Department of Biology, Duke University, Durham, NC 27708, USA.
Department of Geological Sciences, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599, USA.
Sci Adv. 2020 Nov 27;6(48). doi: 10.1126/sciadv.abd4953. Print 2020 Nov.
Artisanal and small-scale gold mining (ASGM) is the largest global source of anthropogenic mercury emissions. However, little is known about how effectively mercury released from ASGM is converted into the bioavailable form of methylmercury in ASGM-altered landscapes. Through examination of ASGM-impacted river basins in Peru, we show that lake area in heavily mined watersheds has increased by 670% between 1985 and 2018 and that lakes in this area convert mercury into methylmercury at net rates five to seven times greater than rivers. These results suggest that synergistic increases in lake area and mercury loading associated with ASGM are substantially increasing exposure risk for people and wildlife. Similarly, marked increases in lake area in other ASGM hot spots suggest that "hydroscape" (hydrological landscape) alteration is an important and previously unrecognized component of mercury risk from ASGM.
手工和小规模采金（ASGM）是人为汞排放的最大全球来源。然而，人们对于 ASGM 释放的汞在 ASGM 改变的景观中转化为生物可利用的甲基汞的效率知之甚少。通过对秘鲁受 ASGM 影响的河流流域进行研究，我们发现，在 1985 年至 2018 年间，受严重开采影响的流域中的湖泊面积增加了 670%，而该地区的湖泊将汞转化为甲基汞的净速率比河流高五到七倍。这些结果表明，与 ASGM 相关的湖泊面积和汞负荷的协同增加，大大增加了人类和野生动物的暴露风险。同样，在其他 ASGM 热点地区湖泊面积的显著增加表明，“水景观”（水文景观）的改变是 ASGM 产生汞风险的一个重要且以前未被认识到的组成部分。
