2000 YEARS OF ATMOSPHERIC ARSENIC, ANTIMONY, AND LEAD DEPOSITION RECORDED IN AN OMBROTROPHIC PEAT BOG PROFILE, JURA MOUNTAINS, SWITZERLAND

A peat core from a Swiss bog reveals significant enrichments of As, Sb , and Ph extending back to Roman times, indicating that the anthropoge nic fluxes of these metals have exceeded the natural fluxes for more t han 2000 years. The isotopic composition of Ph provides no evidence of vertical downward Pb migration, suggesting that the bog has faithfull y preserved the historical record of atmospheric Ph deposition, Age da ting using Pb-210 (verified independently using pollen markers) provid es the chronology of changing metal concentrations during the past 150 years. Present day enrichment factors (relative to the metal/Sc ratio s of typical crustal rocks) are of the order of 20 times (As), 70 (Sb) , and 130 (Pb). Given the potential toxicity of As and Sb, these new f indings suggest that the environmental significance of these, and perh aps other less common trace elements, deserve more attention.