Tracking relevant nanomaterial transformations, exposure, uptake and effects in freshwater and soil systems

Nanomaterials (NM) are very small particles much less than the width of a human hair. They are synthesised to provide different properties from larger forms of the same material and they are now used in a wide range of products. The properties that NMs provide include enhanced strength, an ability to reflect light or to react with other chemicals, and efficient electrical conductance. The value of NM is now very widely recognised and many companies are starting to use them in common consumer products, such as sunscreens and cosmetics, plus industry products, such as fabrics and building materials. This means that small quantities of NMs will reach the wider environment from everyday product use.

A great deal of recent research has gone into assessing the safety of NMs for humans and the environment. Most of these studies have looked at NMs in their newly-manufactured forms. It is increasingly apparent, however, that once NMs are released into the wider environment, they do not stay in their manufactured state - they change or 'transform'. Transformations can affect NM size, charge, their surface coatings and their ability to bind to other things such as soil particles or other chemicals. Transformations occur both during transfer to the environment (e.g. via sewage works) and once NMs reach the wider environment itself (rivers, sediments and soils). It is of huge importance that we understand the transformation processes and environmental fate(s) of NMs as they can affect their toxicity to humans and the environment.

The aim of this project is to study these NM transformations in more detail. We want to better understand whether different types of NMs are transformed in the same or different ways. We will conduct our work with different types of NMs, including those made from silver, titanium dioxide, polystyrene (a type of plastic) and graphene (a type of carbon).

We will first use laboratory methods that mimic the ways that NMs are changed during sewage treatment and in natural waters and soils to create the transformed materials that we will then study. We will test how these new and changed NMs affect a range of common aquatic and soil organisms and contrasting their toxicity in their "pristine" state with that after they have been transformed in the environment for different times. During our tests, we will measure how much of each material is taken up by the organisms into different tissues and whether this affects how they grow and reproduce. We will also measure the activity of different genes that are likely to be affected as organisms take up different NMs. We predict that each NM will be transformed in a way that changes its likelihood to cause harmful effects. Each test will be repeated using different soils and waters typically found across the UK, to determine how transformations vary under different conditions.

Finally, we will build custom-made, large exposure systems ('mesocosms') designed to mimic the rivers into which sewage works discharged and soils upon which sludge is spread, and populate them with a wide range of common UK native plants, invertebrates and fish (in the waters). By following these mesocosms for several months, we can simulate what may actually be happening in real UK environments in terms of the fate and effects of our transformed NMs. We will use the results to improve models able to predict how our transformed NMs will behave and the effects they will have. Taken together, our results should help us to predict the toxicity of NMs to help assure their safety, supporting the growth of the nanotechnology industry into the future. To this latter end we will run and coordinate a UK Nano-Academics & Regulators Platform, and will also present our results through major European Union (NanoSafety Cluster) and worldwide (Organisation for Economic Cooperation and Discussion) policy working groups, as well as to the public, so reaching as wide an audience as possible.

Given the global economic importance of the nanotechnology industry - currently in $ billions worldwide - our findings will be of considerable interest (inter)nationally to a wide range of industries, government regulatory bodies, environmental protection groups and the general public. The major part of our impact activities will be centred on engagement with national and international government regulatory bodies, industry partners, and informing the wider public, as well as on training and incorporating outcomes into higher education.

Our work will benefit regulators and industry by delivering advanced understanding of realistic environment fate and effects of nanomaterials. This knowledge will focus on the mitigation of highly reactive nanomaterial surfaces afforded by environmental transformations, through detailed comparison of the bioaccumulation and toxicity of the pristine and environmentally-transformed forms under realistic chemistries and concentrations. Protocols, methods and models for assessing nanomaterials environmental transformations, and their effects on toxicity will be an outcome of our work. The central dissemination component for this information will be the UK Nano-Academics & Regulators Platform, which has been initiated by UoB and CEH over the last year with support from Defra, EA and CEFAS, and which will be formalised and secured via this project. The 6-monthly meetings of this group over the 3 year project will allow 2-way communication between regulators and academics/industry, facilitating coordination of UK responses to OECD and other international activity, briefing of the academic community of upcoming impact opportunities/research needs, and allowing the academics to relay relevant research outcomes directly to policy makers. This activity will be supplemented if applicable, a joint science-workshop with any other project(s) funded via the Highlight Topic call.

The applicants have considerable experience of commercial engagement via EU consortia, CASE studentships, the NERC-nanoKTN, and KTP and LINK awards with various industry partners. The project team also has a strong track record in actively supporting UK and international governments for screening and testing guidelines, including for nanomaterials, and policy development via a number of routes (e.g. Defra reports, ECHA workshops, OECD test guidelines, European Food Safety Authority, EU Nanosafety cluster). All of these links will provide conduits for knowledge sharing and for creating impact with industry and government bodies.
Results of this work are expected to make a significant scientific impact and major routes for scientific dissemination will be via relevant, high impact ISI scientific journals, and national and international conferences and workshops. The applicants will also disseminate knowledge from this research work via the press (through the CEH & NERC Press Office), to industry and regulators, and into higher education (UoB and UoEx directly, but invited lectures e.g. Oxford nano-summerschool). For wider public disseminations, we will run a two-day public outreach activity, which will include opportunities to view the soil mesocosm experiments, as well as, interactive sessions on the benefits and opportunities of nanomaterials and challenges in detecting nanomaterials in the environment.

The researchers on this project will be provided with the opportunity to develop their awareness of, and skills in, knowledge transfer, designating major roles for the project researchers in the UK Nano-Academics & Regulators Platform, and the outreach activities, as well as in science communication. The participating laboratories have impressive records in employment for their researchers that include permanent positions in academia (both nationally and internationally), and within various industries and government agencies. Our continued development of skilled staff for UK PLC will be a major impact of our project work.