Public concerns on microplastic (MP) pollution and its prevalence in urban runoff have grown exponentially. Huge amounts of MPs are transported from urban environments via surface runoff to different environment compartments, including rivers, lakes, reservoirs, estuaries, and oceans. The global concentrations of MPs in urban runoff range from 0 to 8580 particles/L. Understanding the sources, abundance, composition and characteristics of MPs in urban runoff on a global scale is a critical challenge because of the existence of multiple sources and spatiotemporal heterogeneity. Additionally, dynamic processes in the mobilization, aging, fragmentation, transport, and retention of MPs in urban runoff have been largely overlooked. Furthermore, the MP flux through urban runoff into rivers, lakes and even oceans is largely unknown, which is very important for better understanding the fate and transport of MPs in urban environments. Here, we provide a critical review of the global occurrence, transport, retention process, and sinks of MPs in urban runoff. Relevant policies, regulations and measures are put forward. Future global investigations and mitigation efforts will require us to address this issue cautiously, cooperating globally, nationally and regionally, and acting locally.

公众对微塑料 (MP) 污染及其在城市径流中的流行程度的担忧呈指数级增长。大量的 MPs 通过地表径流从城市环境输送到不同的环境隔间，包括河流、湖泊、水库、河口和海洋。城市径流中 MPs 的全球浓度范围为 0 至 8580 个粒子/L。由于存在多种来源和时空异质性，在全球范围内了解城市径流中 MPs 的来源、丰度、组成和特征是一项关键挑战。此外，城市径流中议员的动员、老龄化、碎片化、运输和保留的动态过程在很大程度上被忽视了。此外，通过城市径流进入河流、湖泊甚至海洋的 MP 通量在很大程度上是未知的，这对于更好地了解议员在城市环境中的命运和运输非常重要。在这里，我们对城市径流中 MPs 的全球发生、运输、保留过程和汇进行了批判性审查。提出相关政策、法规和措施。未来的全球调查和缓解工作将要求我们谨慎解决这个问题，在全球、国家和地区开展合作，并在当地采取行动。