Current advances in microplastic contamination in aquatic sediment: Analytical methods, global occurrence, and effects on elemental cycling.

The ubiquitous presence of microplastics in aquatic sediment represents an anthropogenic stressor on benthic organisms and elemental cycling. However, a comprehensive understanding of the identification methods, global distribution, and their effects on elemental cycling in aquatic sediment is still lacking. Identification methods and concentrations of microplastics in sediment were compiled from 185 peer-reviewed articles by searching the Web of Science with keywords "microplastic", "identification", and "sediment" during 2013–2022. Microscopy and infrared spectroscopy were predominantly used for detecting microplastics in the sediment. China and the United States were the research hotspots. Microplastics can influence carbon cycling directly by impacting the carbon storage in sediment or indirectly by affecting the activities of microbial communities and benthic organisms. Additionally, the effects of microplastics on elemental cycling were closely related to the type, size, concentration, and exposure time of microplastics. Future studies are still needed to explore the long-term effects of microplastics on the elemental cycling in aquatic ecosystems. [Display omitted] • Microscopy and infrared spectroscopy were widely used to identify microplastics. • China and the United States were the research hotspots of microplastics in sediment. • Microplastics can influence element cycling by disrupting microbiomes and benthos. • Effects of microplastics depend on the properties of microplastics and sediment. • The long-term effect of microplastics on element cycling is needed in future. [ABSTRACT FROM AUTHOR]