Microplastic Transport in Urban Agricultural Systems: Characterization, Drivers, and Implications for Stormwater Management

Abstract Submission: Urban agriculture enhances food security and ecosystem services, but contaminants like microplastics threaten soil health in urban farms. Despite extensive research on common pollutants, microplastics as emerging contaminants have received limited attention, particularly regarding their transport via stormwater runoff to urban farms. Information on the effectiveness of urban conservation practices in preventing microplastics from reaching urban farms is scarce. This study aims to investigate microplastic transport to urban farms under various weather patterns, focusing on quantifying abundance, size distribution, and types, identifying sources, and exploring relationships between microplastic characteristics and transport factors. Field investigations and laboratory analyses, including multiple digestions, gravity settling, filtrations, optical microscopy, and µ-FTIR spectroscopy, are conducted to characterize microplastics ranging from 50 to 1000 µm. Preliminary results show various microplastic types, with LDPE being the most abundant, followed by PET, PS, PVC, HDPE, and Nylon. Most microplastics were smaller than 500 μm, with size distribution varying slightly between samples collected at different rain intervals. Weather data will be analyzed for rainfall characteristics, wind speed, and antecedent conditions. Statistical modeling techniques, including multivariate regression analysis, time series analysis, and principal component analysis, will be employed to develop empirical relationships linking microplastic features with meteorological parameters, soil, and land surface characteristics. This study will elucidate key factors influencing microplastic transport in urban drainage systems during and after hurricane events, informing policy decisions on urban water management and agricultural practices to enhance food security and ecosystem health in urban environments.
Keywords: Microplastics, Stormwater, Urban agriculture, Contaminant transport, Urban water management

Learning Objectives/Expected Outcome (Optional) : The data-driven approaches of this study will help elucidate the key factors influencing microplastic transport and distribution in urban drainage systems during and after hurricane events. Furthermore, outcomes will inform policy decisions regarding urban water management and agricultural practices, contributing to enhanced urban food security and ecosystem health.