Impact of polyfluoroalkyl chemicals and volatile organic compounds exposure on lung function of American adults.

Background: Environmental chemicals, such as Perfluoroalkyl and polyfluoroalkyl substances (PFAS) and volatile organic compounds (VOCs), and the association between the combined exposure of these chemicals and human lung function remains unclear. This study aimed to explore the effects of mixed exposure to PFAS and VOCs on lung function in the general population of the United States and investigate their potential mechanisms.

Methods: Data from 30442 respondents were selected for analysis during the US National Health and Nutrition Examination Survey (NHANES) database from 2007 to 2012. Linear models, weighted quantile (WQS) regression, quantile g calculation (QGC), and Bayesian kernel machine regression (BKMR) were used to evaluate the contribution of individual components. Moreover, the interactions between substances in the dose-response relationship mixture of multiple environmental chemical exposures and lung function were also evaluated. The Benjamini-Hochberg method was used to correct multiple tests.

Findings: Univariate analysis showed that nitromethane was negatively correlated with FEV1 (β =-0.052), FVC (β =-0.056), and PEF (β =-0.065), while perfluorohexanesulfonic acid was positively associated with FEV1 (β = 0.026), FVC (β = 0.024), FEF25-75% (β = 0.012), and PEF (β = 0.029). Multivariate analysis showed that chloroform and perfluorohexane sulfonic acid were positively associated with lung function (P <0.05), and perfluorohexane sulfonic acid contributed the most. Nitromethane and perfluorodecanoic acid were negatively associated with lung function (P < 0.05), and perfluorodecanoic acid contributed the highest weight in the negative direction. When all chemicals were in the 50th percentile, the environmental chemical mixture had no significant consistent effect or dose-response on lung function. There were interactions among various environmental chemicals within the mixture except for 2-N-methyl-PFOSA acetate and bromodichloromethane.

Interpretation: These results suggest that environmental mixture exposure is associated with abnormal lung function in American adults, and the interaction of various substances in the mixture affects its physiological and chemical effects.