The Silent Conquest: The Journey of Micro- and Nanoplastics Through Children's Organs.

Micro- and nanoplastics (MNPs) are emerging environmental contaminants with increasing evidence of bioaccumulation in human tissues and potential toxicological effects. While extensive studies in the literature have investigated MNP exposure and health risks in adult populations, data specific to pediatric age remain scarce and fragmented. This narrative review represents the first integrated synthesis of current evidence on MNP exposure during early life, including the critical period of the first 1000 days, examining routes of absorption (oral, inhalational, dermal, and iatrogenic), biological distribution, and organ-specific effects in infants and children. Special attention is given to the presence of MNPs in pediatric lungs, thyroid, and intestinal microbiota, as well as to emerging non-invasive biomarkers for exposure assessment. The developing physiology of children, characterized by immature detoxification systems, critical windows of vulnerability, and prolonged life-course exposure, amplifies concern for long-term health consequences, including endocrine disruption, immune dysregulation, and neurodevelopmental impairment. This work fills a critical knowledge gap by consolidating pediatric data into a single comprehensive resource, and it is intended to serve both as a reference point for clinicians and researchers and a catalyst for future studies aimed at safeguarding child health in an increasingly plastic-contaminated world.