Occurrence and distribution of micro- and mesoplastics in the high-latitude nature reserve, northern China

Abstract

Microplastics pollution has received growing attention worldwide in recent years. However, data on microplastics in the freshwater environment are still limited, especially in high-latitude nature reserves in Northern China. The first study on microplastic pollution in the Liaohe River Reserve in Northern China is reported here, and mesoplastics were also incorporated. Surface water and sediment samples were collected from 32 sites along the nature reserve. The abundance, type, shape, color, and size of micro-and mesoplastics were measured using density extraction, optical microscopy, and FTIR spectroscopy. The data showed that diverse micro-and mesoplastics were found widespread in the 32 sites, and the average abundance of these plastics was 0.11AE0.04 10 -2 items/L in surface water and 62.29AE54.30 items/kg in sediment. Moreover, 70% and 66% were smaller than 2000 μm in surface water and sediment, respectively. Fiber accounted for 91.86% in surface water and 43.48% in sediment, indicating that the major source of micro-and mesoplastics in the Liaohe River Reserve may be domestic sewage and aquaculture. A total of 16 and 27 polymers were identified in surface water and sediment, respectively, and mostly consisted of rayon, polyester, polystyrene, and poly(ethylene terephthalate). Moreover, both the risk index and the pollution load index demonstrated a low risk of micro-and mesoplastics in surface water and sediment in the Liaohe River Reserve.

Differentiating Microplastics from Natural Particles in Aqueous Suspensions Using Flow Cytometry with Machine Learning

“…Freshwater systems link terrestrial sources of plastics pollution and the ocean, which highlights their significance in understanding the associated transport pathways of microplastics (MPs). 1,2 MPs (<5 mm in size) enter the environment either directly (primary MPs) or are generated through the fragmentation of macroplastics due to physical and chemical weathering processes (secondary MPs). 3 Currently, there are no standardized approaches to measure MPs, and monitoring MPs in freshwater can be challenging.…”

“…Freshwater systems link terrestrial sources of plastics pollution and the ocean, which highlights their significance in understanding the associated transport pathways of microplastics (MPs). , MPs (<5 mm in size) enter the environment either directly (primary MPs) or are generated through the fragmentation of macroplastics due to physical and chemical weathering processes (secondary MPs) . Currently, there are no standardized approaches to measure MPs, and monitoring MPs in freshwater can be challenging. , Complicating their identification in complex environmental matrices further, MPs in freshwater are often suspended with other particulate matter in the water column, surrounded by an ecocorona of biomacromolecules on their surface, or incorporated with biofilms on stream and river beds. , Given that MPs are a diverse suite of contaminants, the reliable identification and quantification of MPs necessitates advanced analytical methods and robust reference libraries.…”