Toxicity of Microplastics on the Flora and Fauna of the Freshwater Ecosystem: An Overview

Microplastics (MPs) are defined as minute plastic particles that typically exhibit dimensions that span from 1 μm to 5 mm. The aforementioned materials exhibit insolubility in aqueous media and can be subdivided into primary particles, generated initially at diminutive dimensions, and secondary particles, formed as a consequence of the disintegration of larger plastic constituents. Microplastics (MPs) tend to accumulate in various ecosystems, including those of freshwater origin, and subsequently become subject to degradation. Given their omnipresence, freshwater ecosystems represent a paramount facet of human existence and remain persistently vulnerable to the presence of minute plastic particles. MP pollution is regarded as a major global concern in contemporary times due to its detrimental impacts on all facets of the freshwater ecosystem. The deleterious effects are primarily associated with the toxic nature of MPs, which pose a grave threat to the various components of the said environment. The present chapter elucidates upon the subject of freshwater contaminants of emerging concern, specifically with regard to MPs. The toxicity and mechanism of action of these contaminants are comprehensively discussed, along with their biodegradation mechanism. The repercussions of exposure of indigenous aquatic life forms, including autotrophic organisms and flora and fauna within the freshwater environment, are also examined in detail. The degree of toxicity inflicted by microplastics (MPs) is contingent upon the species exposed to MPs, as well as the manner of exposure.