Evidence of microplastics in wetlands: Extraction and quantification in Freshwater and coastal ecosystems

Microplastics are the emerging non-degradable pollutants in natural ecosystems. It impacts humans and wildlife, mainly aquatic species, by getting incorporated into the food chain due to their sizes (< 5 mm). Micmplastics are common in the marine ecosystems but are also present in the freshwater ecosystems, such as in lakes, ponds, river basins, wetlands, or even in moist agricultural lands and groundwater. This paper focuses on the primary sources, detection, and quantification of micmplastics in wetlands, both freshwater and coastal, based on research conducted worldwide. Fibers (thread), fragments, filaments, foams, and micmbeads are common shapes of microplastics observed in wetland ecosystems. Microplastics pollution has been observed in wetlands with an abundance of up to 5531 particles m(-3) and 6360 particles kg(-1) in water and sediment samples, respectively. This study also discusses the recent progress in extraction, characterization, and quantification techniques in order to identify research gaps, such as the interaction of microplastic and heavy metals and organic compounds in the wetland ecosystem. Microplastics in size range of 0.12-9.5 mm have been reported in wetland biota. Furthermore, ecological concerns are identified in terms of threats and disturbances caused by micmplastics to the freshwater organisms present in wetlands. Finally, it outlines the future scope, research gap, and potential solutions for microplastic pollution research in wetlands.