A synthesis of lead isotopes in two millennia of European air

Four airborne particulate records from ombrotrophic peat bogs in southern Norway, extending back 300 years, have been measured for chronology, lead concentration, and lead isotope composition. Since southern Norway receives an airborne lead signal that accumulates emissions from the European continent, the trend in the four bog records can be used to correlate previously reported measurements from France, Switzerland, England, and Greenland that cover different ranges of time. When these are compiled, the integrated European record that emerges spans the last 2300 years of human influence on lead in the air over Europe and suggests human control of lead in airborne particulates over the entire period. From 365 BC through the first half of the 20th century, lead isotopic compositions in European air have fallen within the range of compositions in European ore bodies. Since 1950, isotopic compositions have been beyond the range in those ore body compositions and have fallen within the array of lead isotope compositions typical of gasoline from western industrial nations (a mixing line between US and Australian lead in gasoline). Thr overlap between the European record and the range in modern European air suggests an average isotopic composition of Pb-206/Pb-207 ca. 1.13 and of Pb-208/(207)pb ca. 2.41 in air over Europe during the last 20 years. (C) 1999 Elsevier Science B.V. All rights reserved.