Quantifying the physcio-chemical characteristics of cerium oxide nanoparticles; a preliminary for ecotoxicological investigations

Manufactured nanoparticles (NPs) can be defined as material purposefully produced by human activity which is between 1 and 100 nm (1 nm is a thousand millionth of a metre). In the last 3-5 years, there has been intense interest and research in the environmental effects of NPs because of our limited knowledge of their harmful effects in the environment and due to the large and increasing scale of the nanotechnology industry. The NERC has recognized this by making Environmental Nanoscience one of seven key areas of concern in its Environment, Pollution and Human Health theme. In addition, this concern has been highlighted by reports from many learned bodies including the Royal Society and Royal Academy of Engineering report (http://www.nanotec.org.uk/finalReport.htm) published in 2004. Worldwide government R&D spending in 2005 on nanotechnology was estimated as ca US$ 4100 million (Roco, 2005) with equivalent sums coming from private sources, and which is increasing year on year. Global markets have been estimated as ca £2 trillion by 2014 and nanotechnology products are now available in an enormous range of consumer goods (fabrics, cosmetics etc) and are used in a range of commercial and industrial processes (such as environmental remediation). It is clear that nanoscience and nanotechnology are immensely important activities, both economically and socially, and will become more so in the near future. Nevertheless, it is also clear that given the scale of the increasing usage and the potential toxicity of these NPs, adverse environmental and human health effects are likely. Cerium oxide is one type of nanoparticle which is used in a range of products and processes and which is potentially beneficial or harmful in the environment but our knowledge of what parameters make them harmful or beneficial is poor. This project will produce tightly controlled NPs which will be characterised thoroughly in terms of their physical and chemical characteristics including size, oxidation state, aggregation behaviour, surface properties. All of these parameters may affect their environmental effects. The NPs will be available for future projects investigating the ecotoxicological effects of NPs in bacteria, algae, invertebrates and fish, but not performed directly in this project.