Prenatal nitrate air pollution exposure and reduced child lung function: Timing and fetal sex effects

Environ Res. 2018 Nov;167:591-597. doi: 10.1016/j.envres.2018.08.019. Epub 2018 Aug 16.

Abstract

Background: Prenatal particulate air pollution exposure may alter lung growth and development in utero in a time-sensitive and sex-specific manner, resulting in reduced lung function in childhood. Such relationships have not been examined for nitrate (NO3-).

Methods: We implemented Bayesian distributed lag interaction models (BDLIMs) to identify sensitive prenatal windows for the influence of NO3- on lung function at age 7 years, assessing effect modification by fetal sex. Analyses included 191 mother-child dyads. Daily ambient NO3- exposure over pregnancy was estimated using a hybrid chemical transport (Geos-Chem)/land-use regression model. Spirometry was performed at mean (SD) age of 6.99 (0.89) years, with forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) z-scores accounting for child age, sex, height and race/ethnicity.

Results: Most mothers were Hispanic (65%) or Black (22%), had ≤ high school education (67%), and never smoked (71%); 17% children had asthma. BDILMs adjusted for maternal age and education and child's asthma identified an early sensitive window of 6-12 weeks gestation, during which increased NO3- was significantly associated with reduced FEV1 z-scores specifically among boys. BDLIM analyses demonstrated similar sex-specific patterns for FVC.

Conclusion: Early gestational NO3- exposure is associated with reduced child lung function, especially in boys.

Keywords: Air pollution; Child; Lung function; Nitrate; Prenatal.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Air Pollution* / adverse effects
  • Bayes Theorem
  • Child
  • Female
  • Forced Expiratory Volume
  • Humans
  • Lung
  • Male
  • Pregnancy
  • Prenatal Exposure Delayed Effects* / epidemiology
  • Vital Capacity