GREENLAND ICE EVIDENCE OF HEMISPHERIC LEAD POLLUTION 2-MILLENNIA AGO BY GREEK AND ROMAN CIVILIZATIONS

Analysis of the Greenland ice core covering the period from 3000 to 50 0 years ago-the Greek, Roman, Medieval and Renaissance times-shows tha t lead is present at concentrations four times as great as natural val ues from about 2500 to 1700 years ago (500 B.C. to 300 A.D.). These re sults show that Greek and Roman lead and silver mining and smelting ac tivities polluted the middle troposphere of the Northern Hemisphere on a hemispheric scale two millennia ago, long before the Industrial Rev olution. Cumulative lead fallout to the Greenland Ice Sheet during the se eight centuries was as high as 15 percent of that caused by the mas sive use of lead alkyl additives in gasoline since the 1930s. Pronounc ed lead pollution is also observed during Medieval and Renaissance tim es.