The spatiotemporal distribution and potential ecological risk of microplastics in sediment during different seasons in the Pearl River Delta, China

This study investigated the spatiotemporal distribution, morphological characteristics, socio-economic indicators, and the potential ecological risk posed by microplastics (MPs) in the sediment during different seasons in the Pearl River Delta. The spatiotemporal distribution and morphological characteristics of MPs were unbal-anced and diverse. The color, shape, and size distribution of MPs during the rainy season were dominated by gray (40.4 %), strip-shaped (61.5 %) and 100 - 500 mu m (65.4 %). Synchronously, the dominant color, shape, and size dis- tribution of MPs in the dry season were brown (22.2 %), granular (75.6 %) and 0 -100 mu m (57.4 %). Furthermore, the abundances of MPs exhibited varying degrees of correlation with some socio-economic indicators; risk assessment indicated that the potential ecological risks posed by MPs were high, universal, and underestimated. The findings provide a theoretical basis for future research on MPs and for improving the awareness of the need for MP risk management in the Delta.