CONICET | Buscador de Institutos y Recursos Humanos

Elevated concentrations of arsenic in water supplies represent a worldwide health concern. In at least 14 countriesof South America, high levels have been detected relative to international standards and guidelines.Withinthese countries, the high plateau referred to as the ?Altiplano-Puna?, encompassing areas of Argentina, Bolivia,Chile, and Perú, exhibits high arsenic concentrations that could be affecting 3 million inhabitants.The origins of arsenic in the Altiplano-Puna plateau are diverse and are mainly natural in origin. Of the naturalsources, themost important correspond to mineral deposits, brines, hot springs, and volcanic rocks, whereas anthropogenicsources are related to mining activities and the release of acidmine drainage (AMD). Arsenic is foundin all water types of the Altiplano-Puna plateau over a wide range of concentrations (0.01 mg·L−1 b As in waterN 10 mg·L−1)which in decreasing order correspond to:AMD, brines, salinewaters, hot springs, rivers affected byAMD, rivers and lakes, and groundwater. Despite the few studies which report As speciation, this metalloid appearsmostlyin its oxidized form(As[V]) and itsmobility is highly susceptible to the influence of dry andwet seasons.Once arsenic is released from its natural sources, it also precipitates in secondary minerals where it isgenerally stable in the form of saline precipitates and Fe oxides. In relation to human health, arsenic adaptationhas been detected in some aboriginal communities of the Puna togetherwith an efficientmetabolismof thismetalloid.Also, the inefficient methylation of inorganic As in women of the Altiplano might lead to adverse healtheffects such as cancer. Despite the health risks of living in this arsenic-rich environment with limited water resources,not all of the Altiplano-Puna is properly characterized and there exists a lack of information regardingthe basic geochemistry of arsenic in the region.