Relationship between perfluoroalkyl substance exposure and immunoglobulin E among Korean adults from Korean National Environmental Health Survey cycle 4 (2018–2020): a cross-sectional study

Introduction The potential immunotoxicity of per- and polyfluoroalkyl substances (PFAS) is a growing public health concern, yet epidemiological evidence in adults remains inconsistent. This inconsistency may partly stem from relying on single-pollutant models that do not fully capture the dynamics of chemical mixtures. Methods We investigated the association between concurrent exposure to a mixture of five PFAS congeners and serum total immunoglobulin E (IgE) levels in a representative sample of 2,987 Korean adults from the 4th Korean National Environmental Health Survey (2018-2020). We employed Weighted Quantile Sum (WQS) regression, Quantile g-computation (Qgcomp), and Restricted Cubic Spline (RCS) analysis to assess mixture effects and non-linear associations. Results A statistically significant positive association was identified between the overall PFAS mixture and total IgE levels ( β = 0.033, p = 0.026), with perfluorodecanoic acid (PFDeA) being the major contributor. RCS analysis revealed a distinct J-shaped, non-linear dose-response relationship between PFDeA and IgE (P non-linear < 0.001). Furthermore, a significant interaction with smoking status was identified ( p < 0.001); the positive association was significant only among non-smokers. Discussion/Conclusion Exposure to long-chain PFAS mixtures is positively associated with atopic tendencies in adults. These findings highlight the importance of mixture modeling and lifestyle stratification in environmental epidemiology.