Artisanal gold mining polluting Peruvian biodiversity hotspot -study – by Valentina Ruiz Leotaud ( – November 17, 2019)

Researchers at Dartmouth College analyzed satellite data and discovered that artisanal mining is altering the water clarity and dynamics of the Madre de Dios River watershed in the Peruvian Amazon.

In a paper published in the Proceedings of the National Academy of Sciences, the researchers explained that higher levels of suspended sediment were found in rivers near the mining sites. The sediments contain mercury and other contaminants.

According to the Center for Amazonian Scientific Innovation, Canada’s NGO Artisanal Gold Council has registered that some 181 tonnes of mercury are released into the environment every year in the Madre de Dios region.

Such a massive, cumulative amount of pollutants is showing its effects now. “Significant impacts to rivers were observed as a result of the artisanal scale gold mining, with as much as 10 times normal suspended sediment concentrations—a measurement of how many sediment particles are in the water,” the Dartmouth scientists said in their report.

According to their study, though higher sediment concentrations were observed year-round, they were most pronounced during the dry season, when undisrupted rivers in this region of southeastern Peru generally run clear, with low sediment concentrations as compared to the wet season.

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