Source characterisation of atmospheric platinum group element deposition into an ombrotrophic peat bog
Journal article, 2004

Platinum, palladium, rhodium, iridium and osmium were found to be enriched relative to their expected natural concentrations in peat samples from Thoreau's Bog, an ombrotrophic peat bog in Concord, Massachusetts. The source of osmium into the bog was determined from its isotopic composition (187Os/188Os). Osmium is composed of 4% lithogenic osmium from atmospheric soil dust, 41% of anthropogenic osmium and 55% of osmium from a non-lithogenic, non anthropogenic source, with rain being a likely candidate for the latter. Significant anthropogenic and rain contributions are also expected for iridium. In contrast, platinum, palladium and rhodium are almost exclusively anthropogenic. The larger enrichments of platinum, palladium and rhodium indicate that automobile catalysts are the source of platinum group elements to Thoreau's bog. The bog is located approximately 300 m from a major road and, therefore, the occurrence of platinum elements is evidence for regional dispersion of these metals. The absence of a clear trend following the introduction of catalysts indicates that platinum group elements are not quantitatively conserved in peat with downward leaching and plants playing an important role in the accumulation of platinum group elements.

atmospheric transport

Platinum group elements

peat bog

Author

Sebastien Rauch

Chalmers, Department of Water Environment Transport, Water Chemistry and Process Technology

Harold F. Hemond

Massachusetts Institute of Technology (MIT)

Bernhard Peucker-Ehrenbrink

Woods Hole Oceanographic Institution

Journal of Environmental Monitoring

1464-0325 (ISSN) 1464-0333 (eISSN)

Vol. 6 4 335-343

Subject Categories

Other Environmental Engineering

DOI

10.1039/b316547g

More information

Latest update

4/11/2018