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| Last Updated:06/07/2020

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Mining brought pollution 240 years before industrial revolution

                                                                                                                 The Hindu, New Delhi, 11th February, 2015

 Divya Gandhi


Ice core records from the Quelccaya ice cap in Peru, provided the evidence. Photo: Reuters



Frozen beneath layers of mountain ice in Peru, scientists have found toxic trace metals that point to sources of pollution 240 years before the industrial revolution.


Researchers who studied ice core records from the high-altitude Quelccaya ice cap (in Peru) found “archives” of preindustrial trace elements, which they have traced back to 16 century colonial silver-mining operations in Potosí (now Bolivia). Quelccaya is one of the few sites on Earth where pre-industrial pollution of air caused by human activity can be studied today.


Around 1540, the Spanish Empire forced Incas to work on extracting silver in Potosí’s mountaintop mines, the main source of silver at the time. The pollution from the mining and smelting activities was carried by the wind 500 miles northwest into Peru where it settled on the Quelccaya ice cap, says a paper published in the Proceedings of the National Academy of Sciences.


Spanish Conquistadors, who were mainly interested in silver, saw a technological breakthrough in 1572 with a mercury amalgamation process, which triggered an unprecedented mining boom across the Andes. The Incas, who also knew how to refine silver, used a “huyara” or wind-drafted furnace made of clay.


Researchers used a mass spectrometer to identify chemicals — including arsenic, chromium and lead — present in the ice, starting from 800 AD. After the demise of the Inca Empire (A.D. 1532), the concentrations and trace elements increased, they found.


Unlike in the case of other continents, trace element deposition arising from human activity in the 20 Century started later in South America. However, the deposition was several times higher than during the Colonial period.


The deposition during the Colonical period, in turn, was several times higher than during the Inca Empire “when natural fluxes for the region dominated.”