Prevention of the risk of occupational exposure to nanomaterials through a multidisciplinary strategy of characterization of airborne dust and evaluation of the effects

The rapid development of the nanotechnology sector has raised concerns regarding the safety of workers involved in the production and use of nanomaterials (NMs). The lack of comprehensive and reliable studies on the toxicity of NMs, combined with the availability of epidemiological investigations, has so far hindered the establishment of standardized occupational exposure limits. At the same time, the growing use of NMs has led to their progressive accumulation in environmental matrices — soil, water, and air — with potential risks to human, animal, and plant health within terrestrial and aquatic ecosystems. Within this context, the presented PhD project aims to develop a multidisciplinary strategy for the characterization of exposure to NMs in occupational settings, where engineered nanoparticles are expected to predominate over ultrafine particles of natural or anthropogenic origin. The strategy also includes the assessment of biological effects of exposure through the use of simple, cost-effective model organisms that are not subject to ethical constraints, with the ultimate goal of defining an integrated model applicable to different types of nanomaterials. In line with the Prevention through Design (PtD) principle, the overarching objective is to quantify exposure levels and assess potential risks to human health and the environment from the earliest stages of product, process, and activity design. This approach enables hazards minimization at their source and the implementation of effective safety measures throughout the entire life cycle of nanomaterials. In this contest, in-depth monitoring and characterization of nanomaterials were conducted in various occupational settings with particular emphasis on the concentration, morphology, and chemical composition of airborne nanoparticles. These studies allowed the identification of the main exposure sources and the evaluation of workers’ exposure levels under real production conditions, as documented in published and ongoing studies. (A1) Prevention-through-design approach to mitigate workers’ exposure in the graphene production processes. Journal of Physics: Conference Series (2024), 2695, 012003 https://doi.org/10.1088/1742-6596/2695/1/012003 (B1) Scaling up the graphene production from R&D to the pilot plant stage: implications for workers’ exposure to airborne nano-objects. NanoImpact (2025), 38, 100555 https://doi.org/10.1016/j.impact.2025.100555 (C1) Potential exposure to nano and microparticles during injection molding of glass fiber polymer composites. Aerosol Science and Technology (2025), 1–13 https://doi.org/10.1080/02786826.2025.2586713 In parallel, an in vivo study was conducted using Drosophila melanogaster, to investigate the biological effects of exposure concentration. The findings highlighted exposed-organism alterations, thereby providing insights into the broader impacts of nanomaterials not only on human health but also on ecosystems. In addition, advanced analytical methods were developed and validated to investigate nanomaterial bioaccumulation in biological tissues. The validation process included the use of state-of-the-art hyphenated techniques (e.g., spICP-MS, AF4-ICP-MS) to characterize and quantify nanoscale materials in biological tissues. These approaches allowed a deeper understanding of NM accumulation mechanisms and support their future application in occupational biomonitoring strategies. (D1) Single particle ICP-MS method for the determination of TiO2 nano-and submicrometric particles in biological tissues. Analytica (2026), 7, 9, https://doi.org/10.3390/analytica7010009 (E1) Study of the bioaccumulation and metabolic effects of inhaled TiO2 nano-and submicrometer particles by Drosophila melanogaster. (in preparation) Overall, the results highlight the need to address the assessment of nanomaterial-related risks through an integrated perspective that simultaneously considers occupational, environmental, and biological dimensions. Within this framework, the development of safe-by-design strategies and the implementation of prevention through design principles during the early stages of nanomaterial development appear essential to minimize potential adverse effects and promote the sustainable use of nanotechnology, to ensure responsible technological innovation and the protection of public and environmental health. The findings presented in this thesis derive from a series of publications and manuscripts currently under review and in preparation, which collectively address occupational exposure assessment, biological effects, and analytical method development.