Mine ponds amplify mercury risks in Peru’s Amazon
The proliferation of pits and ponds created in recent years by miners dredging for small deposits of alluvial gold in Peru’s Amazon has dramatically altered the landscape and increased the risk of mercury exposure for indigenous communities and wildlife, a new study shows. The study found a 670% increase in the extent of ponds across the landscape in heavily mined watersheds since 1985. These formerly forested landscapes are now dotted by these small lakes, which provide low-oxygen conditions in which submerged mercury—a toxic leftover from the mining process—can be converted by microbial activity into an even more toxic form of the element, called methylmercury. The miners use mercury, a potent neurotoxin, to separate ore from soil and sediments, often without adequate safety precautions. Artisanal and small-scale gold mining (ASGM) is believed to be the largest global source of anthropogenic mercury emissions. (Photo via EurekaAlert!)