Greenland Ice Evidence of Hemispheric Lead Pollution Two Millennia Ago by Greek and Roman Civilizations
Analysis of the Greenland ice core covering the period from 3000 to 500 years ago-the Greek, Roman, Medieval and Renaissance times-shows that lead is present at concentrations four times as great as natural values from about 2500 to 1700 years ago (500 B.C. to 300 A.D.). These results show that Greek and Roman lead and silver mining and smelting activities polluted the middle troposphere of the Northern Hemisphere on a hemispheric scale two millennia ago, long before the Industrial Revolution. Cumulative lead fallout to the Greenland Ice Sheet during these eight centuries was as high as 15 percent of that caused by the massive use of lead alkyl additives in gasoline since the 1930s. Pronounced lead pollution is also observed during Medieval and Renaissance times.
© 1994 American Association for the Advancement of Science. 20 May 1994; accepted 5 August 1994. This work is a contribution of GRIP organized by the European Science Foundation. We thank B. Stauffer and J. P. Steffensen for their very kind assistance in core selection, M. Legrand for the ion chromatography measurements, and R. J. Delmas for his continuous interest and helpful discussions. We thank the national funding agencies and organizations in Belgium, Denmark, France, Germany, Iceland, Italy, Switzerland, and the United Kingdom as well as the XII Directorate of the Commission of European Communities for financial support. Supported by the French Ministry of the Environment (grant 92295), the Institut National des Sciences de l'Univers, and the University of Grenoble.