This study investigates the transport of microplastics (MPs) from biosolid-amended and manure-amended croplands via runoff. Higher MP concentrations were found in runoff from biosolid-amended plots compared to manure-amended and control plots. Fibers and fragments were the most prevalent MP morphologies in runoff, correlating with their smoother surfaces. The study quantifies the potential contribution of biosolids to MP contamination of US surface waters, highlighting a significant nonpoint source pollution pathway.
