Dr. Stephen Lofts

My research interests centre around the chemical behaviour of metals and metal-based nanoparticles in soils and surface waters, and how this impacts on their mobility, fate, bioavailability and toxicity. Modelling forms a central component of my work and I have been involved in the development and application of a number of models in this area:

• The Windermere Humic Aqueous Model (WHAM): a model of the equilibrium chemistry of water and soils, including models of the binding of ions to natural organic matter and mineral surfaces;
• WHAM-FTOX: a development of WHAM for modelling the influence of water chemistry on the combined toxicity of protons (i.e. acidity) and metals;
• The Intermediate Dynamic Model for Metals (IDMM): a model of metal dynamics in soils over long time periods (decades/centuries);
• Biotic Ligand modelling: I have taken part in projects to develop Biotic Ligand Models (BLMs) to describe the bioavailability and toxicity of manganese and uranium;
• The IDMM-ag, a model to predict metal fate in agricultural soils and nearby surface waters;
• The NanoFASE model, a catchment scale transport and fate model for manufactured nanomaterials.

I currently play a leading role in CEH's work on the chemistry, fate, impacts and risks of manufactured nanomaterials. I led a core workpackge of NanoFASE (2015-2019) developing a fate and biouptake model for nanomaterials, was CEH PI on ACEnano (2017-2021) to develop a user-oriented toolbox of nanomaterial analytical techniques, and played an expert role in caLIBRAte (2016-2020) assessing the suitability of nanomaterial fate modelling approaches for incorporation into Safe by Design principles. I am currently CEH PI on two ongoing projects: NanoSolveIT (2018-2023), which is developing informatics approaches to modelling nanomaterial impacts, and SAbyNA (2020-2024), which is developing tools and guidance for developing safer nanomaterial and nanomaterial enabled products.

I also lead a pollution-oriented task within the SPEED component of UK-SCAPE (2018-2023), developing and applying a spatial modelling framework for projecting future ecological risks due to metals in GB topsoils.

I joined the former Institute of Freshwater Ecology in 1995 and worked on a number of projects related to metal chemistry modelling and surface water acidification. Since then my work has developed into understanding and predicting the dynamics, bioavailability, toxicity and risks of metals, based on their chemical speciation. Since 2005, my interests have broadened into the dynamics, bioavailability and toxicity of nanomaterials, and into methods for advanced ecological risk assessment of chemicals.