The characterization of microplastics helps to improve sustainable management practices in aquatic ecosystems impacted by plastic litter. Plastic litter and microplastics from four ocean beaches in the Niterói municipality was evaluated in winter and summer. The collection and preparation of microplastic sample procedures followed on the protocol developed by the RLA7025 Project of the International Atomic Energy Agency. Marine debris followed to the United Nations Environment Program protocol. The polymer was characterized by ATR-FTIR technique.The Clean Coast Index was used to determine the degree of dirt on the beaches. Polyethylene (43%) and Polystyrene (52%) were the most abundant microplastics. The plastic is the most abundant category; representing 85% in winter and 73% in summer.The main sources are related to the consumption of drinks and food. These results emphasize the importance of reverse logistics and the value chain for packaging material and the need for effective actions managing solid waste.

微塑料的特性有助于改善受塑料垃圾影响的水生生态系统的可持续管理实践。在冬季和夏季对来自 Niterói 市四个海滩的塑料垃圾和微塑料进行了评估。微塑料样品的收集和制备程序遵循国际原子能机构 RLA7025 项目制定的协议。海洋垃圾遵循联合国环境规划署协议。聚合物通过 ATR-FTIR 技术进行表征。清洁海岸指数用于确定海滩上的污垢程度。聚乙烯（43%）和聚苯乙烯（52%）是最丰富的微塑料。塑料是最丰富的类别；冬季占 85%，夏季占 73%。主要来源与饮料和食物的消费有关。这些结果强调了逆向物流和包装材料价值链的重要性，以及采取有效措施管理固体废物的必要性。