Workers' Health and Colonial Mercury Mining at Huancavelica, Peru

Mining had far-reaching ecological consequences throughout much of colonial Spanish America. ¹ It deformed the landscape, introduced pollutants such as sulfur, mercury and salt into the biosphere, and caused human settlement of sparsely populated or uninhabited regions. Forests succumbed to the charcoal makers' axes. ² Workers' lungs filled with silicosis-causing dust. Cave-ins snuffed out lives or crippled those they spared.

As unhealthy as mining was elsewhere in Spanish America, it was reported to have been especially harmful in the central Andes at Huancavelica. ³ Workers there suffered the common diseases and injuries associated with the industry such as respiratory disease and broken limbs. They also had to overcome the challenges of arduous labor at high altitude. Most pernicious of all was the toxic nature of the mercury they were mining. Colonial critics asserted that Huancavelica was an environmental tragedy that placed workers in exceptionally dangerous conditions in order to produce the mercury needed by silver refiners to amalgamate and refine their ores. The critics claimed that the mercury mines' human cost was immoral, yet their cries of despair and outrage could not overcome quicksilver's crucial importance to the imperial economy. Killing and maiming, Huancavelica earned for itself an infamous reputation as the mina de la muerte (the mine of death).

The following analysis examines the consequences for workers' health of colonial Huancavelica. One of its aims is to describe the environmental impact of Huancavelica's mines and refining plants on those who worked there. Early modern mining was, of course, unhealthy everywhere, not only Huancavelica. Because it is important to provide some basis for evaluating Huancavelica's dangers, this study makes a number of comparative references to conditions at Almadén, the Spanish crown's other mercury mines, as a way of placing Huancavelica's dangers in historical context. The documentary record for Almadén also contains medical descriptions of mercury toxicology suffered by early modern mine workers, and some of these are included to supplement the surviving documentary evidence from Huancavelica about the health risks confronted by mercury miners. Of course, the true dimensions of mercury toxicology are much clearer to modern science than they were to observers at Huancavelica and Almadén. Therefore, this study also refers to modern medical and environmental literature to show how extensively mercury contaminated workers and their environment. Another aim is to evaluate how Huancavelica's working conditions changed over time and to what extent the mines' horrific reputation remained valid later in the colonial period. The study divides the mines' history into three main periods, which reflect technological and environmental changes at Huancavelica that affected working conditions. This permits a more nuanced treatment of how those conditions changed over the colonial era. A final objective is to determine the level of mortality caused by the Huancavelica mercury mines. Colonial critics claimed that Huancavelica slaughtered Andeans forced to labor there. Lack of specific data makes it impossible to calculate precise mortality rates for Huancavelica's workers, but it is possible to glean a rough idea of how many deaths the mines caused and how mortality rose and fell over the colonial period.

Andeans had mined the Huancavelica deposits before the Spaniards' arrival. They extracted bright red llimpi or cinnabar (mercuric sulfide) which they used in sacrificial rites, for painting warriors' bodies, and as cosmetics for the Inca's wives and other elite women. ⁴ They probably also collected native mercury. After the kuraka (ethnic lord) of the Angaraes people revealed the large and exceptionally rich cinnabar deposits to Amador de Cabrera in late 1563, he and other Spaniards staked claims and began mining cinnabar and distilling mercury. Initially they sold it to Mexico, where silver refiners used it to amalgamate their ores. When amalgamation was adapted to the ores at Potosí in the early 1570s, demand for Huancavelica's mercury surged. After 1580 Potosí's Spanish refiners turned almost exclusively to amalgamation and depended...