Percorrer por autor "Bou, David"
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- Incidental nanoparticle characterisation in industrial settings to support risk assessment modellingPublication . Moreno-Martín, Veronica; López, Maria; Bou, David; Fraga, Sónia; Teixeira, João Paulo; López-Lilao, Ana; Sanfélix, Vicenta; Monfort, Eliseo; Viana, MarResearch on nanoparticle (NP) release and potential exposure can be assessed through experimental field campaigns, laboratory simulations, and prediction models. However, risk assessment models are typically designed for manufactured NP (MNP) and have not been adapted for incidental NP (INP) properties. A notable research gap is identifying NP sources and their chemical, physical, and toxicological properties, especially in real-world settings. This work aims to provide insights into the release and physico-chemical properties of INP while contributing to improving models for INP release. INP release was evaluated through a case study in a ceramic tile firing facility, where aerosol (10 nm - 10 μm) properties were determined. The Control Banding (CB) Nanotool model was applied to test outputs based on provided input parameters. Results: demonstrate the constant generation and release of INP during tile firing, with NP concentrations up to 68711/cm³ and mean diameters of 37 nm, with 95% smaller than 100 nm. Particle morphology was mostly spherical, suggesting nucleation from precursor gases as the main formation mechanism. INP chemical composition was driven by primary ceramic components, while trace elements like Ni and Ti exhibited sizedependent patterns. In vitro cell viability tests indicated low to medium cytotoxicity of PM2 aerosols, decreasing human alveolar epithelial cell viability in a concentration-dependent manner. Applying the risk model with varying input parameters revealed that the risk level (RL) based on severity scores decreased when aerosol size distribution data were used, illustrating the model’s sensitivity to input variables. We conclude on the need for comprehensive experimental datasets to support risk assessment models and achieve effective risk management strategies in real-world scenarios.
- Potential human exposure and risks of incidental nanoparticles released during rotary dry cutting of ceramic tilesPublication . Moreno-Martín, Verónica; López, Maria; Roldan, Cristian; Bou, David; Fraga, Sonia; Teixeira, João Paulo; López-Lilao, Ana; Sanfélix, Vicenta; Moliner, Raúl; Monfort, Eliseo; Viana, MarRotary dry cutting and rectifying of ceramic tiles are sources of fine particulate matter (PM2.5) and nanoparticles (NPs). These activities are typically carried out inside industrial facilities during the manufacturing process, as well as outdoors and in residential indoor spaces during the installation phase, where mitigation measures are seldom implemented. This work aimed to understand the particle formation and release mechanisms, as well as particle properties (physical, chemical, and toxicological) and potential impacts on human health and the environment, for particles generated during ceramic tile rotary dry cutting operations. Aerosols were characterised in terms of particle number and mass concentrations, chemical composition, morphology and in vitro cytotoxicity. Two types of commercially available and representative tiles were tested in controlled chamber experiments: porous and non-porous ceramic body tiles (referred to in this work as A and B types, respectively). Results evidenced the release of fine particles and NPs during dry cutting of both materials, in comparable concentrations (20.000–45.000/cm3, 1-min average). However, the particle size distribution was significantly finer from A tiles (70% of the particle number concentration was nanosized (<100 nm)) in comparison to B tiles (<20%). While airborne particle chemical profiles were similar for both types of materials in the coarser size fractions (>0.6 μm), in the smaller size fractions (<0.6 μm) larger differences were observed. The chemical composition of airborne aerosols was consistent with that of the deposited dust. In vitro cytotoxicity responses evidenced statistically significant differences between exposure to aerosols from both types of tiles: cell viability was lower after exposure to aerosols from A tiles (50% at the original concentration) compared to those from B tiles, which exhibited high cell viability regardless of the aerosol concentration. Overall, results evidenced NP formation and release during rotary dry cutting of ceramic tiles, varying physical-chemical and cytotoxic profiles as a function of the material being processed, and highlight this activity as a potential health hazard in scenarios where prevention and mitigation measures are not implemented.