Linkage between solid-phase apportionment and bioaccessible arsenic, chromium and lead in soil from Glasgow, Scotland, UK

Abstract

As, Cr, Pb apportionment Glasgow soils Abstract The chemical composition of soil from the Glasgow (UK) urban area was used to identify the controls on the availability of potentially harmful elements (PHE) in soil to humans. Total and bioaccessible concentrations of arsenic, chromium and lead in 27 soil samples, collected from different land uses, were coupled to information on their solid phase partitioning derived from sequential extraction data.The total element concentrations in the soils were in the range <0.1-135 mg kg -1 for As; 65-3680 mg kg -1 for Cr and 126-2160 mg kg -1 for Pb, with bioaccessible concentrations averaging 27, 5 and 27% of the total values respectively. Land use does not appear to be a predictor of contamination, however the history of the contamination is critically important. The CISED (Chemometric Identification of Substrates and Element Distribution) sequential chemical extraction and associated self modelling mixture resolution (SMMR) analysis identified three sample groupings and 16 geochemically distinct phases (substrates). These were related to Fe (n = 3), Al-Si (n = 2), Ca (n = 3), P (n = 1), Mg (n = 3), Mn (n = 1) and easily extractable (n = 3) which was predominantly made up of Na and S. Arsenic, Cr and Pb were respectively found in 9, 10 and 12 of the identified phases with bioaccessible As predominantly associated with easily extractable phases, bioaccessible Cr with the Mg-dominated phases and bioaccessible Pb with both the Mg-dominated and Al-Si phases. Using a combination of the UBM to measure the bioaccessibility of PHE and CISED to identify the geochemical sources has allowed a much better understanding of the complexity of PHE mobility in the Glasgow urban environment. This approach can be applied to other urban environments and soil contamination, and made part of land use planning.

Comparison of two non-specific flow-through sequential extraction approaches to identify the physico-chemical partitioning of potentially harmful elements in a certified reference material

“…Although the CISED procedure does not incorporate simulated biological fluids, and so does not accurately mimic dissolution processes within the human body, it does provide an indication of the physico-chemical components in the test material and how PHE are distributed between them, from which information on relative lability, mobility and bioavailability can be inferred. There are also indications that the output of the CISED can be related to results of the physiologically relevant Unified BARGE Method [57]. Application of the flow through CISED procedure to samples collected during air quality monitoring programmes worldwide could thus provide valuable information on the binding and potential mobility of PHE associated with respirable PM, and hence contribute towards greater understanding of the exposure of urban populations to airborne pollutants.…”

“…Calibration was with respect to solutions freshly-prepared by serial dilution of Agilent Technologies multi-element standard solution 2A. The nuclides quantified were: 27 Al, 137 Ba, 40 Ca, 52 Cr, 53 Cr, 63 Cu, 65 Cu, 56 Fe, 57 Fe, 39 K, 24 Mg, 55 Mn, 23 Na, 60 Ni, 31 P, 206 Pb, 207 Pb, 208 Pb, 28 Si, 29 Si, 88 Sr, 45 Ti, 51 V, 64 Zn, and 66 Zn. The internal standard was 115 In.…”

Investigating the Geochemical Controls on Pb Bioaccessibility in Urban Agricultural Soils to Inform Sustainable Site Management

“…The CISED approach for determining the physico-chemical fractionation of Pb in the test soils has been previously described in a number of studies [13,[23][24][25][26]. The CISED method is designed to identify the distribution and physical form of PTE within the constituents of any given soil and developed to overcome the problems associated with traditional sequential extraction methods [21].…”

The Geoscience Context for Europe's Urban Sustainability – Lessons from Glasgow and Beyond (CUSP): preface

“…The soil paper by Fordyce et al (2018b) reveals that metal concentrations in the urban environment (especially copper, molybdenum, nickel, lead, antimony, zinc and chromium) are typically up to 2.1 times (median values) those of rural soil, as a consequence of urbanisation. The bioaccessibility and mobility of arsenic, chromium and lead in Glasgow soil are evaluated further in the paper by Wragg et al (2018). Similarly, Kim et al (2018) document the extent of persistent organic pollutants (POPs) associated with various land uses in Glasgow and demonstrate that polycyclic aromatic hydrocarbons (PAHs) in the urban soil are largely derived from the combustion of fossil fuels.…”

“…The bioaccessibility and mobility of arsenic, chromium and lead in Glasgow soil are evaluated further in the paper by Wragg et al . (2018). Similarly, Kim et al .…”