Association between organophosphate insecticide metabolites and lung function in U.S. adults: NHANES 2011-2012

Humans are frequently exposed to organophosphate insecticides (OPI), yet the impact of these chemicals on lung function remains uncertain.

We will use the National Health and Nutrition Examination Survey to further investigate the association between organophosphate insecticide metabolites and lung function.

This is a cross-sectional study conducted using US population data from the National Health and Nutrition Examination Survey.

We analyzed data from 894 Americans to investigate the association between organophosphate insecticide (OPI) metabolites and pulmonary function tests. In addition, to assess the joint effects of OPI mixtures on lung function, we applied weighted quantile sum (WQS) regression, quantile g-computation (QG-C), and Bayesian Kernel Machine Regression (BKMR).

In this study, we examined the associations between urinary organophosphate insecticide (OPI) metabolites and lung function indicators (FVC, FEV₁, and FEV₁/FVC) in adults. Generalized linear regression analyses showed that a 10-fold increase in dimethylphosphate (DMP) concentration was associated with an average decrease of 1 mL in FVC (β = -0.00057, 95% CI: -0.0030 to 0.0019, p = 0.66) and 1 mL in FEV₁ (β = -0.00048, 95% CI: -0.0024 to 0.0015, p = 0.64), neither of which were statistically significant. A 10-fold increase in diethylphosphate (DEP) concentration was associated with an average increase of 1 mL in FVC (β = 0.0024, 95% CI: -0.00069 to 0.0055, p = 0.13) and 1 mL in FEV₁ (β = 0.0019, 95% CI: -0.00057 to 0.0044, p = 0.13), also not statistically significant. A 10-fold increase in dimethylthiophosphate (DMTP) concentration was associated with an average decrease of 1 mL in FVC (β = -0.00014, 95% CI: -0.0012 to 0.00093, p = 0.79) and 1 mL in FEV₁ (β = -0.00016, 95% CI: -0.0010 to 0.00069, p = 0.72), likewise non-significant. Mixture exposure analyses using WQS, QG-C, and BKMR models indicated that DEP was the primary protective component, showing positive effects on FVC and FEV₁; DMTP was the main risk component, negatively affecting FEV₁; and DMP had minimal influence within the mixture. DEP and DMTP appeared to exert synergistic effects at moderate to high exposure levels, resulting in more pronounced negative impacts on lung function.

In the U.S. adult population, individual exposure to DMP, DEP, or DMTP was not significantly associated with FVC, FEV₁, or FEV₁/FVC in overall linear analyses. Mixture exposure analyses suggested that DEP may exert a protective effect, while DMTP is the primary potential risk factor, with both metabolites potentially exhibiting synergistic effects at moderate to high exposure levels. Overall, urinary OPI metabolites have a limited impact on adult lung function, and most individual exposure effects were not statistically significant.