Nanoparticles in metal recycling and powder manufacturing for 3D printing: exposure, bioavailability, toxicity and health risks
- Time period:
- 1 January 2026 – 31 December 2029
- Project leader:
- Hanna Karlsson
- Funder:
- Forte
- Type of award:
- Project grant
- Total funding:
- 4,999,000 SEK
Research questionIn society, the demands for recycling and use of resource-efficient techniques such as additive manufacturing (3D printing) to produce various components are increasing. This project focuses on health risks for workers involved in the recycling of metals from metallic dust waste or producing and reusing metal powders for 3D-printing. A particular focus is on exposure to nanoparticles (<100 nm) and investigating to what extent they are more harmful than larger particles. The project combines occupational hygiene measurements with fundamental research on the surface chemistry, properties, and toxicity of the particles to answer the following important questions:Are nanoparticles present in the work environment, and are the limit values for airborne metals exceeded?How do the size distribution, surface composition, and properties of the particles change at different process stages?Can airborne particle exposure be correlated with metal levels in the nose and urine, and how do the properties of the particles affect body uptake?Can metal levels in nasal lavage fluid (NLF) be correlated with inflammation in the lung/nose and changes in protein expression in nasal epithelium?How do the properties of the particles affect genotoxicity, inflammation and protein expression in cell cultures?What are the relationships between inflammatory responses in the nose/lung and effects in in vitro models?What cumulative dose of nano- vs. microparticles is deposited in the alveoli after long-term exposure?How can data from experiments with simulated body fluids and cell cultures be used to understand effects in humans?What occupational health measures should be prioritized to reduce the risk of illness in powder manufacturing and metal recycling? Data and methodIn three different work packages, we will:Quantify the exposure of workers handling steel dust waste for recycling or producing and reusing metal powders for 3D-printing, focusing on nanoparticles and metals. Study inflammation in the airways (FeNO) and markers in urine (metals) and NLF (metals, cytokines, protein expression) and propose preventive measures.Characterize collected nanoparticles regarding surface properties, size, metal release, and chemical form. Correlate these properties with toxic effects in cell experiments (genotoxicity, inflammation and protein expression) in models for the nose and lungs. Compare the effects of nano- vs. microparticles.Model lung dose of particles (MPPD) and analyze in vitro-in vivo relationships.Societal relevance and utilizationThe increased interest in circular flows requires increased recycling of metals and the use of resource-efficient techniques such as 3D printing. To ensure sustainable material development, research on health risks must be integrated into the development of new products and recycling. This interdisciplinary project combines applied methodology in collaboration with companies and advanced research. The goal is to increase knowledge about exposure and health effects of inhaling nanoparticles. The project is also expected to provide insights into the relationship between in vitro effects and those measured in humans, which is crucial for better understanding how in vitro methods can be used to assess occupational health risks.Plan for project realizationThe project is carried out in collaboration with two companies involved in industrial metal recycling and the production and reuse of metal powder for 3D printing. During 2026, measurements, sampling, analysis of markers and collection of nanoparticles and larger particles will be conducted, followed by proposals for preventive measures. Detailed analyses of particle characterization, metal release, chemical form, toxicity, and lung dose modeling will take place in 2027-2028. The project will be compiled, and scientific articles will be completed in 2028.