Phd in ENVIRONMENTAL AND EVOLUTIONARY BIOLOGY

Thesis title: 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 raised increasing concerns regarding the safety of workers employed in this field. The lack of comprehensive and reliable studies on the toxicity of nanomaterials (NMs), together with the scarcity of epidemiological investigations, has so far restricted the establishment of standardized occupational exposure limits. At the same time, the expanding use of NMs has led to their growing accumulation in environmental matrices — soil, water, and air — posing potential risks to human, animal, and plant health within terrestrial and aquatic ecosystems. In this context, the proposed PhD project aims to develop a multidisciplinary strategy for characterizing exposure to NMs in occupational settings, where engineered nanoparticles are expected to predominate over ultrafine particles of anthropogenic or natural origin. The strategy also includes the assessment of biological effects of exposure using simple, cost-effective model organisms that are not subject to ethical restrictions, with the ultimate goal of creating an integrated model applicable to different types of nanomaterials. The overarching objective, in line with the Prevention through Design (PtD) principle, is to quantify exposure levels and evaluate potential health and environmental risks from the earliest stages of product, process, and activity design. This approach will enable the minimization of hazards at their source and the implementation of effective safety measures throughout the entire life cycle of nanomaterials. In this contest, extensive monitoring and characterization of nanomaterials were conducted in various occupational settings where specific attention was given to airborne nanoparticle concentration, morphology, and chemical composition. The aim was to identify the main exposure sources and assess worker exposure levels under real production conditions. (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. 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 methods enabled a deeper understanding of NM accumulation pathways, supporting their future use in biomonitoring of exposed workers. (D1) Single particle ICP-MS method for the determination of TiO2 nano-and submicrometric particles in biological tissues (in preparation) (E1) Study of the bioaccumulation and metabolic effects of inhaled TiO2 nano-and submicrometer particles by Drosophila melanogaster (in preparation) The results underscore 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.