Anthropogenic lead isotopes in Antarctica
We report the first measurements of Pb isotopes in Antarctic snow, which show that even recent snow containing 2.3 pg/g is highly polluted with anthropogenic Pb. This follows from a comparison of isotope abundances of Pb in surface snow and terrestrial dust extracted from ancient Antarctic ice (Dome C, depth 308 m, approximate age 7,500 a BP), the latter being distinctly more radiogenic. This result is independent of geochemical arguments based on measurements of Al, Na and SO_4. South America is suggested as a likely source of this anthropogenic Pb. The presence of significantly less radiogenic Pb in the snow adjacent to two Antarctic base stations indicates that there is contamination from station emissions, although emission from Australia is an alternative explanation for a site 33 km from Dumont d'Urville.
© 1994 American Geophysical Union. Manuscript Accepted: 7 September 1994; manuscript Received: 19 April 1994. This project was supported by the Australian Research Council, the Ministere de l'Environment (grants 8904 and 92205), the Institut National des Sciences de l'Univers., the University of Grenoble, and the U.S. National Science Foundation (grant DPP 840-3090). Helpful comments on the paper were provided. J. de Laeter, R. Loss, I. Fletcher, R. Delmas and two anonymous reviewers.
Published - grl7947.pdf