Modern Pollution Signals in Sediments from Windermere, NW England, Determined by Micro-XRF and Lead Isotope Analysis

Abstract

High resolution geochemical (Itrax micro-XRF and wavelength dispersive XRF) data, radiochronology ( 210 Pb and 137 Cs analyses) and ultra-high precision double-spike lead isotope measurements from lacustrine sediment cores are used in combination with historical research of former mining landscapes to investigate modern pollution signals in sediments from Windermere, the largest lake in the English Lake District. The sediment record suggests that while most element concentrations have been stable, there has been a significant increase since the 1930s in lead, zinc and copper concentrations. Double-spike lead isotope measurements reveal a mixture of natural lead, and three major contributory sources of anthropogenic (industrial) lead, comprising gasoline lead, coal combustion lead (from coal-fired steam ships) and lead derived from Carboniferous Pb-Zn mineralisation (mining activities). A number of up-system sediment traps have limited the amount of mining related heavy metals entering Windermere, and as a result, periods of metal workings do not correlate with peaks in heavy metals. Increases could also be due to flood-induced metal inwash or weathering of bedrock in the catchment. Application of these non-destructive and high precision analytical techniques provides new insights into the pollutant depositional history of Windermere.

X-Ray Core Scanners as an Environmental Forensics Tool: A Case Study of Polluted Harbour Sediment (Augusta Bay, Sicily)

“…In some parts of Europe, an additional peak corresponding to the Chernobyl event (1986) is also seen (e.g. Miller et al 2014Miller et al , 2015 but the impact of Chernobyl is generally claimed to be low in Sicily, but is not necessarily absent (Cundy et al 1998). …”

“…In some cores these may be inferred to have climatological significance (e.g. Miller et al 2014Miller et al , 2015.…”

“…These new analytical tools, of which two proprietary instruments dominate the market (Croudace and Rothwell 2015), have stimulated research output in the environmental sciences (e.g. Croudace et al 2006;Lepland et al 2010;Croudace et al 2012;Miller et al 2014Miller et al , 2015. A particular strength of the Itrax core scanner is its co-registration of radiographic and elemental profiles as well as an optical image.…”

Understanding the impact of millennial to sub-decadal climate and limnological change on the stability of As in lacustrine sediments

“…The use of high-resolution, non-destructive, X-ray fluorescence core scanners (XRF-CS) has become commonplace in the study of paleoenvironments and paleoclimate (Turner et al 2010;Giralt et al 2011;Gregory et al 2015;Profe et al 2016;, sediment provenance (Kujau et al 2010;Hunt et al 2015;Zielhofer et al 2017) and soil and sediment contamination Miller et al 2015;Rodríguez-Germade et al 2015;Lintern et al 2016;Schillereff et al 2016). X-ray fluorescence core scanners are capable of analyzing sediment cores at up to 0.1 mm resolution at < 30 s per interval, offering a major advantage in speed, cost, and resolution over conventional geochemical analysis (ED-or WD-XRF, ICP-MS, INAA).…”

“…Many researchers therefore use XRF-CS data to examine relative changes in elemental concentrations at high resolution in core samples while using conventional geochemical analysis of select samples to accurately determine absolute geochemical values. In environmental studies, XRF-CS is used to identify the timing of impacts, or the spatial and temporal extent of contaminated horizons, which are then verified using conventional geochemical results Miller et al 2015;Rodríguez-Germade et al 2015;Lintern et al 2016;Schillereff et al 2016). If it were possible to obtain more reliable geochemical values using XRF-CS, it would represent an enormous advancement in the ability of researchers to study environmental systems, contamination, and high-resolution climate events in terms of rapidity and cost-effectiveness.…”