Artisanal and Small-scale Gold Mining represents the largest anthropogenic source of mercury emissions to the air. Miners use mercury to amalgamate the gold, separating it from unwanted gangue minerals. Subsequent heating of the amalgam reveals the doré, or sponge gold, that still contains ~5% by mass Hg. The heating of the amalgam or reheating of the doré often occurs in gold shops located in residential or business areas of urban centers, releasing mercury vapor into populated areas. From 2014-2017, mercury concentrations were measured in and around gold shops in Portovelo and Zaruma, Ecuador using portable atomic absorption spectrometers. The results demonstrate that these gold shops release large quantities of Hg into the air that dissipates rapidly into the surrounding environment. Concentrations on the street and sidewalk of these shops can exceed 2,000,000 ng/m3. Data collected in 2017 was done so after the Hg ban in Ecuadorian ASGM, and indicates that gold shops remained a major source of Hg pollution in the region. This data serves as a baseline for future remediation projects in the region, and can also be used to test the effectiveness of the Hg ban in the region.

Mapping elemental mercury emissions from gold shops in Portovelo and Zaruma, Ecuador: 2014-2017

2019 Spring National Meeting

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