A Review of Microplastic Identification and Characterization Methods in Aquatic Environments

Plastic waste has become a major global issue, with over 390.7 million tons of plastic produced in 2021. Because of its durability, low recycling rates, poor waste management, and maritime use, a considerable portion of plastic waste ends up in aquatic environments. Photo-oxidation and other mechanisms degrade plastics into microplastics (MPs), which are particles smaller than 5 mm. MPs can spread through the aerial, terrestrial, and aquatic areas, and running waterways serve as conduits for MP transport across various ecosystems. MPs have been found at various levels of the food web, and animals can ingest, inhale, or absorb them through their skin. MPs pose a significant health risk to flora and fauna, including marine creatures and humans, due to their small size, diverse colors, high abundance, and ability to adsorb antibiotic-resistant pathogens, causing cytotoxicity, acute reactions, undesirable immunological responses, neurotoxicity, and DNA alteration. MPs have a negative economic impact on industries such as agriculture, fishing, tourism, etc. Detecting and quantifying the presence of MPs is therefore critical. The purpose of this paper is to provide an overview of the various techniques and equipment used to detect and characterize MPs in aqueous environments. Identifying and educating the public about the primary sources of plastic pollution can help reduce the number of MPs in the environment.