Microplastics and Head and Neck Health: Emerging Implications for Otolaryngologic Disorders and Carcinogenesis

Microplastics (MPs), defined as plastic particles <5 mm in size, have become pervasive environmental contaminants with increasing relevance to human health. While originally investigated in marine environments, MPs are now routinely found in human tissues and fluids—including the blood, lungs, placenta, breast milk, and brain—demonstrating their widespread distribution and capacity for accumulation within the human body. The upper aerodigestive tract (UADT), comprising the nasal cavity, pharynx, larynx, and middle ear, serves as a key entry point for inhaled particles and is therefore particularly susceptible to MP deposition. Despite limited direct research on otolaryngologic tissues, mechanistic similarities with airborne pollutants such as particulate matter (PM<sub>2.5</sub>) suggest that MPs could elicit comparable biological effects, such as disruption of the epithelial barrier, induction of oxidative stress, mucosal inflammation, immune system disturbances, and fibrosis. These pathophysiological changes may play a role in the development of various ENT disorders, including chronic rhinosinusitis, allergic rhinitis, anosmia, and otitis media. Recently, there is increasing speculation that MPs could also contribute to head and neck (HN) carcinogenesis. MPs have been shown to transport adsorbed carcinogens and activate biological pathways including epithelial-mesenchymal transition (EMT), immune evasion, and remodeling of the tumor microenvironment, all of which are integral to tumor initiation, progression, and therapeutic resistance. Although causative associations have not yet been established, their detection in other organ systems susceptible to disease (e.g., lung, brain) further supports the possibility of oncologic implications. This review provides a comprehensive synthesis of existing data on MP exposure, accumulation in tissues, detection technologies, and the potential consequences for ENT health and malignancies of the HN. Drawing from toxicological, immunobiological, and oncological research, we highlight the critical need for systematic investigation of this underrecognized aspect of environmental risk in otolaryngology.