Environmental Exposures, Chronic Sinusitis, and Olfaction in People With Cystic Fibrosis.

Environmental air pollutants may contribute to chronic rhinosinusitis (CRS), but their relationship with upper airway disease in people with cystic fibrosis (CF) remains poorly understood. This study evaluated associations between long-term ambient air pollutant exposure and CRS severity and olfactory dysfunction in adults with CF and CRS. 80 adults with CF and comorbid CRS were prospectively enrolled from 2019 to 2023 at multiple U.S. academic rhinology centers. Long-term exposure to PM2.5, PM10, CO, SO2, NO2, and ozone was estimated using the nearest U.S. Environmental Protection Agency monitor linked to each participant's residential ZIP code, with 3-year mean exposure calculated before enrollment. CRS severity and olfaction were assessed using Lund-Kennedy endoscopy scores, Lund-Mackay CT scores, SNOT-22, Questionnaire of Olfactory Disorders-Negative Statements, and 40-item Smell Identification Test. Analyses used Spearman correlations and nonparametric group comparisons. Higher ozone exposure was associated with worse total SNOT-22 scores (Rs = 0.34 p = 0.002), including ear/facial, psychological, and sleep dysfunction domains, as well as worse olfactory-specific outcomes, including higher QOD-NS scores (Rs = 0.30, p = 0.007) and lower Smell Identification Test scores (Rs = -0.30, p = 0.018). Other pollutants did not show significant associations with CRS or olfactory outcomes. In adults with CF and CRS, higher long-term ambient ozone exposure was associated with greater sinonasal symptom burden and worse olfactory function. These findings suggest that ozone may be an environmental contributor to upper airway disease severity in this population and support further study in larger, adjusted analyses. Increased ozone pollution correlates with more severe CRS in people with CF. Among people with CF and CRS, higher ozone exposure is associated with worse olfactory function.