title: Association between prenatal exposure to traffic-related air pollution and preterm birth in the PELAGIE mother-child cohort, Brittany, France. Does the urban-rural context matter?
abstract: BACKGROUND
  Evidence has accumulated that exposure to ambient air pollution during pregnancy may influence preterm birth (PTB) in urban settings. Conversely, this relation has barely been investigated in rural areas where individual characteristics (demographic, socioeconomic, and psychosocial factors) and environmental co-exposures may differ.
  
  
  OBJECTIVE
  We examined the association between prenatal exposure to traffic-related air pollution and PTB among pregnant women from the PELAGIE mother-child cohort (Brittany, France, 2002-2006) living in urban (n=1550) and rural (n=959) settings.
  
  
  METHODS
  Women's residences were classified as either urban or rural according to the French census bureau rural-urban definitions. Nitrogen dioxide (NO2) concentrations at home addresses were estimated from adjusted land-use regression models as a marker of traffic-related pollution. Associations between NO2 concentrations and PTB were assessed with logistic regression models.
  
  
  RESULTS
  Prevalence of PTB was similar among women living in urban (3.2%) and in rural (3.5%) settings. More positive socioeconomic characteristics and health behaviors but more single-parent families were observed among urban women. NO2 exposure averaged 20.8±6.6 µg m(-3) for women residing in urban areas and 18.8±5.6 µg m(-3) for their rural counterparts. A statistically significant increased risk of PTB was observed among women exposed to NO2 concentrations ≥16.4 µg m(-3) and residing in urban areas but not among their rural counterparts.
  
  
  CONCLUSIONS
  The results of this study, conducted in a region with interspersed urban-rural areas, are in line with previous findings suggesting an increased risk of PTB associated with higher NO2 concentrations for women living in urban areas. The absence of association among their rural counterparts for whom exposure levels were similar suggests that environmental mixtures and psychosocial inequalities might play a role in this heterogeneity.
authors.affiliation: INSERM U1085-IRSET, avenue Professeur Léon Bernard, 35043 Rennes, France; University of Rennes 1, Rennes, France; EHESP School of Public Health, Sorbonne Paris Cité, Rennes, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Bertin
authors.affiliation: INSERM U1085-IRSET, avenue Professeur Léon Bernard, 35043 Rennes, France; University of Rennes 1, Rennes, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Chevrier
authors.affiliation: INSERM U1085-IRSET, avenue Professeur Léon Bernard, 35043 Rennes, France; University of Rennes 1, Rennes, France; EHESP School of Public Health, Sorbonne Paris Cité, Rennes, France.
authors.forename: Tania
authors.initials: T
authors.lastname: Serrano
authors.affiliation: INSERM U1085-IRSET, avenue Professeur Léon Bernard, 35043 Rennes, France; University of Rennes 1, Rennes, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Monfort
authors.affiliation: INSERM U1085-IRSET, avenue Professeur Léon Bernard, 35043 Rennes, France; University of Rennes 1, Rennes, France; Department of Pediatrics, University Hospital, Rennes, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Rouget
authors.affiliation: INSERM U1085-IRSET, avenue Professeur Léon Bernard, 35043 Rennes, France; University of Rennes 1, Rennes, France.
authors.forename: Sylvaine
authors.initials: S
authors.lastname: Cordier
authors.affiliation: INSERM U1085-IRSET, avenue Professeur Léon Bernard, 35043 Rennes, France; University of Rennes 1, Rennes, France; Department of Epidemiology and Public Health, University Hospital, Rennes, France. Electronic address: jean-francois.viel@univ-rennes1.fr.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Viel
mesh_terms: D000397:Air Pollution / Q000009:adverse effects / Q000032:analysis*; D015331:Cohort Studies; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D007231:Infant, Newborn; D016015:Logistic Models; D018811:Maternal Exposure / Q000009:adverse effects / Q000706:statistics & numerical data; D009585:Nitrogen Dioxide / Q000032:analysis* / Q000633:toxicity; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology / Q000209:etiology*; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced* / Q000453:epidemiology; D015995:Prevalence; D012424:Rural Population / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D014505:Urban Population / Q000706:statistics & numerical data; D001335:Vehicle Emissions / Q000032:analysis* / Q000633:toxicity
chemical_list: D001335:Vehicle Emissions; D009585:Nitrogen Dioxide
keywords: Nitrogen dioxide; Preterm birth; Traffic-related air pollution; Urban–rural context