Prenatal exposure to a mixture of per- and polyfluoroalkyl substances (PFAS) and lung function and immune-related outcomes among males in childhood and young adulthood.

Background: Prenatal exposure to per- and polyfluoroalkyl substances (PFAS) may influence lung and immune system development, but previous epidemiological studies are inconclusive and have not extended into young adulthood.

Objective: To examine associations between prenatal exposure to a mixture of PFAS and respiratory and immune-related outcomes in a cohort of males.

Methods: We studied 866 males with maternal pregnancy plasma measured for 15 PFAS, triclosan, and nine phthalate metabolites used as a proxy for prenatal exposure. Spirometry was measured at approximately age 19 years. Asthma in young adulthood was reported in questionnaires at age 18 years. Asthma, hay fever, and eczema at 7 and 11 years of age were based on parental reports. We estimated the difference in spirometry measures and odds ratios (ORs) for questionnaire outcomes per one-interquartile range (IQR) increase in a mixture of seven well-detected PFAS using quantile g-computation models. Subsequently, we examined a mixture of seven PFAS, two phthalate metabolites and triclosan, and ran single-pollutant analyses.

Results: A one-IQR increase in the PFAS mixture was associated with lower forced expiratory volume in one second (FEV) and forced vital capacity (FVC) (milliliter difference [95% CI]: -85 [-160;-9], -88 [-173;-3], respectively), but not FEV/FVC. Higher concentration of the PFAS mixture was also associated with lower odds of a history of and current hay fever (OR [95% CI]: 0.52 [0.34;0.80], 0.49 [0.30;0.81], respectively), but not asthma or eczema. Associations did not change substantially when including phthalate metabolites and triclosan to the PFAS mixture and single-pollutant analyses were overall consistent with mixture analyses.

Conclusion: Prenatal PFAS exposure was associated with lower FEV and FVC in a cohort of young adult males, suggesting an impact on lung development. Associations with reduced hay fever in childhood may suggest influences on immune maturation. Potential sex-specific effects should be addressed in future studies.