Nano- and microplastics in the environment : presence, effects and their role as a Trojan horse for other pollutants

Overview & Synopsis

Today, plastic is a widely used material in a variety of sectors. As a result, much of the plastic ends up as waste in the environment, making it a global problem. It is estimated that around 80% of the plastics produced are discarded into the environment. Some of these plastics end up as nanoplastics and microplastics in aquatic systems. The presence of these plastics presents problems due to their size and ability to adsorb and transport emerging pollutants, and consequently facilitate their ingestion by living organisms. The understanding of the effects of micro- and nanoplastics is still limited, largely due to the lack of robust methods for their detection and quantification.In this context, this PhD thesis has aimed at the development of an analytical method for the detection, size characterisation and quantification of plastic microparticles by ICP-MS operated in single particle mode using microsecond dwell times. This method allowed the detection of polystyrene particles up to 1.2 µm in size by 13C isotopic tracing and was used to analyse for microplastics in personal care products and those released from food packagings. An analytical platform was also developed for the analysis of environmental samples, such as river water, by combination of Single Particle-ICP-MS, field emission scanning electron microscopy and Raman spectroscopy. The use of this platform allowed us to determine the presence and chemical identity of plastic microparticles in the analysed river water samples. Also, the adsorption capacity of environmental nanoplastics for emerging pollutants, such as gadolinium-based contrast agents, and their ability to act as competitors of natural colloids were studied. The ability of nanoplastics to act as vectors of emerging pollutants under environmental conditions was demonstrated.