Prenatal exposure to perfluoralkyl substances (PFASs) associated with respiratory tract infections but not allergy- and asthma-related health outcomes in childhood

Background-Prenatal exposure to perfluoralkyl substances (PFASs) has been reported to be associated with immunosuppression in early childhood, but with contradictory findings related to atopic and lung diseases. Aim: We aimed to determine if prenatal exposure to PFASs is associated with asthma or other allergic diseases or respiratory tract infections in childhood. Methods: Nineteen PFASs were measured in cord blood available from 641 infants in the Environment and Childhood Asthma (ECA) prospective birth cohort study. The six most abundant PFASs were perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonamide (PFOSA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUnDA). Health outcomes were assessed at two and ten years of age, and included reported obstructive airways disease (wheeze by 10 years; asthma by 2 and 10 years; reduced lung function at birth; allergic rhinitis by 10 years), atopic dermatitis (AD) by 2 and 10 years, allergic sensitization by 10 years, and episodes of common respiratory tract infections (common cold by 2 years, lower respiratory tract infections (LRTI) by 10 years). The associations between exposure and health outcomes were examined using logistic and Poisson regression. Results: The number of reported airways infections were significantly associated with cord blood concentrations of PFAS; common colds by two years with PFUnDA (beta = 0.11 (0.08-0.14)) and LATIs from 0 to 10 years of age with PFOS (beta = 0.50 (0.42-0.57)), PFOA (beta = 0.28 (0.22-0.35)), PFOSA (beta = 0.10 (0.06-0.14)), PFNA (beta = 0.09 (0.03-0.14)) and PFUnDA (beta = 0.18 (0.13-0.23)) concentrations. Neither reduced lung function at birth, asthma, allergic rhinitis, AD nor allergic sensitization were significantly associated with any of the PFASs. Conclusion: Although prenatal exposure to PFASs was not associated with atopic or lung manifestations by 10 years of age, several PFASs were associated with an increased number of respiratory tract infections in the first 10 years of life, suggesting immunosuppressive effects of PFASs.