3400 Years of Mercury Pollution
Thursday, 28. May 2009, 19:39:54
Intensive mining of mercury (Hg) began around 1400 BC in the central Peruvian Andes.
Cinnabar (HgS or mercuric sulphide) is the primary natural source of mercury (Hg), and forms a bright red pigment (vermillion) when powdered. In the Andes vermillion was used as either a body paint or a covering on ceremonial gold objects from the first (Chavín) to the last (Inca) Andean empires.
PhD student Colin Cooke’s results from two seasons of field work in Peru have now provided the first unambiguous records of pre-industrial mercury pollution from anywhere in the world. His findings are published in the 18 May 2009 Early Edition of the Proceedings of the National Academy of Sciences (PNAS).
Cooke and his team recovered sediment cores from high elevation lakes located around Huancavelica, which is the New World’s largest mercury deposit. By measuring the amount of mercury preserved in the cores back through time, they were able to reconstruct the history of mercury mining and pollution in the region.
Mining appears to have began before the rise of any complex or highly stratified society (around 1400 BC). The mercury amounts peaked, however, at about 500 BC (the height of the Chavín culture) and again about 1450 AD (the height of the Inca culture, with Inca expansion into the central Andes). In between, by 800 AD, there was a brief renewal in cinnabar mining. Inca mining continued until 1564 AD when the Spanish crown assumed control,
During the Colonial era (1532–1900 AD), large-scale mercury mining began in earnest with the invention of mercury amalgamation in 1554 AD by Bartolomé de Medina in Mexico. For the next 350 years, mercury amalgamation became the dominant silver processing technique because it allowed for the extraction of silver from low-grade ores. Spanish efforts thus concentrated on supplying mercury to Colonial silver mines for use in amalgamation. Cinnabar ores from Huancavelica were smelted in grass-fired, clay-lined retorts, until vaporization yielded mercury gases, a portion of which was trapped in a crude condenser and cooled, yielding liquid mercury. Emissions of mercury thus occurred both during mining, as cinnabar dust, but also during cinnabar smelting, as gaseous mercury.
Frequent cave-ins and extensive mercury poisoning throughout Huancavelica’s 450-year Colonial history have made it one of the most sinister examples of human exploitation and disastrous mining environments ever documented, earning it the nickname mina de la muerte (mine of death).
Reference:
Cooke, C., P. Balcom, H. Biester, and A. Wolfe (2009).
Over three millennia of mercury pollution in the Peruvian Andes, Peru.
Proceedings of the National Academy of Sciences USA
doi:10.1073/pnas.0900517106
• http://www.pnas.org/content/early/2009/05/15/0900517106.abstract
• http://www.science.ualberta.ca/news.cfm?story=91226
• http://research.eas.ualberta.ca/cooke/Colin_Cookes_Webpage/Research.html
Cinnabar (HgS or mercuric sulphide) is the primary natural source of mercury (Hg), and forms a bright red pigment (vermillion) when powdered. In the Andes vermillion was used as either a body paint or a covering on ceremonial gold objects from the first (Chavín) to the last (Inca) Andean empires.
PhD student Colin Cooke’s results from two seasons of field work in Peru have now provided the first unambiguous records of pre-industrial mercury pollution from anywhere in the world. His findings are published in the 18 May 2009 Early Edition of the Proceedings of the National Academy of Sciences (PNAS).
Cooke and his team recovered sediment cores from high elevation lakes located around Huancavelica, which is the New World’s largest mercury deposit. By measuring the amount of mercury preserved in the cores back through time, they were able to reconstruct the history of mercury mining and pollution in the region. Mining appears to have began before the rise of any complex or highly stratified society (around 1400 BC). The mercury amounts peaked, however, at about 500 BC (the height of the Chavín culture) and again about 1450 AD (the height of the Inca culture, with Inca expansion into the central Andes). In between, by 800 AD, there was a brief renewal in cinnabar mining. Inca mining continued until 1564 AD when the Spanish crown assumed control,
During the Colonial era (1532–1900 AD), large-scale mercury mining began in earnest with the invention of mercury amalgamation in 1554 AD by Bartolomé de Medina in Mexico. For the next 350 years, mercury amalgamation became the dominant silver processing technique because it allowed for the extraction of silver from low-grade ores. Spanish efforts thus concentrated on supplying mercury to Colonial silver mines for use in amalgamation. Cinnabar ores from Huancavelica were smelted in grass-fired, clay-lined retorts, until vaporization yielded mercury gases, a portion of which was trapped in a crude condenser and cooled, yielding liquid mercury. Emissions of mercury thus occurred both during mining, as cinnabar dust, but also during cinnabar smelting, as gaseous mercury.
Frequent cave-ins and extensive mercury poisoning throughout Huancavelica’s 450-year Colonial history have made it one of the most sinister examples of human exploitation and disastrous mining environments ever documented, earning it the nickname mina de la muerte (mine of death).
Reference:Cooke, C., P. Balcom, H. Biester, and A. Wolfe (2009).
Over three millennia of mercury pollution in the Peruvian Andes, Peru.
Proceedings of the National Academy of Sciences USA
doi:10.1073/pnas.0900517106
• http://www.pnas.org/content/early/2009/05/15/0900517106.abstract
• http://www.science.ualberta.ca/news.cfm?story=91226
• http://research.eas.ualberta.ca/cooke/Colin_Cookes_Webpage/Research.html
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