INFLUENCES ON MICROPLASTIC CONCENTRATIONS IN PLUM RUN

Microplastic pollution poses a growing threat to both environmental and human health, with particles now ubiquitous in air, soil, water, and within living organisms. Understanding the accumulation of microplastics in aquatic environments is an emerging field, as such, studies on microplastic concentrations are limited in their geographical extent. This study focuses on Plum Run, a stream in the Chester County Watershed, to investigate whether atmospheric and meteorological conditions, particularly wind and rainfall, correlate with increased microplastic concentrations in waterways. We also looked at the variability of sampling of the same stream, which did produce highly variable counts, even within same-day sampling. Over the course of the year, we collected and analyzed 40 water samples from the stream. Microplastic particles within these samples were isolated, quantified through light microscopy, and classified into four polymer types using Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS). Our findings indicate a low correlation among microplastic particle counts in samples collected during windy and rainy periods, suggesting limited influence of these atmospheric conditions on microplastic levels in our waterway. Therefore, the high variability (n=40, mean=12.7, 1σ= 7.4) in microplastic counts and their low correlation with meteorological conditions, suggests that natural heterogeneity of plastic dispersal throughout aquatic systems may be a first order control on inter-sampling variability. While our results highlight a preliminary link, further quantitative studies are essential to further our understanding of the role meteorological factors play in transporting microplastics from air to water systems, contributing to the pollution in aquatic environments.