A comparison of control banding tools for nanomaterials.

Control banding (CB) is a useful approach to evaluate and control the risk of exposure to nanomaterials (NM) due to uncertainty surrounding their toxicity and challenges associated with their measurement. Four CB tools specifically developed for NMs (NanoSafer, Stoffenmanager-Nano, NanoTool, and the Precautionary matrix) have been evaluated for their changes to differences in hazard and exposure input data. The hazard and exposure classification were also compared with experimental data. The tools provided different hazard and emission/exposure outputs when compared with each other and with experimental data. For some of the tools the information required to estimate the hazard is not always available in the Safety Data Sheet and it requires expert judgement. The tools have the potential to be valuable starting points to assess areas of high priority, although outputs should be interpreted with care. Further work should be done to improve their estimates, especially the inclusion of modifiers that account for the effectiveness of the ventilation and the effect of high temperatures during the process.

Foresight Study on the Risk Governance of New Technologies: The Case of Nanotechnology.

Technology-led innovation represents an important driver of European economic and industrial competitiveness and offers solutions to societal challenges. In order to facilitate responsible innovation and public acceptance, a need exists to identify and implement oversight approaches focused on the effective risk governance of emerging technologies. This article describes a foresight study on the governance of new technologies, using nanotechnology as a case example. Following a mapping of the governance landscape, four plausible foresight scenarios were developed, capturing critical uncertainties for nanotechnology governance. Key governance elements were then stress tested within these scenarios to see how well they might perform in a range of possible futures and to inform identification of the strengths, weaknesses, opportunities, and threats for nanotechnology governance in Europe. Based on the study outcomes, recommendations are proposed regarding the development of governance associated with the responsible development of new technologies.

How important is drinking water exposure for the risks of engineered nanoparticles to consumers?

This study explored the potential for engineered nanoparticles (ENPs) to contaminate the UK drinking water supplies and established the significance of the drinking water exposure route compared to other routes of human exposure. A review of the occurrence and quantities of ENPs in different product types on the UK market as well as release scenarios, their possible fate and behaviour in raw water and during drinking water treatment was performed. Based on the available data, all the ENPs which are likely to reach water sources were identified and categorized. Worst case concentrations of ENPs in raw water and treated drinking water, using a simple exposure model, were estimated and then qualitatively compared to available estimates for human exposure through other routes. A range of metal, metal oxide and organic-based ENPs were identified that have the potential to contaminate drinking waters. Worst case predicted concentrations in drinking waters were in the low- to sub-µg/l range and more realistic estimates were tens of ng/l or less. For the majority of product types, human exposure via drinking water was predicted to be less important than exposure via other routes. The exceptions were some clothing materials, paints and coatings and cleaning products containing Ag, Al, TiO2, Fe2O3 ENPs and carbon-based materials.

ITS-NANO--prioritising nanosafety research to develop a stakeholder driven intelligent testing strategy.

BACKGROUND: To assess the risk of all nanomaterials (NMs) on a case-by-case basis is challenging in terms of financial, ethical and time resources. Instead a more intelligent approach to knowledge gain and risk assessment is required. METHODS: A framework of future research priorities was developed from the accorded opinion of experts covering all major stake holder groups (government, industry, academia, funders and NGOs). It recognises and stresses the major topics of physicochemical characterisation, exposure identification, hazard identification and modelling approaches as key components of the current and future risk assessment of NMs. RESULTS: The framework for future research has been developed from the opinions of over 80 stakeholders, that describes the research priorities for effective development of an intelligent testing strategy (ITS) to allow risk evaluation of NMs. In this context, an ITS is a process that allows the risks of NMs to be assessed accurately, effectively and efficiently, thereby reducing the need to test NMs on a case-by-case basis.For each of the major topics of physicochemical characterisation, exposure identification, hazard identification and modelling, key-priority research areas are described via a series of stepping stones, or hexagon diagrams structured into a time perspective. Importantly, this framework is flexible, allowing individual stakeholders to identify where their own activities and expertise are positioned within the prioritisation pathway and furthermore to identify how they can effectively contribute and structure their work accordingly. In other words, the prioritisation hexagon diagrams provide a tool that individual stakeholders can adapt to meet their own particular needs and to deliver an ITS for NMs risk assessment. Such an approach would, over time, reduce the need for testing by increasing the reliability and sophistication of in silico approaches.The manuscript includes an appraisal of how this framework relates to the current risk assessment approaches and how future risk assessment could adapt to accommodate these new approaches. A full report is available in electronic format (pdf) at http://www.nano.hw.ac.uk/research-projects/itsnano.html. CONCLUSION: ITS-NANO has delivered a detailed, stakeholder driven and flexible research prioritisation (or strategy) tool, which identifies specific research needs, suggests connections between areas, and frames this in a time-perspective.

Quantum dot cytotoxicity in vitro: an investigation into the cytotoxic effects of a series of different surface chemistries and their core/shell materials.

The aim of this study was to assess the effects of a series of different surface coated quantum dots (QDs) (organic, carboxylated [COOH] and amino [NH2] polytethylene glycol [PEG]) on J774.A1 macrophage cell viability and to further determine which part of the QDs cause such toxicity. Cytotoxic examination (MTT assay and LDH release) showed organic QDs to induce significant cytotoxicity up to 48 h, even at a low particle concentration (20 nM), whilst both COOH and NH2 (PEG) QDs caused reduced cell viability and cell membrane permeability after 24 and 48 h exposure at 80 nM. Subsequent analysis of the elements that constitute the QD core, core/shell and (organic QD) surface coating showed that the surface coating drives QD toxicity. Elemental analysis (ICP-AES) after 48 h, however, also observed a release of Cd from organic QDs. In conclusion, both the specific surface coating and core material can have a significant impact on QD toxicity.

Review of carbon nanotubes toxicity and exposure--appraisal of human health risk assessment based on open literature.

Carbon nanotubes (CNTs) possess many unique electronic and mechanical properties and are thus interesting for numerous novel industrial and biomedical applications. As the level of production and use of these materials increases, so too does the potential risk to human health. This study aims to investigate the feasibility and challenges associated with conducting a human health risk assessment for carbon nanotubes based on the open literature, utilising an approach similar to that of a classical regulatory risk assessment. Results indicate that the main risks for humans arise from chronic occupational inhalation, especially during activities involving high CNT release and uncontrolled exposure. It is not yet possible to draw definitive conclusions with regards the potential risk for long, straight multi-walled carbon nanotubes to pose a similar risk as asbestos by inducing mesothelioma. The genotoxic potential of CNTs is currently inconclusive and could be either primary or secondary. Possible systemic effects of CNTs would be either dependent on absorption and distribution of CNTs to sensitive organs or could be induced through the release of inflammatory mediators. In conclusion, gaps in the data set in relation to both exposure and hazard do not allow any definite conclusions suitable for regulatory decision-making. In order to enable a full human health risk assessment, future work should focus on the generation of reliable occupational, environmental and consumer exposure data. Data on toxicokinetics and studies investigating effects of chronic exposure under conditions relevant for human exposure should also be prioritised.

Review of fullerene toxicity and exposure--appraisal of a human health risk assessment, based on open literature.

Fullerenes have gained considerable attention due to their anti-oxidant and radical scavenging properties. Their current applications include targeted drug delivery, energy application, polymer modifications and cosmetic products. The production of fullerenes and their use in consumer products is expected to increase in future. This study aims to investigate the feasibility and challenges associated with conducting a human health risk assessment for fullerenes based on the open literature, utilising an approach similar to that of a classical regulatory risk assessment. Available data relates to different types of fullerenes (with varying size, surface chemistry, solubility, aggregation/agglomeration) and care should therefore be taken when drawing general conclusions across the parameters. Pristine fullerenes have shown low toxicity and there is probably no risks expected for humans exposed to fullerenes in the workplace under good hygiene conditions. The main concern for consumers is exposure via direct dermal application of fullerenes present in cosmetics. Available studies do not indicate a short term risk from the tested fullerene types, however no extrapolation to all fullerene types and to chronic exposure can be made. In conclusion, the current dataset on fullerenes in relation to both, human exposure and hazard is limited and does not allow reaching any definite conclusions suitable for regulatory decision making. Main future work should focus on generating occupational and consumer exposure data, as well as suitable data on toxicokinetics and potential toxic effects following repeated inhalation and dermal exposure allowing to determine a NOAEL. It seems also relevant to clarify whether certain fullerene types may potentially induce genotoxic and/or carcinogenic effects via physiologically relevant routes.

Nanomaterials for environmental studies: classification, reference material issues, and strategies for physico-chemical characterisation.

NanoImpactNet is a European Commission Framework Programme 7 (FP7) funded project that provides a forum for the discussion of current opinions on nanomaterials in relation to human and environmental issues. In September 2008, in Zurich, a NanoImpactNet environmental workshop focused on three key questions: 1. What properties should be characterised for nanomaterials used in environmental and ecotoxicology studies? 2. What reference materials should be developed for use in environmental and ecotoxicological studies? 3. Is it possible to group different nanomaterials into categories for consideration in environmental studies? Such questions have been, at least partially, addressed by other projects/workshops especially in relation to human health effects. Such projects provide a useful basis on which this workshop was based, but in this particular case these questions were reformulated in order to focus specifically on environmental studies. The workshop participants, through a series of discussion and reflection sessions, generated the conclusions listed below. The physicochemical characterisation information identified as important for environmental studies included measures of aggregation/agglomeration/dispersability, size, dissolution (solubility), surface area, surface charge, surface chemistry/composition, with the assumption that chemical composition would already be known. There is a need to have test materials for ecotoxicology, and several substances are potentially useful, including TiO(2) nanoparticles, polystyrene beads labelled with fluorescent dyes, and silver nanoparticles. Some of these test materials could then be developed into certified reference materials over time. No clear consensus was reached regarding the classification of nanomaterials into categories to aid environmental studies, except that a chemistry-based classification system was a reasonable starting point, with some modifications. It was suggested, that additional work may be required to derive criteria that can be used to generate such categories, that would also include aspects of the material structure and physical behaviour.

Investigation of accidental secondary exposure to CS agent.

We report on an unusual exposure to o-chlorobenzylidene malononitrile (CS agent) following its use to detect unauthorized stowaways aboard a vehicle, and the subsequent handling of the cargo delivered to retail stores across Scotland. Twenty-one staff in 16 retail stores across Scotland experienced symptoms including itching and running eyes, rhinorhoea, a burning sensation on the face and hands, and a burning throat, following the furniture deliveries. A survey was conducted to assess the extent of exposure to the contaminated furniture and the scale of illness associated with exposure. Experiencing symptoms was significantly associated with having contact with the furniture or packaging (chi(2) = 10.5, p < 0.001). This incident demonstrates the risk of inadvertent secondary exposure and subsequent acute symptoms from contact with residual CS agent when sprayed in the confined spaces of haulage vehicles.