Anthropogenic forcings on the surficial osmium cycle
Artikel i vetenskaplig tidskrift, 2010

Osmium is among the least abundant elements in the Earth’s continental crust. Recent anthropogenic Os contamination of the environment from mining and smelting activities, automotive catalytic converter use, and hospital discharges has been documented. Here we present evidence for anthropogenic overprinting of the natural Os cycle using a ca. 7000-year record of atmospheric Os deposition and isotopic composition from an ombrotrophic peat bog in NW Spain. Preanthropogenic Os accumulation in this area is 0.10 ± 0.04 ng m−2 y−1. The oldest strata showing human influence correspond to early metal mining and processing on the Iberian Peninsula (ca. 4700−2500 cal. BP). Elevated Os accumulation rates are found thereafter with a local maximum of 1.1 ng m−2 y−1 during the Roman occupation of the Iberian Peninsula (ca. 1930 cal. BP) and a further increase starting in 1750 AD with Os accumulation reaching 30 ng m−2 y−1 in the most recent samples. Osmium isotopic composition (187Os/188Os) indicates that recent elevated Os accumulation results from increased input of unradiogenic Os from industrial and automotive sources as well as from enhanced deposition of radiogenic Os through increased fossil fuel combustion and soil erosion. We posit that the rapid increase in catalyst-equipped vehicles, increased fossil fuel combustion, and changes in land-use make the changes observed in NW Spain globally relevant.

Författare

Sebastien Rauch

Chalmers, Bygg- och miljöteknik, Vatten Miljö Teknik

Bernhard Peucker-Ehrenbrink

Woods Hole Oceanographic Institution

Malin E. Kylander

Stockholms universitet

Dominik J. Weiss

The Natural History Museum, London

Imperial College London

Antonio Martinez-Cortizas

Universidade de Santiagode Compostela

David Heslop

Universität Bremen

C. Olid

Universitat Autonoma de Barcelona (UAB)

Tim M. Mighall

University of Aberdeen

Harold F. Hemond

Massachusetts Institute of Technology (MIT)

Environmental Science & Technology

0013-936X (ISSN) 1520-5851 (eISSN)

Vol. 44 3 881-887

Ämneskategorier

Geovetenskap och miljövetenskap

Miljövetenskap

DOI

10.1021/es901887f