Evaluation and conclusions. The objectives presented in the deliverable description aiming to develop and validate SOPs for quantitative TEM analysis of MNM were reached. SOPs for quantitative TEM analysis of MNM were developed. These SOPs were validated by application on a series of nanomaterials of various types and sizes, by intra-laboratory and inter- laboratory validation based on the estimation of the measurement uncertainties. These SOPS allow to estimate the minimal external dimension of NM such that the EC definition for NM can be implemented for a wide selection of colloidal and aggregated fractal-like nanomaterials with known measurement uncertainties. Further a large panel of size and shape measurands with measurement uncertainties were determined for these materials, resulting in a detailed characterization required for e.g. risk analyses. Figure 21 gives a schematic overview of the steps included in the developed, complete TEM analysis to measure the size and shape of the particles of a MNM in the framework of implementation of the nanomaterial definition and characterisation, for risk analysis. Figure 21 Schematic overview of the steps included in a complete TEM analysis to measure the size and shape of the particles of a MNM. • The SOP to prepare a TEM specimen suitable for qualitative and quantitative analysis from a dispersed NM ensures that the NM samples are suitable for TEM imaging and analysis. The examined materials were evenly distributed over the grids and the fraction of the attached NM represents the dispersed NM optimally. • The SOP to record a set of calibrated transmission electron micrographs showing NM that are representative for the NM on the EM grid ensures that the number of particles and the magnification of the micrographs are suitable for subsequent descriptive and quantitative image analyses. • The method for characterizing the primary particles and aggregates of a NM by describing their physical properties based on TEM micrographs provides a step-by-xxxx xxxxx for the descriptive characterization of nanomaterials. • The SOPs to analyze the 2D properties of the primary and aggregated/agglomerated particles on EM micrographs ensure that the primary particles are detected and that size and shape measurands are determined quantitatively. A modified version allows to measure the size and shape properties of the aggregates/agglomerates. • Data were analyzed and represented according to relevant ISO-norms. The EM-based results were related to the resu...
Evaluation and conclusions. 2.5.1. Task 2.4 e) Procedures for quantification of MNM exposure and fate in dispersions for ecotoxicological studies Currently, an adequate interpretation of data generated in aquatic ecotoxicity studies is often limited owing to a lack of an appropriate procedure for the physicochemical characterisation and quantification of test MNM being implemented in such studies. The developed NANoREG ECOTOX Dispersion Characterisation TGD provides a framework for aquatic ecotoxicologists to generate the necessary physicochemical characterisation data to enable improved interpretation of results and also for improved read across between data generated in different studies. Importantly, the TGD is designed in such a way as to try and minimise the amount of MNM dispersion characterisation necessary to achieve this goal. The TGD is best employed in conjunction with other relevant SOPs generated within NANoREG WP2 for preparing and characterising MNM dispersions in ecotoxicity studies in order to achieve reproducible data within in ecotoxicity tests. The TGD has been developed in NANoREG WP2 and implemented in NANoREG WP4 for evaluation purposes. Application of the TGD developed in NANoREG WP2 within the aquatic ecotoxicity studies completed as part of NANoREG WP4 highlights clearly that there is a need for including and conducting detailed physicochemical characterisation of MNM dispersion exposures throughout the duration of an ecotoxicity test. The TGD provides a framework to better understand MNM behaviour and fate in ecotoxicological studies. We believe the developed TGD enables a clearer and more reproducible decision making process for MNM characterisation in aquatic ecotoxicity tests. Through the implementation of the TGD in aquatic ecotoxicity tests conducted in NANoREG WP4, we were able to conduct an internal evaluation. It was found that a number of key factors can significantly influence the MNM exposure organisms undergo in aquatic ecotoxicity tests: • MNM type (inherent physicochemical properties) • MNM exposure dispersion concentration (all toxicity tests employ an exposure concentration range in order to establish an effect concentration for the test item) • Media type media type is typical specific to individual standard tests/organisms and can vary considerably in composition) • Ecotoxicity test duration (time was found to be a significant factor in controlling the exposure dispersion conditions) It was also determined through the evaluation process th...
Evaluation and conclusions. A suite of NM has been established. All selected NANoREG MNM are now available for order. This concludes D2.1.
Evaluation and conclusions. Based on an extensive literature review and dialogue workshops with nanosafety researchers, this deliverable has created an inventory of the technical and social challenges that are currently inhibiting reliable safety assessment of manufactured nanomaterials, presented a characterisation of different types of uncertainty important in science for policy, and surveyed the potential of both new approaches to scientific research and to management and governance as ways to overcome the identified challenges and move forward in the face of uncertainties. In the review of two new approaches to safety testing of MNMs – high throughput screening and organ-on-a-chip – the deliverable concludes that although these approaches offer significant benefits such as a potential reduction of costs, time and animal use in safety testing, technical challenges and limitations remain concerning issues such as the regulatory acceptability of such approaches, the added value of the knowledge generated, and the relationship to real world scenarios. Having characterised various forms of uncertainty that are particularly relevant in safety assessment and that new technical approaches to safety testing cannot eliminate, the deliverable then provided a critical review of two new governance approaches seeking to manage complex risks in the face of uncertainty – Safe-by-Design and Responsible Research and Innovation. After highlighting the potential benefits and challenges associated with both approaches, this deliverable presented a way in which RRI and SbD could be combined within a stage-gate model of innovation for maximum benefit and a comprehensive assessment. This combination represents a unique contribution to the SbD stage gate model being developed within NANoREG. By including a broader range of actors and issues for consideration, it aims to enhance the potential for safe, sustainable and responsible innovation using MNMs, as called for by the European Commission. Even though challenges remain for the operationalisation and practical implementation of these new approaches to governance, the work in this deliverable offers a useful overview and critical review of the approaches and thereby a step forward towards the safe and responsible development of MNMs in the face of various forms of uncertainty. Finally this deliverable contributes in a distinctive way to the NANoREG project by offering an overview of how the challenges facing the safety assessment of MNMs that have been ...
Evaluation and conclusions. Concluding remarks are in chapter 7.
Evaluation and conclusions. Generated data suggest a lack of serious embryotoxicity after oral and pulmonary exposure to carbon nanotubes and cerium dioxide, respectively; the observed subtle effects observed in the mother (i.e. a decreased rate of weight gaining during pregnancy) do not seem to affect the outcome of pregnancy. However, the pathophysiologic pathways underlying this phenomenon need to be explored. It remains also to be determined whether the same effect may be observed after oral and pulmonary exposure to other nanoparticles. The lack of toxic effects for the foetus after oral exposure to carbon nanotubes has been reported previously (Xxx et al 2011) at even much higher doses than those used in this project. We, however, tested for the first time the effect on the entire duration of pregnancy, starting exposure immediately after fertilization, whereas in the above-mentioned study, exposure started after the sixth day, so leaving unexplored the very early stages. We, therefore, believe that additional substantial information on the safety of exposure to carbon nanotubes during pregnancy has been added by our study. We are unaware of any data regarding the possible reproductive effects of pulmonary exposure to cerium dioxide; so our findings regarding the safety of this nanomaterial in pregnancy represent important information for exposure of pregnant women to this nanoparticle in occupational and environmental settings. From the perspective of regulators and policy makers, our data imply that unintended oral exposure to CNTs and pulmonary exposure to cerium oxide nanoparticles at doses which can be realistically expected in occupational and environmental settings should not pose peculiar risk to pregnant women. Unintended high dose (accidental) oral exposure to carbon nanotubes might have detrimental effects on gestation, and therefore close monitoring of maternal and foetal parameters should be performed.
Evaluation and conclusions. Inhalation exposure assessment of MNM using measurements is challenging because of the temporal and spatial variations nanoparticles may undergo from emission until they reach the breathing zone of the worker. These changes affect the particle number and mass concentration as well as the PSD and the assessment requires the use or personal monitors. However, because of the different physical principles used to measure particles in the nano and micron rage there is not a single monitor that covers from the nano range up to the respirable fraction, which is the recommended health relevant fraction that should be covered for risk assessment. Exposure modelling, particularly when combined with exposure measurement data, can be a useful tool for risk assessment and risk management by enabling prediction of exposures using information about emission and the conditions of the workplace that affect particle dynamics. This deliverable has reviewed and tested a number of the exposure models that can be used for MNM either for qualitative or quantitative risk assessment. The qualitative models are simple and straightforward to use and they have been made available through easy to use web tools. However, a literature of their performance revealed that the models have not actually been demonstrated with field data and the few studies that have looked at their performance acknowledge that the outputs have to be considered with care. The dataset collected in a chamber room and presented in D3.4 have allowed us to investigate the performance of the new I-Nano tool in terms of temporal and spatial resolution (NF and various FF positions) under different source emission and ventilation conditions. The measurements collected at multiple FF points have allowed us to estimate how different the FF concentrations at the different locations differed from each other and whether the single modelled FF concentration is justified for using in these scenarios. The different source emission types (constant and burst/spike) as well as the different ventilation conditions allowed us to explore the sensitivity of these models to changes in those variables and adds information on Q11 on the determinants of occupational exposure and Q12 on the how data should be collected for model input. The predictions from the I-Nano two box model compared well with the measured data collected in the ‘purpose build’ simulation study. Concentrations in some of the FF locations were overestimated for some s...
Evaluation and conclusions. Inhalation is considered the gold standard for dosing the respiratory tract. The major advantage of inhalation exposure is that it mimics human pulmonary exposure by distributing the inhaled material throughout the whole respiratory tract in a physiological way over time. The work was done along two axes: - A literature review conducted in an objective to propose recommendations in terms of aerosol measurement strategy. The first objective was conducted mainly by LNE and INRS. - Experimental work with the aim to characterize different test aerosols using different generation methods to be used for inhalation studies. The second objective was conducted by the four partners INRS, LNE, LTH and NRCWE. The results clearly show several things: - For dry-based method, where mechanical forces are added to dry nanomaterial powder, and the resulting separated particles are entrained in air, the test aerosols obtained cover the particle size range from about few tens of nanometers up to several micrometers. Test aerosols are mainly composed or aggregates and/or agglomerates that composed the nanomaterial powder. The conditions required for inhalation studies (stability, repeatability, level of concentrations) are sometimes difficult to obtain, but possible. Few generation devices are commercially available. Nevertheless, it is necessary to carry out preliminary tests in order to ascertain the performances of the chosen devices and their suitability for the inhalation facility. The dry-based method, apparently easy to implement, actually requires a good level of know-how and expertise in terms of generation and characterization. - For direct-synthesis method, where airborne nanoparticles are synthesized in the gas phase and delivered to inhalation xxxxxxxx as they remain suspended, the test aerosols obtained cover the particle size range from about few nanometers up to several hundred of nanometers. Higher concentrations in number can be obtained with this method. Also stability and repeatability is generally very good. Very few generation devices are commercially available. The development of such home-made generation system is a long-term task requiring a high level of expertise in terms of generation and aerosol characterization. Altogether, the work carried out show that the generation and the characterization of the test aerosols for inhalation studies is an essential step but remains complex if one wishes to obtain robust results.
Evaluation and conclusions. Notwithstanding the difficulties the T1.3 partners faced in collecting the scientific information from within NANoREG to compile elements of answers to the questions of regulatory relevance (D1.1), this deliverable, which was preceded by the interim overview of D1.3, shows that:
Evaluation and conclusions. The NANoREG data platform is a complex ecosystem of components serving various purposes, as described in section 2 above. It was conceptually ready within a few months after the project start. The immediate choice of a free and ready to use CMS – CIRCABC – proved crucially beneficial to the implementation of the project. It also served as (temporary) repository of project experimental data. The development of the NANoREG database, the main component of the platform, and the related handling of experimental data required much more work from T1.5 and NANoREG partners than expected. The NANoREG management understood within the first year that a well-thought data management strategy inside the project was essential. T1.5 advocated the development of the 'ISA-TAB-Nano templates'. This proved to be a wise choice. That idea based in ISA-TAB-Nano was later used also by other projects and initiatives in the EU and beyond. The roadmap to implement the strategy was ready by November 2014. It was followed by T1.5 until the end of the project, leading to the population of the NANoREG database with well-structured data. That NANoREG experimental dataset, thanks to its good structure, is being exported to the NANoREG- eNanoMapper database, with the potential of full exploitation of its value by other EU-funded projects and possibly beyond, such as in the frame of the US-EU Communities of Research. This is possible only because XXXxXXX was a front runner in the public release of its work and has been an active promoter of open access to EU-funded project results. As experienced by this task, it can be very difficult to get the buy-in of partner organisations when it comes to setting up a harmonised data management system in a project. Data recording was and will likely remain a tedious task for those conducting assays in their laboratories. Data fitness for publication in journals seems different from, or lighter compared to what was required within the project to be able to exploit cross-WP data links, and not merely publish results in papers. Things are likely to change independently of this data management streamlining effort in NANoREG, since publishers are requiring more insight in data supporting the manuscripts, following models like ISA-TAB-Nano when requesting data from authors. The ISA-TAB-Nano specifications were developed by T1.5, with the partners themselves. T1.5's leading principle in developing the templates was 'keep it simple' for the users. Hopefully th...
