Lead in the European Atmosphere from the Ortles Ice Cores, the Last 7000 Years

Four ice cores were recovered in 2011 from the Alto dell'Ortles glacier (3859 m, South Tyrol, Italy). This study presents the results from the analyses of the ice cores #1 (73.5 m) and #3 (74.83 m) performed at the University of Venice (Department of Environmental Sciences, Informatics and Statistics, DAIS) and at The Ohio State University (Byrd Polar and Climate Research Center, BPCRC) that cover the last 3000 and 7000 years, respectively. Core#1 and #3 were analyzed by Continuous Flow Analyses (CFA). The samples from core#1 were also measured discreetly. Trace elements analyses performed at DAIS were performed by using an ICP-MS (Agilent 7500), whereas those performed at the BPCRC by means of a ICP-SF-MS (Element2, Thermo).The Ortles cores provide a detailed Lead contamination reconstruction of the past European atmosphere. A first Lead enrichment was found during the time of the Roman Empire, due to intense Lead and Silver mining activities. Afterwards Lead levels remained low except during the periods 1380- 1500 AD and 1580-1680 AD, revealing an enhancement in European Silver mining activities. The highest Lead levels were determined during the last century, starting in the 1920s, mostly caused by leaded gasoline. A comparison with other local archives corroborates the results of the Ortles ice cores. A comprehensive comparison with most of the available lead reconstructions allows obtaining a worldwide perspective of atmospheric contamination from this toxic metal.