Intrauterine and early postnatal exposure to outdoor air pollution and lung function at preschool age

Abstract

Background Effects of prenatal and postnatal exposure to air pollution on lung function at preschool age remain unexplored. We examined the association of exposure to air pollution during specific trimesters of pregnancy and postnatal life with lung function in preschoolers. Methods Lung function was assessed with spirometry in preschoolers aged 4.5 years (n=620) participating in the INfancia y Medio Ambiente (INMA) cohort. Temporally adjusted land use regression (LUR) models were applied to estimate individual residential exposures to benzene and nitrogen dioxide (NO 2 ) during specific trimesters of pregnancy and early postnatal life (the first year of life). Recent and current (1 year and 1 week before lung function testing, respectively) exposures to NO 2 and nitrogen oxides (NO x ) were also assessed. Results Exposure to higher levels of benzene and NO 2 during pregnancy was associated with reduced lung function. FEV 1 estimates for an IQR increase in exposures during the second trimester of pregnancy were −18.4 mL, 95% CI −34.8 to −2.1 for benzene and −28.0 mL, 95% CI −52.9 to −3.2 for NO 2 . Relative risk (RR) of low lung function (<80% of predicted FEV 1 ) for an IQR increase in benzene and NO 2 during the second trimester of pregnancy were 1.22, 95% CI 1.02 to 1.46 and 1.30, 95% CI 0.97 to 1.76, respectively. Associations for early postnatal, recent and current exposures were not statistically significant. Stronger associations appeared among allergic children and those of lower social class. Conclusions Prenatal exposure to residential trafficrelated air pollution may result in long-term lung function deficits at preschool age.

Susceptibility Factors Relevant for the Association Between Long-Term Air Pollution Exposure and Incident Asthma

“…However it is of special interest that one study reported higher incidence of asthma in children (even if only boys) who were more exposed in utero during 12-26 weeks of gestation pointing out to a possible prenatal susceptibility window [19]. This result is concordant with a study that found that prenatal exposure to air pollution was associated with long-term lung function deficits at preschool age [44].…”

Birth Weight and Lung Function in Adulthood: A Systematic Review and Meta-analysis

“…Convincing evidence supports the notion that factors affecting intrauterine and early life can influence lung function in adulthood (1)(2)(3). Thirty years ago, Barker and colleagues showed a geographical relationship between high mortality from pneumonia and bronchitis in early life and mortality from chronic lung disease half a century later (4).…”

Exposure to outdoor air pollution during trimesters of pregnancy and childhood asthma, allergic rhinitis, and eczema

“…An INMA cohort study also found the association with LRTI, bronchiolitis, bronchitis, wheezing and persistent cough varied in different prenatal periods, although it was not statistically significant (Esplugues et al, 2011). The recent INMA cohort study found that in utero exposures, more specifically during the second trimester of pregnancy, may be more relevant for long-term adverse consequences for lung function than exposures later in life (Morales et al, 2015). A USA cohort study of 232 asthmatic children indicated that the association between allergic sensitization at 6-11 years of age and exposure to air pollution during pregnancy was stronger in the first and second trimesters (Mortimer et al, 2008).…”