Plastic pollution is a critical problem affecting freshwater and marine systems. Widespread use of products containing plastic microbeads, and the inability of wastewater treatment processes to remove these pollutants, is an increasing aquatic threat. Although marine plastic has been widely researched, relatively little is known about concentrations or toxic effects of plastic microparticle in freshwater ecosystems. Recent research indicates that highly urbanized areas are exposed to greater concentrations of microbead plastic pollution. Water column samples collected from the Raritan and Passaic Rivers will be investigated to calculate microbead densities and to aid in identifying potential microbead sources. Recovered plastic microbeads will be chemically analyzed to characterize both adsorbed persistent organic pollutants, as well as plasticizers in the beads themselves. Additionally, model vertebrate and invertebrate organisms will be exposed to microbeads to determine observable microbead toxicity effects.