Does the use of continuous positive airway pressure devices pose a risk of microplastic exposure to the upper airway? A pilot study

Microplastics (MPs) are ubiquitous environmental pollutants that have raised growing concerns about their potential impact on human health. Components used in continuous positive airway pressure (CPAP) devices may degrade into MPs, which could be inhaled during therapy. Deposits of MPs on mucosal surfaces may cause mechanical or chemical irritation, including the release of toxic compounds that stimulate cytokine production. This study aimed to assess whether patients with obstructive sleep apnea (OSA) who regularly use CPAP are exposed to higher levels of inhaled MPs compared to those who have not initiated CPAP therapy. We also explored associations between inhaled MPs and inflammatory biomarkers in the upper airways. Nasal lavage fluid samples from 42 patients with OSA (21 CPAP users, and 21 non-users, all without signs or symptoms of nasal inflammation) were analyzed for MPs and inflammatory markers. MPs were detected in all samples, with no significant difference in total MP counts between groups ( p  = 0.68). Polyethylene and polyamide were the predominant polymers recovered in both groups (around ≥ 80%). Ethylene vinyl acetate (EVA) was the only one of 15 identified polymers to show higher concentration in the CPAP group ( p  = 0.003). Total MPs counts were positively associated with all cytokines, with Interleukin-1 beta and Interleukin-6 showing the strongest associations. In this pilot study, regular CPAP use does not appear to associate with an increase in inhaled microplastic levels in patients with OSA. However, inhaled microplastics were positively associated with elevated inflammatory biomarkers in the upper airways. Current Knowledge : Microplastics (MPs) are pervasive environmental pollutants that can accumulate in human tissues, raising health concerns. Given that CPAP devices may degrade into MPs, daily CPAP therapy may expose patients’ airways to MP accumulation and possibly inflammation. Study Impact : This pioneering study found that regular CPAP use does not appear to elevate inhaled MP levels in the upper airway. However, it revealed a significant positive association between inhaled MPs and elevated inflammatory biomarkers in the upper airways, pointing to potential health implications of MPs. The online version contains supplementary material available at 10.1007/s44470-025-00021-3.