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Research article - Peer-reviewed, 2020

Projecting impacts of climate change on metal mobilization at contaminated sites: Controls by the groundwater level

Jarsjo, Jerker; Andersson-Skold, Yvonne; Froberg, Mats; Pietron, Jan; Borgstrom, Robin; Lov, Asa; Kleja, Dan B.

Abstract

Heavy metal and metalloid contamination of topsoils from atmospheric deposition and release from landfills, agriculture, and industries is a widespread problem that is estimated to affect >50% of the Ell's land surface. Influx of contaminants from soil to groundwater and their further downstream spread and impact on drinking water quality constitute a main exposure risk to humans. There is increasing concern that the present contaminant loading of groundwater and surface water systems may be altered, and potentially aggravated, by ongoing climate change, through large-scale impacts on recharge and groundwater levels. We investigated this issue by performing hydrogeological-geochemical model projections of changes in metal(loid) (As and Pb) mobilization in response to possible (climate-driven) future shifts in groundwater level and fluctuation amplitudes. We used observed initial conditions and boundary conditions for contaminated soils in the temperate climate zone. The results showed that relatively modest increases (0.2 m) in average levels of shallow groundwater systems, which may occur in Northern Europe within the coming two decades, can increase mass flows of metals through groundwater by a factor of 2-10. There is a similar risk of increased metal mobilization in regions subject to increased (seasonal or event-scale) amplitude of groundwater levels fluctuations. Neglecting groundwater level dynamics in predictive models can thus lead to considerable and systematic underestimation of metal mobilization and future changes. More generally, our results suggest that the key to quantifying impacts of climate change on metal mobilization is to understand how the contact between groundwater and the highly water-conducting and geochemically heterogeneous topsoil layers will change in the future. (C) 2019 The Authors. Published by Elsevier B.V.

Keywords

Climate change; Metal mobilization; Soil; Groundwater; Mass flow; Health risk

Published in

Science of the Total Environment
2020, volume: 712, article number: 135560
Publisher: ELSEVIER

Authors' information

Jarsjo, Jerker
Stockholm Univ
Andersson-Skold, Yvonne
Swedish Natl Rd and Transport Res Inst VII
Andersson-Skold, Yvonne
Chalmers Univ
Froberg, Mats
SGI
Pietron, Jan
Stockholm Univ
Borgstrom, Robin
Ramboll Sverige AB
Löv, Åsa
Swedish University of Agricultural Sciences, Department of Soil and Environment
Swedish Geotechnical Institute (SGI)
Swedish University of Agricultural Sciences, Department of Soil and Environment

Sustainable Development Goals

SDG6 Clean water
SDG13 Climate action

UKÄ Subject classification

Oceanography, Hydrology, Water Resources
Environmental Sciences

Publication Identifiers

DOI: https://doi.org/10.1016/j.scitotenv.2019.135560

URI (permanent link to this page)

https://res.slu.se/id/publ/104654