Vignesh Rajkumar Lakshmanan

The Plastic Trail: Investigating Source-to-Sink Microplastic Transfers in Agricultural Catchment

Microplastics (MPs) are omnipotent and pervasive. MPs in freshwater and terrestrial ecosystems have been examined worldwide. Studies have revealed the impacts on the soil properties and soil organisms. As the MPs have been demonstrated to transport to the human body through the trophic pathways, additional evidence of MPs in the human blood along with inflammation, oxidative stress and respiratory issues in human body necessitates a critical need to address the issue of MPs pollution. To comprehend the behaviour of MPs in terrestrial ecosystems, it is essential to examine both their sources and transport mechanisms. The transport of MPs from terrestrial environments primarily occurs via runoff, which directs them to freshwater bodies such as rivers or lakes. A thorough examination of the transport of MPs from terrestrial to freshwater systems necessitates in-depth research at the catchment scale. This study examines the origins and transport dynamics of MPs in the Louroux basin of the Loire River valley. The transport of MPs within the catchment area and freshwater systems will be determined through MPs in suspended sediments & the bed load and the bed load flux determined through hydrophones. Furthermore, we will assess the settling behaviour of MPs in the lake system by examining the characteristics of heteroaggregation with suspended sediments. The sources of MPs will be determined through MPs characteristics and statistical techniques such as Network analysis, cluster analysis, Principal Component Analysis and Multiple Linear Regression The large scale land use changes of Louroux catchment during the late 20th century coincides with the mass production of plastics around 1950s. Hence, the sediment core analysis from the lake will provide insights into the evolution of MPs, influence of land use changes on the transport of MPs at the catchment scale, owing to the temporal correlation between plastic mass production and extensive land use changes in the region.