Division of Hydrologic Sciences, Desert Research Institute, Reno, NV 89512;
Visiting Fellow, All Souls College, University of Oxford, OX1 4AL Oxford, United Kingdom.
Proc Natl Acad Sci U S A. 2018 May 29;115(22):5726-5731. doi: 10.1073/pnas.1721818115. Epub 2018 May 14.
Lead pollution in Arctic ice reflects midlatitude emissions from ancient lead-silver mining and smelting. The few reported measurements have been extrapolated to infer the performance of ancient economies, including comparisons of economic productivity and growth during the Roman Republican and Imperial periods. These studies were based on sparse sampling and inaccurate dating, limiting understanding of trends and specific linkages. Here we show, using a precisely dated record of estimated lead emissions between 1100 BCE and 800 CE derived from subannually resolved measurements in Greenland ice and detailed atmospheric transport modeling, that annual European lead emissions closely varied with historical events, including imperial expansion, wars, and major plagues. Emissions rose coeval with Phoenician expansion, accelerated during expanded Carthaginian and Roman mining primarily in the Iberian Peninsula, and reached a maximum under the Roman Empire. Emissions fluctuated synchronously with wars and political instability particularly during the Roman Republic, and plunged coincident with two major plagues in the second and third centuries, remaining low for >500 years. Bullion in silver coinage declined in parallel, reflecting the importance of lead-silver mining in ancient economies. Our results indicate sustained economic growth during the first two centuries of the Roman Empire, terminated by the second-century Antonine plague.
北极冰中的铅污染反映了中纬度地区古代铅银开采和冶炼的排放。少数已报道的测量结果被推断为推断古代经济的表现，包括罗马共和国和罗马帝国时期的经济生产力和增长比较。这些研究基于稀疏的采样和不准确的日期，限制了对趋势和具体联系的理解。在这里，我们使用从格陵兰冰芯中进行的亚年分辨率测量得出的公元前 1100 年至公元 800 年期间估计的铅排放量的精确日期记录，以及详细的大气传输模型，表明欧洲每年的铅排放量与历史事件密切相关，包括帝国扩张、战争和大瘟疫。排放与腓尼基人扩张同时增加，在伊比利亚半岛的迦太基和罗马采矿扩张期间加速，在罗马帝国时期达到最大值。排放与战争和政治不稳定同步波动，特别是在罗马共和国时期，在第二和第三个世纪的两次大瘟疫期间急剧下降，持续了>500 年。银币中的银锭也呈下降趋势，反映了古代经济中铅银开采的重要性。我们的结果表明，罗马帝国前两个世纪的经济持续增长，在公元 2 世纪的安东尼瘟疫期间结束。
