History of Atmospheric Lead Deposition Since 12,370 ¹⁴ C yr BP from a Peat Bog, Jura Mountains, Switzerland

Abstract

A continuous record of atmospheric lead since 12,370 carbon-14 years before the present (14C yr BP) is preserved in a Swiss peat bog. Enhanced fluxes caused by climate changes reached their maxima 10, 590 (14)C yr BP (Younger Dryas) and 8230 (14)C yr BP. Soil erosion caused by forest clearing and agricultural tillage increased lead deposition after 5320 (14)C yr BP. Increasing lead/scandium and decreasing lead-206/lead-207 beginning 3000 (14)C yr BP indicate the beginning of lead pollution from mining and smelting, and anthropogenic sources have dominated lead emissions ever since. The greatest lead flux (15.7 milligrams per square meter per year in A.D. 1979) was 1570 times the natural, background value (0.01 milligram per square meter per year from 8030 to 5320 (14)C yr BP).

(Pre-) historic changes in natural and anthropogenic heavy metals deposition inferred from two contrasting Swiss Alpine lakes

“…4 and 5) associated with slight enrichment in metals (e.g., Cu, Pb, and Hg; Figs. 3 and 4) could suggest a local-to regional-scale pollution impact linked to the earliest phase of agriculture in Central Europe and early metallurgy, respectively (Shotyk et al, 1998;Kalis et al, 2003;Turney and Brown, 2007). This assumption might be supported by the charcoal record form Lake Lucerne (Fig.…”

“…In fact, the lithogenic input of crustal trace elements is highly variable due to natural processes variability, as chemical and physical weathering rates influenced by environmental factors (e.g., climate, soils, lake watershed). That is the reason why ombrotrophic peat bogs are preferentially used as long-term archives of atmospheric metal deposition, because they are hydrologically isolated from the influence of ground and surface waters, and their inorganic solids are exclusively supplied by atmospheric deposition (Shotyk et al, 1998;Martinez Cortizas et al, 1999). In opposition to bogs and glaciers, lake sediments do not exclusively reflect past atmospheric emissions, but they are more widespread and can thereby provide worthwhile datasets (Eades et al, 2002;Renberg et al, 2002).…”

Elevated mercury accumulation in a peat bog of the Magellanic Moorlands, Chile (53°S) – an anthropogenic signal from the Southern Hemisphere

“…Pb is enriched in many peat bogs from the Northern Hemisphere due to anthropogenic emissions [37,38], but does not show any visible increase in concentrations or accumulation rates in the GC peat bog during the past 2000 yr (Fig. 2e).…”

Development and refinement of proxy-climate indicators from peats

“…Lead isotope signatures from two mires (Swiss Jura: Shotyk et al, 1998Shotyk et al, , 2001and Galicia: Martinez-Cortizas et al, 2002;Kylander et al, 2005) are compared for the early Holocene in Fig. 5.…”

“…Shotyk et al, 1998), and this formed the basis for ASD reconstruction, encouraging scientists to investigate Holocene time intervals in mires. However, even now, only a few ASD curves have been generated from mires at highresolution, because (i) ASD peaks generally occur during shortterm intervals (at least in Northern Europe), in which very few samples are analysed; (ii) many radiocarbon dates are needed for precise and accurate dating; and (iii) ASD is still an indirect parameter that needs to be cross-checked with the direct quantification of mineral matter in the peat.…”