Microplastics in the Ecosystem: An Overview on Detection, Removal, Toxicity Assessment, and Control Release

In recent decades, the accumulation and fragmentation of plastics on the surface of the planet have caused several long-term climatic and health risks. Plastic materials, specifically microplastics (MPs;sizes < 5 mm), have gained significant interest in the global scientific fraternity due to their bioaccumulation, non-biodegradability, and ecotoxicological effects on living organisms. This study explains how microplastics are generated, transported, and disposed of in the environment based on their sources and physicochemical properties. Additionally, the study also examines the impact of COVID-19 on global plastic waste production. The physical and chemical techniques such as SEM-EDX, PLM, FTIR, Raman, TG-DSC, and GC-MS that are employed for the quantification and identification of MPs are discussed. This paper provides insight into conventional and advanced methods applied for microplastic removal from aquatic systems. The finding of this review helps to gain a deeper understanding of research on the toxicity of microplastics on humans, aquatic organisms, and soil ecosystems. Further, the efforts and measures that have been enforced globally to combat MP waste have been highlighted and need to be explored to reduce its potential risk in the future. © 2022 by the authors.

Adsorption of environmental contaminants on micro- and nano-scale plastic polymers and the influence of weathering processes on their adsorptive attributes.

Increases in plastic-related pollution and their weathering can be a serious threat to environmental sustainability and human health, especially during the present COVID-19 (SARS-CoV-2 coronavirus) pandemic. Planetary risks of plastic waste disposed from diverse sources are exacerbated by the weathering-driven alterations in their physical-chemical attributes and presence of hazardous pollutants mediated through adsorption. Besides, plastic polymers act as vectors of toxic chemical contaminants and pathogenic microbes through sorption onto the 'plastisphere' (i.e., plastic-microbe/biofilm-environment interface). In this review, the effects of weathering-driven alterations on the plastisphere are addressed in relation to the fate/cycling of environmental contaminants along with the sorption/desorption dynamics of micro-/nano-scale plastic (MPs/NPs) polymers for emerging contaminants (e.g., endocrine-disrupting chemicals (EDCs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pharmaceuticals and personal care products (PPCPs), and certain heavy metals). The weathering processes, pathways, and mechanisms governing the adsorption of specific environmental pollutants on MPs/NPs surface are thus evaluated in relation to the physicochemical alterations based on several kinetic and isotherm studies. Consequently, the detailed evaluation on the role of the complex associations between weathering and physicochemical properties of plastics should help us gain a better knowledge with respect to the transport, behavior, fate, and toxicological chemistry of plastics along with the proper tactics for their sustainable remediation.