Dr Steve Lofts

Current research

Critical limits of inorganic mercury in the terrestrial environment (Biogeochemistry, Topic 3, Objective 3.3).

• Development of a soil-dependent function for the critical limit concentration of mercury in soils

The effects of metal mixtures on earthworms across different soil types (PhD project) (Biogeochemistry, Topic 3, Objective 3.1).

• Generation of laboratory data on the effects of copper-zinc and cadmium-zinc mixtures on the earthworm Eisenia veneta in four soils
• Interpretation of single metal and metal mixture effects by combination of existing bioavailability and mixture models

Integration of research on metals within CEH and preparation of datasets for the CEH Spatial Gateway (Biogeochemistry, Topic 1, Objective 1.2)

• Cataloguing and synthesising CEH data holdings on metals in precipitation, soils, surface waters and biota
• Use of CEH data to answer key research questions on metals in the UK environment:
  • Are metal concentrations in UK rivers declining over time?
  • Do metals in UK soils affect the composition of plant communities at a national scale?
  • Do metals in UK rivers affect the composition of benthic invertebrate communities at a national scale?

Modelling the bioavailability and toxicity of metal and metal oxide nanoparticles to terrestrial and aquatic organisms (Biogeochemistry, Topic 3, Objectives 3.1 and 3.2).

• Working within two major CEH projects, the EU-funded NanoFATE and the NERC/USEPA-funded TINE (see press release here)
• Development of models to explain the bioavailability and toxicity of selected metal and metal oxide nanoparticles to terrestrial and aquatic organisms

Research interests

• Modelling of chemical speciation in terrestrial and aquatic systems
• Consideration of metal speciation and bioavailability in toxic effects and environmental risk assessment
• Understanding and modelling the bioavailability and toxicity of metal and metal oxide nanoparticles to terrestrial and aquatic organisms

Brief CV

• 2006 onwards: Senior Scientific Officer, CEH
• 2001-2006: Higher Scientific Officer, CEH
• 1995-2001: Scientific Officer, CEH (formerly the Institute of Freshwater Ecology)

Research highlights

• Development of SCAMP, a chemical speciation model for metal binding to natural particles (published 1998)
• Development of a methodology to calculate critical limit functions and carry out risk assessment for cationic metals in soils (published 2004, 2005)
• Quantification of the chemical speciation of iron in freshwaters (published 2008)

Selected publications

See also the NERC Open Research Archive

Lofts, S., Criel, P., Ghesquire, U., Janssen, C.R., Lock, K., McGrath, S.P., and eight others. Modelling the effects of copper to soil organisms and processes using the free ion approach: towards a multi-species toxicity model. Environmental Toxicology and Chemistry, submitted.

Lofts, S., Tipping, E., Hamilton-Taylor, J. The Chemical Speciation of Fe(III) in Freshwaters. Aquatic Geochemistry 14, 337-358 (2008).

Lofts, S., Chapman, P.M., Dwyer, R., McLaughlin, M.J., Schoeters, I., Sheppard, S.C., and 33 others. Critical Loads of Metals and Other Trace Elements to Terrestrial Environments. Environmental Science and Technology, 41(18), 6326-6331 (2007).

de Vries, W., Lofts, S., Tipping, E., Meili, M., Groenenberg, J. E., Schütze, G. Impact of Soil Properties on Critical Concentrations f Cadmium, Lead, Copper, Zinc, and Mercury n Soil and Soil Solution in View of Ecotoxicological Effects. Reviews of Environmental Contamination and Toxicology, 191, 47-89 (2007).

Spurgeon, D.J., Lofts, S., Hankard, P.K., Toal, M., McLellan, D., Fishwick, S., Svendsen, C. Effect of pH on metal speciation and resulting metal uptake and toxicity for earthworms. Environmental Toxicology and Chemistry, 25(3), 788-796 (2006).

Lofts, S., Spurgeon, D., Svendsen, C. Fractions Affected and Probabilistic Risk Assessment of Cu, Zn, Cd and Pb in Soils Using the Free Ion Approach. Environmental Science and Technology, 39(21), 8533-8540 (2005).

Lofts, S., Spurgeon, D.J., Svendsen, C., Tipping, E. Deriving Soil Critical Limits for Cu, Zn, Cd, and Pb: A Method Based on Free Ion Concentrations. Environmental Science and Technology, 38, 3623-3631 (2004).

Weng, L.P., Temminghoff, E.J.M., Lofts, S., Tipping, E., Van Riemsdijk, W.H. Complexation with dissolved organic matter and solubility control of heavy metals in a sandy soil. Environmental Science and Technology, 36(22), 4804-4810 (2002).  

Lofts, S., Woof, C., Tipping, E., Clarke, N., Mulder, J. Modelling pH buffering and aluminium solubility in European forest soils. European Journal of Soil Science, 52(2), 189-204 (2001).

Lofts, S., Tipping, E. An assemblage model for cation binding by natural particulate matter. Geochimica et Cosmochimica Acta, 62(15), 2609-2625 (1998).