Human and environmental exposure to Copper-based engineered nanomaterials (Cu-ENMs): transformation and toxicological effects

The peculiar properties of engineered nanomaterials (ENMs), i.e. high surface-to-volume ratio and quantum effect, provide great opportunity for technical development of novel or improved products, but the potential risk associated with these materials requires further research work. Unlike bulk chemicals, where the main environmental fate processes are controlled by the partitioning coefficient, nanoparticles are dynamic entities that undergo transformations depending on the chemical composition of the media in which they are dispersed (i.e. pH, ionic strength, organic matter and suspend particulate matter). This Ph.D. thesis work focused on the characterization and transport and fate of copper based nanoparticles (Cu-ENMs) i.e. nano CuO and Cu2CO3(OH)2. These materials are widely used in wood preservation, in paints formulation and in antibacterial products because of the recognized efficiency in killing a range of microorganisms. Both distribution and dissolution of Cu-ENMs in biological and environmental media have been studied by using a combination of analytical techniques such as DLS (Dynamic Light Scattering), TEM (Transmission Electron Microscopy), sp-ICP-MS (single particle Inductively Coupled Plasma-Mass Spectrometry) and CSA (Centrifugal Separation Analysis). The results obtained so far can be helpful to elucidate the dynamic equilibria between Cu-ENMs and environmental or biological media. Furthermore, a methodological approach to detect and quantify Cu-ENMs in biological tissues coming from toxicological tests was developed by combining different analytical techniques. The overall experimental activity led to the draft of three manuscripts that are discussed in detail in this thesis.