Association of perfluoroalkyl substances with pulmonary function in adolescents (NHANES 2007-2012)

Perfluoroalkyl substances (PFASs) constitute an environmentally persistent and widespread class of anthropogenic chemicals that have been used in industrial and commercial applications in the USA and around the world. Animal studies suggested its toxic impact on lung development, but the adverse effect of PFAS exposure on childhood pulmonary function has not been clearly determined. We investigated the potential cross-sectional association of environmental PFAS exposures with pulmonary function in 765 adolescents aged 12-19 years from the US National Health and Nutrition Examination Survey (NHANES) 2007-2012. Exposure to PFASs was estimated by measuring serum concentrations, and pulmonary function was assessed by spirometry. Linear regression and weighted quantile sum (WQS) regression were performed to estimate the associations of individual chemicals and chemical mixtures with pulmonary function. Median concentrations of PFOA, PFOS, PFNA, and PFHxS (detection frequencies > 90%) were 2.70, 6.40, 0.98, and 1.51 ng/mL, respectively. No associations were found between the four individual congeners and Σ₄PFASs and the pulmonary function measures in total adolescents. Sensitive analyses were further conducted stratified by age (12-15 and 16-19 years) and sex (boys and girls). In adolescents aged 12-15 years, PFNA was negatively associated with FEV₁:FVC (p-trend = 0.007) and FEF_25-75% (p-trend = 0.03) among girls, while PFNA was positively associated with FEV₁: FVC (p-trend = 0.018) among boys. No associations were found among adolescents aged 16-19 years, either boys or girls. The aforementioned associations were confirmed when further applying WQS models, and PFNA was identified to be the most heavily weighing chemical. Our results suggested that environmental exposure to PFNA may affect pulmonary function among adolescents aged 12-15 years. Given the cross-sectional analysis and less consistent results, further replications of the association in large prospective cohort studies are warranted.