Organophosphate esters, airway inflammation, and lung function among US participants: A nationally representative cross-sectional study from NHANES, 2011-2012

Background: Human beings are widespread exposed to organophosphate esters (OPEs), but little is known about their effects on respiratory health. Objectives: To investigate the associations of exposure to OPEs with lung function and airway inflammation among U.S. participants from NHANES, 2011-2012. Methods: A total of 1636 participants aged 6-79 years were included. Concentrations of OPE metabolites were mea-sured in urine and lung function was assessed with spirometry. Fractional exhaled nitric oxide (FeNO) and blood eo-sinophils (B-Eos), two important inflammatory biomarkers, were also measured. Linear regression was performed to examine the relationships of OPEs with FeNO, B-Eos and lung function. Bayesian kernel machine regression (BKMR) was used to evaluate the joint associations between OPEs mixtures and lung function. Results: Three of seven OPE metabolites had detection frequencies > 80 %, including diphenyl phosphate (DPHP), bis (1,3-dichloro-2-propyl) phosphate (BDCPP), bis-2-chloroethyl phosphate (BCEP). A 10-fold increase in DPHP concen-trations were associated with 1.02 mL decreases in FEV1 (j3 = -0.01, 95 % CIs = -0.02, -0.003) and FVC (j3 = - 0.01, 95 % CIs = -0.02, -0.003), respectively, and the similar, modest decreases were seen for BDCPP. For each 10-fold increase in BCEP concentration, FVC was also reduced by 1.02 mL (j3 = -0.01, 95 % CIs = -0.02, - 0.002). Moreover, the negative associations were only found in non-smokers aged >35 years. The aforementioned associations were confirmed by BKMR, but we cannot definitively identify a constituent driving this association. B-Eos

Automated summary

This study investigated the associations between exposure to organophosphate esters (OPEs) and lung function and airway inflammation among US NHANES participants (2011-2012). The results showed that higher concentrations of OPEs were associated with decreased lung function, especially in non-smokers aged over 35.