Introduction:Per- and Polyfluoroalkyl Substances (PFAS) are widely used chemicals, notably in nonstick coatings, fire-fighting foams and equipment, and surfactants. These chemicals degrade slowly and accumulate in tissues and the environment, being detected in water, air, wildlife, and soil across the world. Initial studies have shown that these chemicals are associated with harmful health effects, but research in this area remains limited, especially in sinonasal diseases. Methods:The National Health and Nutrition Examination Survey (NHANES) 2011-2014 was used to analyze the association between PFAS and taste and smell survey among adults (age≥40) with complete data (n=1911). The survey included self-reported sinonasal symptoms. Multivariable logistic regression adjusted for covariates was used to describe the relationship between serum PFAS concentrations and sinonasal health. Bayesian kernel machine regression (BKMR) was performed to consider the diverse chemical properties of PFAS and how real-life exposures involve multiple types of PFAS. Results:The logistic regression model found that serum PFAS levels were not significantly associated with sinonasal health outcomes, except serum Me-PFOSA-AcOH (OR: 1.164; 95% CI: 1.020, 1.308), which significantly increased the likelihood of reporting frequent nasal congestion in the past 12 months. The BKMR model identified exposure-response relationships on olfaction of Me-FPOSA-AcOH and PFHxS becoming more pronounced as the concentration of PFNA within the mixture increased. Conclusion:Our results highlight a potential relationship between PFAS and adverse sinonasal health effects. Exposure to Me-PFOSA-AcOH may be related to frequent nasal congestion while other PFAS may have complex, mixture-dependent effects on olfaction.