Understanding the Nexus Between Microplastics and Human Health: A Narrative Review

ABSTRACT Microplastics (MPs) are widespread pollutants that infiltrate ecosystems, food sources, and, increasingly, human tissues. Their persistence and small size facilitate entry into the human body via food, water, and inhaled air. Recognizing the health implications, this review explores the MPs pathways and impacts, from environmental distribution to mechanisms affecting human health. Through a comprehensive assessment of papers published up to October of 2025 across Scopus, PubMed, WoS, JSTOR, and Google Scholar, we synthesize current literature on MPs exposure routes and recent findings on their presence in tissues, including the skin, lungs, liver, and reproductive organs. Mechanistic insights implicate inflammation, oxidative stress, genotoxicity, mitochondrial dysfunction, and endocrine disruption as potential modes of toxicity. However, most data derive from in vitro or animal models, with limited human‐specific validation. Evidence linking MP exposure to disease outcomes remains preliminary and heterogeneous, constrained by inconsistent metrics, lack of standardized reference materials, and small sample sizes. Evidence confidence varies across tissues; the placenta and feces show high confidence, whereas others, such as penile and heart tissue, show low confidence. Although MPs’ capacity to act as vectors for contaminants and pathogens heightens concern, the magnitude of these risks in human populations is not yet quantifiable. This review identifies methodological gaps that hinder clinical risk characterization and emphasizes the need for harmonized analytical protocols, longitudinal epidemiological studies, and coordinated regulatory frameworks. By critically appraising current evidence, we aim to clarify what is known, what remains uncertain, and which research priorities are most urgent to inform effective public health interventions.