UTTAR PRADESH JOURNAL OF ZOOLOGY

The increased plastic waste has introduced the spread of microplastics and nanoplastics throughout marine ecosystems, posing a multi-faceted, rapidly escalating, and largely unknown threat to the environment and human health. The present review integrates the scientific literature published from 2010 to 2025—synthesizing studies identified through PubMed, Scopus, and Web of Science—to trace the progression from first detections and distributions to mechanistic toxicological research and, most recently, investigations focused on human health risks. We discuss the primary sources and atmospheric fates of marine microplastics, as well as the main patterns of human exposure—ingestion, inhalation, and dermal contact—and the evidence for human tissue accumulation. At the same time, the review meticulously unpacks the cellular and systemic toxicities of MPs and NPs, including central mechanisms such as oxidative stress, inflammation, apoptosis, and genotoxicity, and their relationships to developing chronic conditions such as metabolic disorders, immunodeficiencies, and neurodegenerative diseases. Moreover, the remaining areas of scarce evidence—particularly long-term human epidemiology and human curbing functions—are explored. We conclude by presenting prospective mitigations, including upgraded filtration, novel biohybrid technologies, and potential therapies. This review presents a summary of current knowledge and emphasizes the great urgency of a transdisciplinary, One Health-oriented approach to confront the intricate menace of microplastic contamination.