Microplastics in the Human Nasal Cavity and Upper Airway: Emerging Evidence and Rhinologic Implications

Microplastics (MPs) are pervasive environmental contaminants with potential implications for human health. Although inhalation is considered a major route of exposure, most investigations have focused on the lower respiratory tract, leaving the upper airway relatively understudied. Recent studies have detected MPs in nasal lavage fluid, specimens from patients with allergic rhinitis, tissue from patients with chronic rhinosinusitis, and the olfactory bulb of the human brain. Concerns have also been raised that synthetic polymerbased medical devices, including nasal irrigation bottles and continuous positive airway pressure systems, may contribute to upper airway exposure. This review summarizes current evidence on the detection and characterization of MPs in the human nasal cavity and upper airway, discusses environmental and medical device-related exposure pathways, and examines emerging implications for rhinologic diseases. Methodological limitations and priorities for future research are also reviewed.