Huancavelica was the primary source of mercury used in silver refining in the Andes during the colonial period, and production continued there into the twentieth century. Between 1564 and 1975, when large scale mercury production in Huancavelica finally ceased, estimated 25,000 metric tons of mercury vapor escaped during refining operations. Refining also released arsenic and lead, leaving a noxious legacy of heavy metal contamination in the city.
Among the results is that that Huancavelica is among the most mercury contaminated urban areas in the world.
Today, Huancavelica’s 49,000 residents shoulder this toxic burden on a daily basis.
Thousands have constructed their modest dwellings from adobe made from local contaminated soil. Particle-bound mercury, arsenic and lead are released from the walls and floors as dust, which deposits on surfaces and foods, and is ingested through normal hand-to-mouth activity. Worse is the off-gassing of elemental mercury from the floors and walls of these homes, which exposes residents to risks through inhalation exposure.