Reconstructing historical atmospheric mercury deposition in Western Europe using: Misten peat bog cores, Belgium

Abstract

Four sediment cores were collected in 2008 from the Misten ombrotrophic peat bog in the Northern part of the Hautes Fagnes Plateau in Belgium. Total mercury (Hg) concentrations were analyzed to investigate the intra-site variability in atmospheric Hg deposition over the past 1,500 years. Mercury concentrations in the four cores ranged from 16 to 1,100 μg kg(-1), with the maxima between 840 and 1,100 μg kg(-1). A chronological framework was established using radiometric (210)Pb and (14)C dating of two cores (M1 and M4). Pollen horizons from these two cores were correlated with data from two additional cores, providing a consistent dating framework between all the sites. There was good agreement between atmospheric Hg accumulation rates in the four cores over time based on precise age dating and pollen chronosequences. The average Hg accumulation rate before the influence of human activities (from 500 to 1,300 AD) was 1.8 ± 1 μg m(-2)y(-1) (2SD). Maximum Hg accumulation rates ranged from 90 to 200 μg m(-2)y(-1) between 1930 and 1980 AD. During the European-North American Industrial Revolution, the mean Hg accumulation rate exceeded the pre-Industrial values by a factor of 63. Based on comparisons with historical records of anthropogenic activities in Europe and Belgium, the predominant regional anthropogenic sources of Hg during and after the Industrial Revolution were coal burning and smelter Hg emissions. Mercury accumulation rates and chronologies in the Misten cores were consistent with those reported for other European peat records.

Deciphering human–climate interactions in an ombrotrophic peat record: REE, Nd and Pb isotope signatures of dust supplies over the last 2500years (Misten bog, Belgium)

“…For the Industrial Revolution and the Modern period, our REE data confirm the shift in Pb isotope ratios already observed by Allan et al (2013a) in the upper Misten peat record ( Fig. 3a and b).…”

“…The geological substratum is covered by postPaleozoic sediments (clays of alteration, continental and marine sands, loess -Bourgignon, 1953) with some occasional outcrops of Early Cambrian (Revinian) quartzites. In the last 10 years, some geochemical work has been carried out on selected sites from the Hautes Fagnes Plateau (Gaida et al, 1993(Gaida et al, , 1997Kempter, 1996;Renson et al, 2008) and in the Misten in particular (De Vleeschouwer et al, 2007, 2010Allan et al, 2013a). The selected Misten bog is produced by an accumulation of 8 m (estimated by a radar surface prospecting - Wastiaux and Schumacker, 2003) of Holocene peat (De Vleeschouwer et al, 2007).…”

“…The building of the age-depth model is described in Allan et al (2013a). Briefly, it was established by merging cores MIS-08-01W and MIS-08-01b.…”

“…See text for explanation. the upper 1 m of several Misten peat cores emphasize the last millennium changes in vegetation, organic and/or inorganic geochemistry mainly recorded human perturbations (De Vleeschouwer et al, 2009, Allan et al, 2013a.…”

Historical record of atmospheric deposition of metals and d15N in an ombrotrophic karst sinkhole fen, South Carolina, USA

“…Although low background concentrations of metals and an alkaline pH were likely factors in limiting the downward migration of metals after atmospheric deposition, organic matter content was likely the most important factor in preventing migration of Hg, Pb, Zn, Cd, and Cu. Organic matter content in the core ranged from 28 to 69 %, which is much higher than the typical 0.3 to 10 % found in ombrotrophic peats (Allan et al, 2013). Organic matter content in soils has been shown to be a sorbent for Hg (Ravichandran, 2004;He et al, 2007;Nie et al, 2012).…”