Pervasive Arctic lead pollution suggests substantial growth in medieval silver production modulated by plague, climate and conflict
Proceedings of the National Academy of Sciences
Lead pollution in Arctic ice reflects large-scale historical changes in mid-latitude industrial activities such as ancient lead/silver production and recent fossil fuel burning. Here we used measurements in a broad array of thirteen accurately-dated ice cores from Greenland and Severnaya Zemlya to document spatial and temporal changes in Arctic lead pollution from 200 BCE to 2010 CE, with interpretation focused on 500 to 2010 CE. Detailed atmospheric transport modeling indicates that Arctic lead pollution was primarily from European emissions prior to the 19th-C. Industrial Revolution. Temporal variability was surprisingly similar across the large swath of the Arctic represented by the array, with 250- to 300-fold increases in lead pollution observed from the early Middle Ages to the 1970s industrial peak. Superimposed on these largely population-driven changes were pronounced, multi-annual to multi-decadal variations, marked by increases coincident with exploitation of new mining regions, improved technologies, and periods of economic prosperity; and decreases coincident with famines, climate disruptions, famines, major wars, and plagues. Our results suggest substantial overall and per capita growth in lead/silver mining and smelting emissions — and so silver production — during the Early Middle Ages, with lower or negative per capita growth during the High and Late Middle Ages and into the Earlypre-industrial MModern Period, particularly in northern Europe. Near the end of the 2nd Pandemic, lead pollution growth accelerated sharply and continued through the 2nd Industrial Revolution. Pollution abatement policies in the mid-latitudes have reduced Arctic lead pollution by >80% since the 1970s, but recent levels remain ~60-fold higher than at the start of the Middle Ages.
LEAD, LEAD POLLUTION, MINING, MEDIEVAL, ATMOSPHERIC POLLUTION, ATMOSPHERIC PB, ARCTIC, ICE CORES, GREENLAND, AKADEMII NAUK, HARZ MOUNTAINS, ERZGEBIRGE MOUNTAINS, PLAGUE, ECONOMIC HISTORY