title: Prenatal exposure to residential air pollution and infant mental development: modulation by antioxidants and detoxification factors.
abstract: BACKGROUND
  Air pollution effects on children's neurodevelopment have recently been suggested to occur most likely through the oxidative stress pathway.
  
  
  OBJECTIVE
  We aimed to assess whether prenatal exposure to residential air pollution is associated with impaired infant mental development, and whether antioxidant/detoxification factors modulate this association.
  
  
  METHODS
  In the Spanish INfancia y Medio Ambiente (INMA; Environment and Childhood) Project, 2,644 pregnant women were recruited during their first trimester. Nitrogen dioxide (NO2) and benzene were measured with passive samplers covering the study areas. Land use regression models were developed for each pollutant to predict average outdoor air pollution levels for the entire pregnancy at each residential address. Maternal diet was obtained at first trimester through a validated food frequency questionnaire. Around 14 months, infant mental development was assessed using Bayley Scales of Infant Development.
  
  
  RESULTS
  Among the 1,889 children included in the analysis, mean exposure during pregnancy was 29.0 μg/m3 for NO2 and 1.5 μg/m3 for benzene. Exposure to NO2 and benzene showed an inverse association with mental development, although not statistically significant, after adjusting for potential confounders [β (95% confidence interval) = -0.95 (-3.90, 1.89) and -1.57 (-3.69, 0.56), respectively, for a doubling of each compound]. Stronger inverse associations were estimated for both pollutants among infants whose mothers reported low intakes of fruits/vegetables during pregnancy [-4.13 (-7.06, -1.21) and -4.37 (-6.89, -1.86) for NO2 and benzene, respectively], with little evidence of associations in the high-intake group (interaction p-values of 0.073 and 0.047). Inverse associations were also stronger in non-breast-fed infants and infants with low maternal vitamin D, but effect estimates and interactions were not significant.
  
  
  CONCLUSIONS
  Our findings suggest that prenatal exposure to residential air pollutants may adversely affect infant mental development, but potential effects may be limited to infants whose mothers report low antioxidant intakes.
authors.affiliation: Center for Research in Environmental Epidemiology, Carrer Dr. Aiguader 88, Barcelona, Catalonia, Spain. mguxens@creal.cat
authors.forename: Mònica
authors.initials: M
authors.lastname: Guxens
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Aguilera
authors.forename: Ferran
authors.initials: F
authors.lastname: Ballester
authors.forename: Marisa
authors.initials: M
authors.lastname: Estarlich
authors.forename: Ana
authors.initials: A
authors.lastname: Fernández-Somoano
authors.forename: Aitana
authors.initials: A
authors.lastname: Lertxundi
authors.forename: Nerea
authors.initials: N
authors.lastname: Lertxundi
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Mendez
authors.forename: Adonina
authors.initials: A
authors.lastname: Tardón
authors.forename: Martine
authors.initials: M
authors.lastname: Vrijheid
authors.forename: Jordi
authors.initials: J
authors.lastname: Sunyer
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D000975:Antioxidants / Q000494:pharmacology*; D002657:Child Development / Q000187:drug effects*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D018811:Maternal Exposure; D011247:Pregnancy; D039401:Prenatal Nutritional Physiological Phenomena
chemical_list: D000393:Air Pollutants; D000975:Antioxidants