Prenatal Ambient Air Pollutant Mixture Exposure and Early School-age Lung Function

Hsiao-Hsien Leon Hsu; Ander Wilson; Joel Schwartz; Itai Kloog; Robert O Wright; Brent A Coull; Rosalind J Wright

doi:10.1097/EE9.0000000000000249

Prenatal Ambient Air Pollutant Mixture Exposure and Early School-age Lung Function

Environ Epidemiol. 2023 Apr 4;7(2):e249. doi: 10.1097/EE9.0000000000000249. eCollection 2023 Apr.

Authors

Hsiao-Hsien Leon Hsu^{1

2}, Ander Wilson³, Joel Schwartz⁴, Itai Kloog^{1

2}, Robert O Wright^{1

2}, Brent A Coull⁵, Rosalind J Wright^{1

2}

Affiliations

¹ Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
² Institute for Exposomic Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
³ Department of Statistics, Colorado State University, Fort Collins, CO, USA.
⁴ Department of Environmental Health, TH Chan School of Public Health, Harvard University, Boston, MA, USA.
⁵ Department of Biostatistics, TH Chan School of Public Health, Harvard University, Boston, MA, USA.

Abstract

Research linking prenatal ambient air pollution with childhood lung function has largely considered one pollutant at a time. Real-life exposure is to mixtures of pollutants and their chemical components; not considering joint effects/effect modification by co-exposures contributes to misleading results.

Methods: Analyses included 198 mother-child dyads recruited from two hospitals and affiliated community health centers in Boston, Massachusetts, USA. Daily prenatal pollutant exposures were estimated using satellite-based hybrid chemical-transport models, including nitrogen dioxide(NO₂), ozone(O₃), and fine particle constituents (elemental carbon [EC], organic carbon [OC], nitrate [NO₃ ^-], sulfate [SO₄ ^2-], and ammonium [NH₄ ⁺]). Spirometry was performed at age 6.99 ± 0.89 years; forced expiratory volume in 1s (FEV₁), forced vital capacity (FVC), and forced mid-expiratory flow (FEF_25-75) z-scores accounted for age, sex, height, and race/ethnicity. We examined associations between weekly-averaged prenatal pollution mixture levels and outcomes using Bayesian Kernel Machine Regression-Distributed Lag Models (BKMR-DLMs) to identify susceptibility windows for each component and estimate a potentially complex mixture exposure-response relationship including nonlinear effects and interactions among exposures. We also performed linear regression models using time-weighted-mixture component levels derived by BKMR-DLMs adjusting for maternal age, education, perinatal smoking, and temperature.

Results: Most mothers were Hispanic (63%) or Black (21%) with ≤12 years of education (67%). BKMR-DLMs identified a significant effect for O₃ exposure at 18-22 weeks gestation predicting lower FEV₁/FVC. Linear regression identified significant associations for O_3, NH₄ ⁺, and OC with decreased FEV₁/FVC, FEV₁, and FEF_25-75, respectively. There was no evidence of interactions among pollutants.

Conclusions: In this multi-pollutant model, prenatal O₃, OC, and NH₄ ⁺ were most strongly associated with reduced early childhood lung function.

Keywords: Lung function; Mixture; Multi-pollutant; Prenatal exposure; spirometry.

Abstract

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