Over the past century and a half, advancements in polymer science—encompassing both natural and synthetic materials—have led to the development of strong, lightweight, and highly flexible polymers. Their remarkable diversity and versatility make them indispensable in modern life. However, the escalating accumulation of fragmented plastic waste in the environment has become a pressing global concern. Micro- and nanoplastics (MNPs), which tend to accumulate at the air-water interface, pose potential safety and security risks by serving as carriers for viruses. Currently, there is limited research on the effects of MNP consumption in both human and non-human models. This book provides a comprehensive examination of the challenges associated with MNPs, their environmental monitoring, and management strategies aimed at risk assessment and mitigation. It explores emerging techniques for identifying, collecting, and mitigating MNP contamination in aquatic ecosystems. Additionally, it delves into the toxicokinetics, fate, and transport of MNPs, including recent findings on their movement within the human body. A notable development in this field is the application of metamaterials for detecting and degrading organic pollutants and microplastics through photocatalysis. From a policy perspective, refining international standards—encompassing product labeling, responsible usage, and strategies for recycling, upcycling, and sustainable disposal—remains imperative for mitigating the long-term impact of MNP pollution.