TI AND PB CONCENTRATIONS IN RAINWATER-FED BOGS IN EUROPE AS INDICATORS OF PAST ANTHROPOGENIC ACTIVITIES

Chemical and physical analyses of dated ombrotrophic peat cores from 8 European regions were undertaken to determine the effect of forest cl earances, farming, mining and smelting on the composition of atmospher ic aerosols. Elemental concentrations in peat were determined using XR F and the mean concentrations of Ti and Pb in peat as well as Pb enric hment factors (Pb EFs) were calculated for each region and for differe nt time periods (Roman Times, Dark Ages, Middle Ages, modem times). Th e results show that the concentration of Ti, Pb and the calculated Pb EFs closely follow changes in land use history extending back thousand s of years. Concentrations of Ti, for example, reflect changing soil d ust inputs in response to forest clearing and agriculture. Lead emissi ons are characterized by considerable Continental-scale variations: el evated concentrations and EFs during the Roman Period at most sites, v ery high concentrations and EFs in the Hart Mountains during the Medie val period, and elevated to high concentrations and EFs during modern times at all sites. The findings indicate that peat cores from ombrotr ophic bogs are useful not only for quantifying temporal changes in met al emissions, but also for identifying spatial variations on scales ra nging from regional to global.