Meso- and microplastics (MMPs) have attracted attention as globally dispersed environmental pollutants. However, little is known about the transfers of MMPs between aquatic and terrestrial systems. A large watershed-estuarine area of Bohai Sea was used as a case study, and soils and sediments were sampled adjacent to each other at a wide range of sites. MMPs were detected in all sediments (6.7–320 MMPs/kg) and soils (40–980 MMPs/kg), with the average abundance in soils double that in sediments on a dry mass basis. MMPs < 1 mm were most abundant and the dominant shape was film in both sediments and soils. Over twenty polymer types were detected and their compositions in sediments and soils were different. MMP abundance in sediments was lower in the upper catchment than the lower catchment, while the abundance of soil MMPs was the opposite. Despite the proximity of the sampling locations, no clear relationship was identified between the soil and sediment MMPs, suggesting low transfer between the two compartments and high heterogeneity of the sources. The missing associations between aquatic and terrestrial MMPs should be systematically examined in future studies, which is crucial for understanding the environmental fate and impacts of MMPs.

中观和微塑料（MMPs）作为全球分散的环境污染物引起了人们的关注。然而，关于 MMP 在水生和陆地系统之间的转移知之甚少。以渤海的一个大流域河口区域为案例研究，在广泛的地点对土壤和沉积物进行了相邻采样。在所有沉积物 (6.7–320 MMPs/kg) 和土壤 (40–980 MMPs/kg) 中都检测到 MMPs，土壤中的平均丰度是沉积物中干物质的两倍。MMP < 1 mm 最丰富，主要形状是沉积物和土壤中的薄膜。检测到二十多种聚合物类型，它们在沉积物和土壤中的成分不同。上流域沉积物中 MMP 的丰度低于下流域，而土壤 MMP 的丰度则相反。尽管采样位置很接近，但在土壤和沉积物 MMP 之间没有发现明确的关系，这表明两个隔间之间的转移较低，来源的异质性很高。在未来的研究中应系统地检查水生和陆生 MMP 之间缺失的关联，这对于了解 MMP 的环境归宿和影响至关重要。