Ecosystem-wide Transfer of Trace Metal Pollutants from Derelict Metalliferous Mines in the UK

Sartorius, Andrea (2023) Ecosystem-wide Transfer of Trace Metal Pollutants from Derelict Metalliferous Mines in the UK. PhD thesis, University of Nottingham.

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Abstract

Trace metals are persistent elemental pollutants that can be toxic at relatively low concentrations. While trace metals are present in the Earth’s crust at low concentrations, anthropogenic activities, particularly mining, can lead to the accumulation of high concentrations of trace metals. Trace metals can then be inadvertently dispersed throughout the surrounding environments, where they can potentially pose health risks to local fauna. The aim of this project was to assess trace metal contamination across ecosystems, focusing on the distribution of trace metals across landscapes, its transfer into local wildlife, and the potential human health risks.

This project primarily focused on evaluating the ecosystems around two separate derelict metalliferous mine complexes in western Wales. Environmental and animal samples were collected at both sites across three years to assess trace metal contamination. Water, sediment, and soil at the mines and in downstream private properties had elevated Pb, Zn, and, to a lesser extent, Cd and Cu concentrations when compared to nearby control sites. Aquatic invertebrate communities were only slightly less abundant and diverse at the mines than the control sites, but individual invertebrate Pb, Cd, Zn, and Cu body burdens were significantly higher at the mines and private properties than at the control sites. Invertebrate Pb body burdens were particularly high, with approximately one third of the mine invertebrates accumulating Pb to concentrations higher than those found in the surrounding sediments. Rodents at the mines and private properties also had elevated tissue Pb concentrations, potentially indicative of toxicity. Wood mice (Apodemus sylvaticus) at the mines and private properties had significantly higher Pb and Cd tissue concentrations than wood mice collected at the control sites, but appeared to be able to regulate their Zn and Cu tissue concentrations through homeostatic mechanisms.

Humans living near these mine complexes could also potentially be exposed to high concentrations of trace metals. To examine exposure routes, the trace metal contents in eggs produced near a metal mine were assessed with respect to human consumption. The eggs contained high concentrations of Pb, and their regular consumption could pose health risks, particularly in young children. Small-scale studies on vegetables grown near mines indicated that they contained similarly elevated, and potentially toxic, concentrations of Pb.

The relationships between environmental and wildlife trace metal concentrations were also explored across a larger, heterogeneously contaminated landscape. The elemental concentrations of livers from European badgers (Meles meles) collected across the English Midlands were determined and compared with local soil elemental concentrations, established using datasets from the British Geological Survey. While the badgers appeared to regulate essential elements, such as Cr, Cu, K, Mn, and Zn, the liver Ag, As, Cd, and Pb concentrations correlated with local soil concentrations, suggesting environmental accumulation. The badgers with the highest Pb and Cd liver concentrations were consistently found in Derbyshire, a county with a long Pb-mining legacy.

Overall, trace metal pollution can have significant, ecosystem-wide effects long after the original pollution event. Trace metals can be distributed beyond the original pollution site and accumulate at potentially toxic concentrations in environments that appear pristine. They can also transfer into local wildlife at concentrations indicative of toxicity, and humans could be at risk through the ingestion of locally grown food products. These factors make mine site remediation equally important and difficult, since remediation must extend beyond the mine site itself, and must address the potential exposure and health risks for wildlife and humans. As the demand for metals increases in the future, and as extreme weather events caused by climate change become more frequent, trace metal dispersal will continue. It is therefore increasingly imperative that the effects of trace metal pollution on ecosystems are fully understood in order to effectively mitigate their substantial adverse impacts.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Yon, Lisa
Baiker, Kerstin
Bennett, Malcolm
Johnson, Matthew
Young, Scott
Keywords: legacy pollutants, mining, trace metals, wildlife health, macroinvertebrates, lead, mines, pollution, chicken, eggs, human health risks, environmental elemental concentrations, badgers, human-modified environments
Subjects: Q Science > QH Natural history. Biology > QH540 Ecology
Q Science > QL Zoology > QL605 Chordates. Vertebrates
T Technology > TD Environmental technology. Sanitary engineering
Faculties/Schools: UK Campuses > Faculty of Medicine and Health Sciences > School of Veterinary Medicine and Science
Item ID: 73614
Depositing User: Sartorius, Andrea
Date Deposited: 31 Jul 2023 04:41
Last Modified: 31 Jul 2023 04:41
URI: https://eprints.nottingham.ac.uk/id/eprint/73614

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