First Report of Occurrence, Distribution, and Characterization of Macro- and Microplastics in the Freshwater: a Case Study on Sarab Niloofar Lake, Kermanshah, Iran.

In this study, for the first-time research has been conducted on the macro- (>2 cm) and microplastics (MPs, <5 mm) abundance in the freshwater of Sarab Niloofar Lake, Kermanshah, Iran. The selected MPs were characterized by FTIR, SEM, and EDX. The results revealed that the abundance of MPs was ranged from 4400 to 18,800 particles/m³, and significant differences (p<0.002) in MPs abundance among the sampling stations were also observed. The high frequency of MPs in the term of shapes was related to fibers (68%), film (23%), fragment (9%), respectively, mostly black (52%), and blue (24%). Moreover, the majority of MPs (65%) had a size range between 0.025 and 1 mm (25–1000 μm). The results of polymer composition by the FT-IR analysis confirmed that polypropylene (PP) and polyethylene (PE) were dominant. Moreover, the presence of specific metals (especially Al, Si, and Ca) on the MPs surface, confirming the interactions between the MPs and the aquatic environment. As a result of this study, the mean level (±SD) of macro- and microplastics in the freshwater was determined to be 178.2 ± 77.024 particles/m² and 10175 ± 4958.019 particles/m³, respectively. All in all, the results of this work showed that this lake is highly polluted by plastic particles, consequently stringent management strategies for the understanding the sources, transport ways, and adverse effects of plastic pollution on the aquatic in this area must be taken. [ABSTRACT FROM AUTHOR]