Microplastics and Human Health: Exposure Pathways, Contributive Roles, and Mitigation Strategies

The sophistication of human life with the inventions and infrastructure development that followed the industrial revolution has one unintended consequence—plastic pollution. Their exponential growth, accumulation in all the environmental systems, persistence and low rate of decay have made them unique polluters of this century, to which no wise management practices and mitigation strategies are known currently. The micro/nano sizes of plastic debris not only concerned in the natural environment; they also possess emergency risks to human health. Through an extensive literature search, we retrieved a total of 4583 records from the Scopus database appeared in last decade (2016–2025). By adopting PRISMA guidelines, we selected 932 literatures for extensive scoping review of the exposure pathways and mechanistic evidence linking microplastics to human health. The review has synthesized the evidences on microplastics contamination of external and internal human systems and traced the occurrence, types, abundance, distribution, and modes of transportation and bioaccumulation reported in the literature. The dominant mode of microplastics transport includes ingestion, followed by inhalation, dermal contact, and injection. Translocation of microplastics through circulatory systems within the human body endangers vital organs including brain and placental tissues, raising concern about potential systemic health risks. Review and examination of the microplastics exposure to humans with reference to the relative vulnerabilities of various organs revealed that, the gastrointestinal tract-digestive system, followed by liver-hepatic system, kidney-renal system, lungs-respiratory system, brain and nerves-the nervous system, reproductive system, cardiovascular and circulatory system, skin-integumentary system and lymphoid organs and tissues-immune system are all prone to microplastic-nanoplastic contaminants and are subjected to various levels of threats. Owing to their bioaccumulation capacity, slow rate of decay and persistence in almost all the media, effective mitigation/management strategies are yet to be devised and their effectiveness in tackling the menace is validated. With about 50 primary types of polymers, producing over 60,000 formulations, at an approximate rate of 8% increase every year, result in an alarming rate of plastic refuse in natural environments, often unmanaged is a looming threat to environmental systems and ecological niches. Addressing this situation requires urgent, policy initiatives, and microscale management practices, that include plans and strategies for source reduction, environmental intervention, legal and mandatory management/reuse/recycle practices at microscale.