Estimation of Microplastic Generation from Plastic Debris Littered on River Basin Based on UV Exposure Experiments

Summary

UV irradiation experiments on plastic beverage bottle caps examined changes in molecular structure, surface morphology, and mass loss to estimate microplastic generation rates from littered plastic debris. Annual microplastic generation from bottle caps scattered across Japan's river basins was estimated at 22.6 kg, representing less than 0.01% of annual river plastic waste flux but highlighting the need for further research.