of Interest
Kevin Drace, Adam M. Kiefer, and Marcello M. Veiga declare that they have no conflict of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
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- 5•.Gibb H, O’Leary KG. Mercury exposure and health impacts among individuals in the artisanal and small-scale gold mining community: a comprehensive review. Environ Health Perspect. 2014. This review provides an excellent summary of the published literature on the health impacts of mercury use by members of the ASGM community. Google Scholar
- 18.Veiga MM, Angeloci-Santos G, Meech JA. Review of barriers to reduce mercury use in artisanal gold mining. Extr Ind Soc. 2014;1:351–61.Google Scholar
- 20.Miller JD, Alfarol E, Misra M, Loreng J. Mercury control in the cyanidation of gold ores. Equilibrium. 1996;1:3–5.Google Scholar
- 22••.Veiga MM, Angeloci G, Hitch M, Colon Velasquez-Lopez P. Processing centres in artisanal gold mining. J Clean Prod. 2014;64:535–44 This article reports on the development of processing centers in developing countries and highlights potential health and environmental issues that can result from poor practices.CrossRefGoogle Scholar
- 23.Marsden J, House I. The chemistry of gold extraction, 2nd ed. Society for Mining, Metallurgy, and Exploration, Littleton, CO; 2006.Google Scholar
- 26.Coles CA, Cochrane K. Mercury cyanide contamination of groundwater from gold mining and prospects for removal. Sea Sky Geotech 2006;1118–1122.Google Scholar
- 29.Oraby EA, Jeffrey MI, Browner RE. The deportment of mercury during thiosulfate leaching and resin-in-pulp recovery of gold from ores. Miner Met Process J. 2010;27:184–9.Google Scholar
- 32.UNEP (United Nations Environment Programme). Mercury time to act. 2013.Google Scholar
- 33.AMAP/UNEP. Global mercury modelling: update of modelling results in the global mercury assessment 2013. Arctic Monitoring and Assessment Programme,, Oslo, Norway/UNEP Chemicals Branch. Geneva, Switzerland. 2015.Google Scholar
- 40.Kiefer AM, Drace K, Seney CS, Veiga MM. Challenges associated with using retorts to limit mercury exposure in artisanal and small-scale gold mining: case studies from Mozambique, Ecuador, and Guyana. In: Evans KR, Roberts-Kirchhoff ES, Benvenuto MA, et al., editors. Trace mater. Air soil water. Washington, DC: American Chemical Society; 2015. p. 51–77.CrossRefGoogle Scholar
- 44.Veiga MM, Bermudez D, Pacheco-Ferreira H, et al. Mercury pollution from artisanal gold mining in block B, El Callao, Bolívar State, Venezuela. In: Pirrone N, Mahaffey KR, editors. Dyn. Mercury Pollut. Reg. Glob. Scales atmospheric process. Hum. Expo. World. New York: Springer; 2005. p. 421–50.Google Scholar
- 45.WHO (World Health Organization). Elemental mercury and inorganic mercury compounds: human health aspects. 2003.Google Scholar
- 51•.García O, Veiga MM, Cordy P, et al. Artisanal gold mining in Antioquia, Colombia: a successful case of mercury reduction. J Clean Prod. 2015;90:244–52 The recent success of the Colombia Mercury Project in reducing mercury pollution is presented, providing a framework to consider when considering similar situations.CrossRefGoogle Scholar
- 53.WHO (World Health Organization). Exposure to mercury: a major public health concern. 2007.Google Scholar
- 54.Veiga MM, Baker RF, Fried MB, Withers D. Protocols for environmental and health assessment of mercury released by artisanal and small-scale gold miners. Global Mercury Project, UNIDO, Vienna. 2004.Google Scholar
- 62.Rubo A, Kellens R, Reddy J, et al. Alkali metal cyanides. Ullmanns Encycl Ind Chem. 2006.Google Scholar
- 67.McKinnon E et al. The environmental effects of mining waste disposal at Lihir Gold Mine, Papua New Guinea. J Rural Remote Environ Heal. 2002;1:40–50.Google Scholar
- 68.Ramraj R. The Omai disaster in Guyana. Geogr Bull. 2001;43:83–90.Google Scholar
- 69.Budavari S. The Merck index—an encyclopedia of chemicals, drugs, and biologicals. Whitehouse Station, NJ: Merck and Co., Inc.; 1996.Google Scholar
- 76.Hilson G, McQuilken J. Four decades of support for artisanal and small-scale mining in sub-Saharan Africa: a critical review. Extr Ind Soc. 2014;1:104–18.Google Scholar