Tracking Pollution Downstream: Linking Agricultural Land Use to PFAS and Microplastic Pollution in U.S. Streams

Abstract

Agricultural land use is a major source of non-point pollution, which contributes to the spread of emerging pollutants, such as per- and polyfluoroalkyl substances (PFAS) and microplastics. Despite increasing concern, the relationship between agricultural land-use patterns and the occurrence of these pollutants in aquatic systems remains under-explored. This study investigates these links by analyzing environmental monitoring data from agricultural stream sites across the U.S, including PFAS concentrations, microplastic assessments, and related environmental variables, as well as land-use descriptors categorized by agricultural activity. Preliminary analyses feature exploratory data visualizations and correlation assessments to characterize pollutant distributions. Spatial regression models are applied to quantify the effect of land-use factors on contaminant variability. To improve interpretability and accessibility, a Shiny-based interactive dashboard is developed to visualize spatial patterns and the dynamic trends of the key variables in the study. Together, these tools aim to improve insight into the spatial structure of emerging contaminants and support reproducible, data-driven environmental monitoring in aquatic agricultural ecosystems.