More information? mallan@doct.ulg.ac.be nathalie.fagel@ulg.ac.be ages.ulg.ac.be

1. Atmospheric deposition of trace metals and metalloids recorded by Misten peat (Hautes-Fagnes, Belgium) during the Industrial Revolution Mohammed Allan a, Gaël Le Roux b, c, François De Vleeschouwer b, c, Nathalie Fagel a a AGEs, Département de Géologie, Université de Liège, Allée du 6 Août, B18 Sart Tilman B-4000, Liège, Belgium; b Université de Toulouse ; INP, UPS; EcoLab; ENSAT, Avenue de l’Agrobiopole, 31326 Castanet Tolosan, France ; c CNRS; EcoLab; 31326 Castanet Tolosan, France Material Aims Localisation To determine the extent of atmospheric TM contamination, it is necessary to identify the main past and present sources of TM emissions. Peat bogs have a great potential to record anthropogenic inputs via their constituting mosses, because they draw their nutrients only from the atmosphere. We determine precisely the chemical depth-profiles of V, Cr, Co, Ni, Cu, Zn, As, Cd, Sb, Pb, and Pb isotopes, in a high resolution peat-sampled sequence. We investigate possible mobility of TM by comparing some elements (Pb, Cu, Ni, Cr, V, and Zn) with another high-resolution peat sequence. By coupling cluster analyses and Pb isotopes, we identify TM relationships and sources since the last 200 years. We finally compare our results with previous investigation in a low resolution peat core focused on Pb in the same area (De Vleeschouwer et al., 2007) and in Western Europe. • Peat cores were collected in 2008. • Ages of top layers were calculated using 210Pb decay and the CRS model (Appleby, 2001). 14C measurements were performed with NEC 0.5MV Pelletron spectrometer in Poznan Radiocarbon Laboratory, Poland. An age model was obtained by combining the results with the 210Pb.. • The concentrations of major and trace elements were measured by ICP-MS, at the Paul Sabatier University-Toulouse, France. • Lead isotope ratios were measured on a MC-ICP-MS (DSTE, University of Brussels). 206 Depth (cm) Results and Interpretation Profiles of major and trace element concentration (µg g-1), 206Pb/207Pb ratios, and bulk density (g.cm-3) versus depth. Black line corresponds to TM concentration measured in 01W core and gray line some TM concentration measured in 06W core Calculated total atmospheric fluxes (in mg. m-2. yr-1) of Pb, Cu, Sb, Ni, As, Cr, V, Co, Cd and Zn for the Misten peat bog core 01W. Dendogram for AR of TM, Ti and Al in the Misten peat bog for different periods. a) AR of TM, Ti and Al measured between 1400 and 1700 AD, b) AR of TM, Ti and Al measured over the Industrial Revolution, c) AR of TM, Ti and Al measured for the interval between 1990 and 2008, d) TM emissions measured in Walloon region between 1990 and 2008. Acknowledgements More information? mallan@doct.ulg.ac.be nathalie.fagel@ulg.ac.be www.ages.ulg.ac.be • The Misten peat bog is heavily polluted in metals and metalloids • The main trends in TM concentration profiles suggest common sources of these elements and support the view that TM (except Zn and Cd) are immobile in peat. Other TM are highly enriched in peat surface layers and may indicate that they are carried on by large unweathered particles. • The lead isotope data and statistic methods were used to identify the independent historical TM sources. • Industrial Revolution is characterized by different sources such as regional Pb ore mining, coal combustion and steel industry (“Sillon Sambre et Meuse”), which declined during the sixties-seventies. • Pb isotopes in the top layers fingerprint a secondary recent source, which remains to be identified. Conclusion We thank the Walloon Region as well as the F.N.R.S for funding this project. We also thank all personnel who participated in this project.