Microplastic contamination, an emerging threat to the freshwater environment: a systematic review

Microplastics have been noticed as widespread in an aquatic environment at the microscale. They have nonstop increased due to the increase in the production of synthetic plastics, population and poor waste management. They are ubiquitous in nature and slowly degrade in water and soil. They are emerging pollutants that have received interest from public audiences and research communities. They have great stability and can adsorb various other pollutants like pesticides, heavy metals, etc. After entering the freshwater environment, microplastics can be stored in the tissue of organisms and stay for a long time. They can generate a serious threat to freshwater ecosystems and can cause physical damage to organisms. Visual identification, Raman spectroscopy, pyrolysis–gas chromatography–mass spectrometry (Pyro–GC–MS), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and combined methods are the commonly known methods for the quantification and identification of microplastics. The detected concentration of microplastics depends on the sampling method, locations and identification techniques. The authors assessed the sources, transport, impacts, identification and characterization, and treatment of microplastics in freshwater environments in detail. The authors are also giving some recommendations for the minimization of the MPs from the freshwater environment. This review article will provide the baseline facts for the investigators to do more research on microplastic pollution in the future.