Browsing by Author "Vaquero-Moralejo, Celina"
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Item Analysis of multivariate stochastic signals sampled by on-line particle analyzers: Application to the quantitative assessment of occupational exposure to NOAA in multisource industrial scenarios (MSIS): Application to the quantitative assessment of occupational exposure to NOAA in multisource industrial scenarios (MSIS)(2015-05-26) López de Ipiña, J.M.; Vaquero-Moralejo, Celina; Gutierrez-Cañas, C.; Pui, D.Y.H.; Tecnalia Research & Innovation; SMART_MON; PRINTEXIn multisource industrial scenarios (MSIS) coexist NOAA generating activities with other productive sources of airborne particles, such as parallel processes of manufacturing or electrical and diesel machinery. A distinctive characteristic of MSIS is the spatially complex distribution of aerosol sources, as well as their potential differences in dynamics, due to the feasibility of multi-task configuration at a given time. Thus, the background signal is expected to challenge the aerosol analyzers at a probably wide range of concentrations and size distributions, depending of the multisource configuration at a given time. Monitoring and prediction by using statistical analysis of time series captured by on-line particle analyzersin industrial scenarios, have been proven to be feasible in predicting PNC evolution provided a given quality of net signals (difference between signal at source and background). However the analysis and modelling of non-consistent time series, influenced by low levels of SNR (Signal-Noise Ratio) could build a misleading basis for decision making. In this context, this work explores the use of stochastic models based on ARIMA methodology to monitor and predict exposure values (PNC). The study was carried out in a MSIS where an case study focused on the manufacture of perforated tablets of nano-TiO2 by cold pressing was performed.Item Development of Protective Clothing against Nanoparticle Based on Electrospun Nanofibers(2012) Faccini, M.; Vaquero-Moralejo, Celina; Amantia, D.; Tecnalia Research & Innovation; PRINTEXIn this paper, the development of efficient protective clothing against nanoparticulate aerosols is presented. Nanofibrous mats of polyamide 6 (PA6) were deposited onto a nonwoven viscose substrate by electrospinning technique. The influence of electrospinning parameters, including solution concentration, viscosity, and conductivity, was studied for the production of nonwovens with controlled fiber diameter showing a size distribution ranging from 66 to 195 nm. By varying several process parameters, textiles with different thickness of the nanofiber layer and thus air permeability were obtained. A hot-press lamination process using a thermoplastic resin as glue was applied to improve the adhesion of the nanofiber layer onto the textile support. After 1500 cycles of repeated compression and torsion, the nanofiber layer was still firmly attached to the support, while mechanical damage is visible in some areas. The penetration of NaCl particles with diameter ranging from 15 to 300 nm through the electrospun textiles was found to be strongly dependent on nanofiber layer thickness. A really thin nanofiber coating provides up to 80% retention of 20 nm size particles and over 50% retention of 200 nm size nanoparticles. Increasing the thickness of the nanofiber mat, the filtration efficiency was increased to over 99% along the whole nanoparticle range. The results obtained highlight the potential of nanofibers in the development of efficient personal protective equipments against nanoparticles.Item Exposure assessment to engineered nanoparticles handled in industrial workplaces: The case of alloying nano-TiO2 in new steel formulations: The case of alloying nano-TiO2 in new steel formulations(2016-12-01) Vaquero-Moralejo, Celina; Gutierrez-Cañas, C.; Galarza, N.; López de Ipiña, J.M.; López de Ipiña, J. L.; Tecnalia Research & Innovation; PRINTEX; SMART_MONThis experimental study addresses the occupational exposure assessment to nano-TiO2 (AEROXIDE ® TiO2 P 25, EVONIK GmbH) along the processing steps of ingot steelmaking at three sites, whose characteristics range from conditioned room to multi-source industrial environments (MSIS). In Site A, which is a MSIS of multiproduct flexible production, the alloying tablets are manufactured through compression of bulk nano-powder at room temperature. Tablets are then assembled in Site B, which is a lab room equipped with local exhaust ventilation (LEV). The alloying of steel takes place in Site C, which is a full-scale casting hall where substantial amounts of material per batch (3000 kg steel/batch) are processed in open-face molds and severe working conditions prevail. A comprehensive experimental strategy based on simultaneous measurements using direct reading instruments (DRI) and time integrated filter-based sampling has been set up. The main goal of this unusual campaign at an industrial site was to determine the suitability of the various options within the decision frame of the current methodological approaches, mainly chemical- and site-dependent. In Site A the DRI were of limited applicability for the quantification of exposure, because of a high-variability of the background and a characteristic low but unstable counting in the coarse size range where agglomerates of nano-TiO2 are present. In Site B, under controlled environmental conditions no interferences were relevant. Therefore, real-time devices showed no change in the total particle concentration suggesting that tasks performed did not result in any detectable release of the nano-powder. Readings in the size range>0.3 µm showed low-signals, in the order of the device accuracy, that could not be linked to any potential release. However, the mass concentration of TiO2, as obtained by the off-line analysis of personal breathing zone (PBZ) samples, spans from 0.021 to 0.296 mg/m3 in both Sites, which seems to be due to big agglomerates observed by scanning electron microcopy (SEM). In Site C (steel foundry) the on-line instruments could not be used due to access restrictions and severe working conditions. Therefore, only personal sampling approach was used, including the comparative study with and without nanomaterial, which indicates no additional or TiO2 specific workers exposure. This work highlights how, in this particular case, occupational exposure to engineered nanoparticles (ENP) is better assessed through off-line analysis of personal filter samples. The DRI, however, are of unquestionable applicability as real-time monitors to quantify engineering controls efficiency and, thus, for risk management activities and decision making. The need for a scientific consensus in performing such an exposure assessment in industrial contexts is stressed.Item A methodology on how to create a real-life relevant risk profile for a given nanomaterial(2018-01-01) Schimpel, Christa; Resch, Susanne; Flament, Guillaume; Carlander, David; Vaquero-Moralejo, Celina; Bustero, Izaskun; Falk, Andreas; Tecnalia Research & Innovation; PRINTEXWith large amounts of nanotoxicology studies delivering contradicting results and a complex, moving regulatory framework, potential risks surrounding nanotechnology appear complex and confusing. Many researchers and workers in different sectors are dealing with nanomaterials on a day-to-day basis, and have a requirement to define their assessment/management needs. This paper describes an industry-tailored strategy for risk assessment of nanomaterials and nano-enabled products, which builds on recent research outcomes. The approach focuses on the creation of a risk profile for a given nanomaterial (e.g., determine which materials and/or process operation pose greater risk, where these risks occur in the lifecycle, and the impact of these risks on society), using state-of-the-art safety assessment approaches/tools (ECETOC TRA, Stoffenmanager Nano and ISO/TS 12901-2:2014). The developed nanosafety strategy takes into account cross-sectoral industrial needs and includes (i) Information Gathering: Identification of nanomaterials and hazards by a demand-driven questionnaire and on-site company visits in the context of human and ecosystem exposures, considering all companies/parties/downstream users involved along the value chain; (ii) Hazard Assessment: Collection of all relevant and available information on the intrinsic properties of the substance (e.g., peerreviewed (eco)toxicological data, material safety data sheets), as well as identification of actual recommendations and benchmark limits for the different nano-objects in the scope of this projects; (iii) Exposure Assessment: Definition of industry-specific and application-specific exposure scenarios taking into account operational conditions and risk management measures; (iv) Risk Characterisation: Classification of the risk potential by making use of exposure estimation models (i.e., comparing estimated exposure levels with threshold levels); (v) Refined Risk Characterisation and Exposure Monitoring: Selection of individual exposure scenarios for exposure monitoring following the OECD Harmonized Tiered Approach to refine risk assessment; (vi) Risk Mitigation Strategies: Development of risk mitigation actions focusing on risk prevention.Item Modeling of occupational exposure to accidentally released manufactured nanomaterials in a production facility and calculation of internal doses by inhalation(2016-07-02) Pilou, Marika; Vaquero-Moralejo, Celina; Jaén, María; López de Ipiña, J.M.; Neofytou, Panagiotis; Housiadas, Christos; Lopez De Ipiña Peña, Jesús; Tecnalia Research & Innovation; PRINTEX; SMART_MONBackground: Occupational exposure to manufactured nanomaterials (MNMs) and its potential health impacts are of scientific and practical interest, as previous epidemiological studies associate exposure to nanoparticles with health effects, including increased morbidity of the respiratory and the circulatory system. Objectives: To estimate the occupational exposure and effective internal doses in a real production facility of TiO2 MNMs during hypothetical scenarios of accidental release. Methods: Commercial software for geometry and mesh generation, as well as fluid flow and particle dispersion calculation, were used to estimate occupational exposure to MNMs. The results were introduced to in-house software to calculate internal doses in the human respiratory tract by inhalation. Results: Depending on the accidental scenario, different areas of the production facility were affected by the released MNMs, with a higher dose exposure among individuals closer to the particles source. Conclusions: Granted that the study of the accidental release of particles can only be performed by chance, this numerical approach provides valuable information regarding occupational exposure and contributes to better protection of personnel. The methodology can be used to identify occupational settings where the exposure to MNMs would be high during accidents, providing insight to health and safety officials.Item Nanofiber-based filters as novel barrier systems for nanomaterial exposure scenarios(2011) Faccini, M.; Amantia, D.; Vázquez-Campos, S.; Vaquero-Moralejo, Celina; López de Ipiña, J.M.; Aubouy, L.; De Ipĩa, J. M.López; Tecnalia Research & Innovation; PRINTEX; SMART_MONIn this article our latest advances in the development of efficient barrier systems against micro- and nano-particulate materials are presented. Nanofibrous polyamide 6 (PA6) mats were fabricated by electrospinning onto a nonwoven viscose substrate. The influence of electrospinning parameters including solution concentration, viscosity, and conductivity, were studied for the production of nonwovens with different fiber size distribution ranging from 74 to 261 nm in diameters. Moreover, the formation of nanowebs (30-40 nm) which are widely distributed among fibers was observed. By varying several process parameters, membranes with different thickness of the nanofiber layer and therefore air permeability and nanoparticle filtration efficiency were obtained.Item Occupational exposure to nano-TiO2 in the life cycle steps of new depollutant mortars used in construction(2015-05-26) Vaquero-Moralejo, Celina; Galarza, N.; López de Ipiña, J.M.; Gutierrez-Cañas, C.; Múgica, I.; Aragón, G.; Jaen, M.; Pina, R.; Larraza, I.; Esteban-Cubillo, A.; Thompson, D.; Pui, D.Y.H.; Gelarza, N.; De Ipiña, J. L.López; Tecnalia Research & Innovation; PRINTEX; SMART_MONThe present work is focused on the measurement of workers exposure to nano-TiO2 in the life cycle steps of depollutant mortars. It has been done in the framework of the SCAFFOLD project, which aims at the management of potential risks arising from the use of manufactured nanomaterials in construction. Main findings can be summarized as follows: (1) The occupational exposure to nano- TiO2 is below 0.3 mg/m3 for all measured scenarios. The highest concentrations were measured during the cleaning task (in the nano- TiO2 manufacturing process) and during the application (spraying) of depollutant coatings on a wall. (2) It was found a high release of particles above the background in several tasks as expected due to the nature of the activities performed. The maximum concentration was measured during drilling and during adding powder materials (mean total particle concentration up to 5.591E+04 particles/cm3 and 5.69E+04 particles/cm3). However, considering data on total particle concentration released, no striking differences have been observed when tasks have been performed using conventional materials in the sector (control) and when using materials doped with nano-objects.Item Polyfire project- an example of an industrial research project promoting safe industrial production of fire-resistant nanocomposites(2011) Vaquero-Moralejo, Celina; López de Ipiña, J.M.; Galarza, N.; Hargreaves, B.; Weager, B.; Breen, C.; Tecnalia Research & InnovationNew developments based on nanotechnology have to guarantee safe products and processes to be accepted by society. The Polyfire project will develop and scale-up techniques for processing halogen-free, fire-retardant nanocomposite materials and coatings based on unsaturated polyester resins and organoclays. The project includes a work package that will assess the Health and Environmental impacts derived from the manipulation of nanoparticles. This work package includes the following tasks: (1) Identification of Health and Environment Impacts derived from the processes, (2) Experimentation to study specific Nanoparticle Emissions, (3) Development of a Risk Management Methodology for the process, and (4) A Comparison of the Health and Environmental Impact of New and Existing Materials. To date, potential exposure scenarios to nanomaterials have been identified through the development of a Preliminary Hazard Analysis (PHA) of the new production processes. In the next step, these scenarios will be studied and simulated to evaluate potential emissions of nanomaterials. Polyfire is a collaborative European project, funded by the European Commission 7th Framework Programme (Grant Agreement No 229220). It features 11 partners from 5 countries (5 SMEs, 3 research institutes, 2 large companies, 1 association) and runs for three years (1st September 2009 – 31st August 2012). This project is an example of an industrial research development which aims to introduce to the market new products promoting the safe use of nanomaterials.Item Strategies, methods and tools for managing nanorisks in construction(2015-05-26) López de Ipiña, J.M.; Vaquero-Moralejo, Celina; Boutry, D.; Damlencourt, J.F.; Neofytou, P.; Pilou, M.; Jankowska, E.; Larraza, I.; Pina, R.; Fernández, S.; Contreras, S.; Romero, A.; Calderon, M.; Swiezewsk, P.; Otkallo, K.; Pintea, A.; Salazar, C.; Oroz, T.; Hargreaves, B.; Ciobanu, R.; Tabrea, A.; Hazebrouck, B.; Salvi, O.; Stockmann-Juvala, H.; Vaananen, V.; Pui, D. H. Y.; Thompson, Drew; Tecnalia Research & Innovation; SMART_MON; PRINTEXThis paper presents a general overview of the work carried out by European project SCAFFOLD (GA 280535) during its 30 months of life, with special emphasis on risk management component. The research conducted by SCAFFOLD is focused on the European construction sector and considers 5 types of nanomaterials (TiO2, SiO2, carbon nanofibres, cellulose nanofibers and nanoclays), 6 construction applications (Depollutant mortars, selfcompacting concretes, coatings, self-cleaning coatings, fire resistant panels and insulation materials) and 26 exposure scenarios, including lab, pilot and industrial scales. The document focuses on the structure, content and operation modes of the Risk Management Toolkit developed by the project to facilitate the implementation of "nano-management" in construction companies. The tool deploys and integrated approach OHSAS 18001 - ISO 31000 and is currently being validated on 5 industrial case studies.Item Towards an optimal adaptation of exposure to NOAA assessment methodology in Multi-Source Industrial Scenarios (MSIS): the challenges and the decision-making process: The challenges and the decision-making process(2017-06-01) López de Ipiña, J.M.; Vaquero-Moralejo, Celina; Gutierrez-Cañas, C.; Tecnalia Research & Innovation; SMART_MON; PRINTEXIt is expected a progressive increase of the industrial processes that manufacture of intermediate (iNEPs) and end products incorporating ENMs (eNEPs) to bring about improved properties. Therefore, the assessment of occupational exposure to airborne NOAA will migrate, from the simple and well-controlled exposure scenarios in research laboratories and ENMs production plants using innovative production technologies, to much more complex exposure scenarios located around processes of manufacture of eNEPs that, in many cases, will be modified conventional production processes. Here will be discussed some of the typical challenging situations in the process of risk assessment of inhalation exposure to NOAA in Multi-Source Industrial Scenarios (MSIS), from the basis of the lessons learned when confronted to those scenarios in the frame of some European and Spanish research projects.