Storm-driven transport and deposition of atmospheric microplastics in remote Newfoundland, Canada

Abstract

Microplastic pollution is an increasing global concern due to its pervasiveness in all types of environments around the world. In recent years, the study of how microplastic particles travel across the atmosphere has attracted increasing attention, and preliminary results have shown that rain and wind can transport and deposit large quantities of microplastics in remote regions. However, how intense meteorological events such as hurricanes can influence microplastic pollution is still unknown. In this MSc thesis, I present two studies that investigate the dynamics of atmospheric microplastic transport and deposition in Newfoundland, Canada, a relatively remote region with low population density and susceptible to intense storms. In the first study, the passage of Hurricane Larry over Newfoundland in 2021 was used to quantify storm-driven transport and deposition of microplastics. I collected atmospheric samples before, during, and after the storm to quantify microplastic deposition. Chemical analysis and back-trajectory modelling determined the majority of microplastics collected were likely sourced from the ocean. To quantify whether tropical cyclones and nor’easters can have a dominant role in microplastic pollution in the region, I collected remote lake bottom sediment samples across Newfoundland. The results show microplastics were present in all samples and had a similar size distribution to the particles deposited during Hurricane Larry, identifying the possible link of microplastic deposition to storm events. This research provides quantitative data for the first time on how hurricanes may influence microplastic pollution in remote regions of North America and provided a baseline dataset for future works. This research contributes to a comprehensive understanding of the fate and impact of atmospheric microplastics in remote environments.