Assessing extent of degradation and the potential effects on the quantification of microplastics in the environment

Discarded plastic materials once in the environment may degrade into smaller sizes (micro or nano-microplastics) after withstanding several series of weathering factors such as mechanical degradation, sunlight and oxygen (photooxidation), temperature changes, salinity, and microbial action. These degradation processes, along with potential accumulation, persistence in the environment and possible behaviour as vessels or transportation for toxic chemicals, introduce another concern of widespread and ubiquitous plastic contamination yet to be fully understood. The vast majority of microplastic research have so far focused on the identification and quantification of environmental microplastics by comparing behaviours with virgin materials which have not gone through similar degradation processes. Specific behaviours and differences in properties, that set weathered and virgin plastics apart, may play an important role in the accuracy and reliability of quantification microplastic studies. Developing a method for assessing and characterising degradation extent via Pyr-GC/MS is important for advancing our understanding of chemical change, fate and behaviour in the environment. Determination of reduced polymer chains and appearance of oxidised compounds is integral to stablish to what extent microplastics are already weathered in the environment and whether these measurements are or will become a problem for microplastic quantification research. The overall aim of this research is to assess the effects of weathering on the quantification and analysis of the most common plastics currently found in the environment (i.e. PP, PE, PS) by Pyr-GC/MS and subsequently assess the potential of weathering-specific markers for further characterisation of environmental plastics.

Please note this is a PhD student confirmation milestone review.