Emerging Public Health Concerns of Micro- and Nanoplastics in Humans: Detection and Health Impact

Microplastics (MPs) and nanoplastics (NPs) have become pervasive environmental contaminants, raising growing concern regarding their potential accumulation within the human body and associated health risks. MP particles can translocate into systemic circulation and multiple organs, necessitating a comprehensive evaluation of current human biomonitoring data. This comprehensive review aimed to synthesize current evidence on the occurrence, distribution, detection technologies, exposure reduction and potential health implications of microplastics in human biological samples. The reviewed literature confirms the presence of microplastics in blood, placenta, amniotic fluid, umbilical cord blood, breast milk, semen, urine, and selected tissues including cardiovascular, renal, and reproductive samples. Detection frequencies in some matrices exceeded 70–90%, with polymer types such as polyethylene, polypropylene, polystyrene, and polyethylene terephthalate most commonly identified. Reported particle sizes ranged from nanometer-scale fragments to particles over 100 µm, indicating both systemic circulation and potential tissue retention. Spectroscopic techniques such as μFTIR and μRaman dominate polymer identification, while thermoanalytical approaches such as Py-GC/MS provide quantitative polymer confirmation. Emerging evidence suggests associations with oxidative stress, inflammatory responses, endothelial dysfunction, and impaired reproductive parameters, although causal relationships remain uncertain due to methodological heterogeneity and limited longitudinal data. This review provides an integrated overview of current human exposure evidence, identifies analytical gaps, and highlights the urgent need for harmonized detection frameworks and longitudinal risk assessment studies to inform public health policy and future biomonitoring strategies.