Dr David Spurgeon: ProjectsMy research focuses on understanding the long-term risks of environmental stressors (especially contaminating chemicals and engineered nanomaterials) mainly for terrestrial ecosystems. The overarching aim of the work is to provide practical tools for risk assessment and modelling of stress induced environmental change. This focus on providing reasonable approaches for ecological risk assessment and management does not, however, preclude us applying innovative methods, when and where these provide greater insight into underlying mechanisms. Main areas of my research are:
Molecular mechanism of toxicity and adaptation to chemical exposureIn a set of NERC-funded and PhD projects conducted with Dr Peter Kille and Dr John Morgan (both Cardiff University), Dr Stephen Sturzenbaum (Kings College, London), Dr Jake Bundy (Imperial College, London) and Professor Mark Blaxter (Edinburgh University) as well as CEH colleague Claus Svendsen and various post-docs and students I have been investigating the mechanism that earthworms and nematodes use to adapt to environmental stress (notably long-term chemical exposure). Extensive sequencing (see www.earthworms.org) has allowed development of a microarray that has been used to investigate gene expression change in response to stress in the earthworm Lumbricus rubellus (as well as the nematode C. elegans). By linking changes in the expression profiles of genes with adverse effects on the physiology and life-cycle and resource allocation modelled using the dynamic energy budget model we have been able to understand the system levels changes that link molecular changes to phenotypic effects.
In a further NERC standard grant, I am also investigating the biochemical basis of phenotypic changes in populations collected from polluted field sites with the aim of established if a metabolomics approach can be used to separate pollution induced metabolic change from “normal” environmentally induced metabolome variation. Finally, I also lead a project combining metabolomics and transcriptomics and Restriction site associated DNA marker (RAD-tag) analysis to identify mechanisms underlying the evolution of long-term trace metal tolerance in earthworms. Environmental impacts of nanotechnology productsIn the EU-funded NanoFATE project I am involved in a series of studies to assess the fate, exposure and resulting toxic effects of a range of engineered nanoparticles (ZnO, Ag, CeO, TiO2) on terrestrial organisms. Work to establish the risk of nanoparticles to soil species is particularly needed because partitioning during effluent treatment and disposal of soil waste provide a key route through with engineered nanoparticles will be released to the environment. The work being done at CEH seeks to identify the key environmental properties governing fate and exposure and the rates and route of nanoparticle uptake and mechanisms of toxic effect. The work mobilises skills in environmental chemistry, ecotoxicology and environmental genomics to understand key processes and provide data and models that can be used for risk assessment. MixturesIn the EU project NOMIRACLE and as part of project for the UK Food Standard Agency (and in subsequent work), I worked to develop new approaches for assessing how effects from pollutant mixtures can be addressed in detail. An important part of this work has been to conduct experiments to test the applicability to existing mixture toxicity concept such as concentration addition and independent action to mixture of chemicals where mode of action is both established and also unknown. The projects have generated advice on how to include the mixture toxicity concept in both site specific and generic risk assessments. Practical approaches for the generic risk analysis of mixtures are currently being developed building on the results of these projects.
Large scale riskI am contributing to projects that are assessing the regional and national scale effects of metal and persistent organic pollution derived from point and diffuse sources. This has included environmental impact assessments at smelter, mines and power station sites and also establishing spatial patterns of PAHs, PCBs and trace metals (Cd, Cr, Cu, Hg, Ni, V, Zn) in soils collected nationwide wide during Countryside Survey 2000 and 2007). These data are being used to assess the large scale risk of diffuse pollution to terrestrial biota. Ecological risk assessmentI was a research contractor and adviser during the development of a tiered framework for assessing ecological risks of contaminated land by the Environment Agency. The main contribution was in the development of the practical approaches that would be used in the latter tiers of the framework. A particular focus was selecting biological tests for use in establishing if contamination has resulted in adverse ecological change at a given site. Further, with CEH colleagues Steve Lofts and Ed Tipping, I have also been working to develop models that link chemical speciation with the species sensitivity distribution concept in support development of more scientifically valid environmental quality standards (http://cldm.defra.gov.uk/). This work has been support by Defra as part of work towards the Convention on Long-Range Transboundary Air Pollution. Chemical risks for human healthIn NERC-funded projects we have been assessing, in collaboration with Imperial College, London, the exposure and potential effects of trace metal released during the operational life of a now-disused industrial facility. Quantifications of metals in relevant environmental samples, such as soil, dust and garden grown vegetables, have been conducted and assessments of the kidney health of people living in the immediate area made. The project has shown that even after a factory has ceased to be operational, the contamination that resulted can remain in the area for some time, leaving people at risk of adverse exposure. The results from my research enable us to collaborate with environmental regulators to deliver better understanding, and to develop tools for sound risk assessment and management, and to guide formulation of effective policies to protect the environment and human health.
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