The Invisible Intruder: a Review of Microplastics Accumulation in Human Tissues and Implications for Public Health, with Emphasis on Reproductive Health

Global plastic production has led to widespread environmental contamination, with synthetic polymers fragmenting into microplastics (MPs) and nanoplastics (NPs). These particles have been detected in human tissues, raising questions about their health effects. This narrative review synthesizes biomonitoring studies on MP/NP accumulation, with a focus on reproductive systems. Data from recent research show polymers in blood, lungs, placentas, breast milk, testes, and brain, linked to exposure routes such as inhalation and ingestion. The review examines potential translocation across barriers like the placenta and blood-brain barrier, as well as toxicity mechanisms, including endocrine-disrupting chemical release, oxidative stress via the Nrf2 pathway, and cellular disruption. In reproductive health, evidence indicates MP presence in ovarian follicular fluid and associations with reduced sperm quality, suggesting potential contributions to fertility trends. The review also addresses debates on neuro-accumulation and economic costs of related diseases. Findings highlight MPs as a public health concern, calling for policy measures and updated risk assessments.