SOURCE, IDENTIFICATION, DISTRIBUTION, AND ABUNDANCE OF MICROPLASTICS IN RIVERS AND THEIR ECOLOGICAL IMPACTS: A REVIEW

Abstract

Microplastics (MPs) are tiny plastic particles that persist in nature for more than 100 years. This review aimed to illustrate the scenario of global microplastic pollution in various rivers and their ecological impacts. The study collected data from journals, books, and reports published within the last twenty years using multiple search engines such as Google Scholar, ResearchGate, etc. Microplastics (MPs) were found in high abundance in river systems, which act as pathways for from terrestrial to marine ecosystems. FTIR, or Raman spectroscopy, Py-GC-MS, and SEM-EDS were the major instruments to identify MPs. Green or blue-colored fibers or fragments like PE or PP polymers were dominant MPs in rivers. This review found the highest 120 ± 43 MPs/L in water samples collected from Nakdong River, South Korea, whereas the highest 13607 MPs/kg in sediment samples collected from peripheral rivers of Dhaka, Bangladesh, and MPs abundance ranged from 6.3 to 22.21 MPs/fish and 40 MPs/bird. Ingested microplastics can block digestive tracts, reduce nutrient absorption, and lead to starvation, and they can cause exposure to toxins and pathogens. However, it causes bioaccumulation and disrupts food chains and habitats. Therefore, effective mitigation strategies should be adopted to address the microplastic pollution in rivers.