title: Prenatal and childhood traffic-related air pollution exposure and childhood executive function and behavior.
abstract: Traffic-related air pollution exposure may influence brain development and function and thus be related to neurobehavioral problems in children, but little is known about windows of susceptibility.
  
  
  
  Examine associations of gestational and childhood exposure to traffic-related pollution with executive function and behavior problems in children.
  
  
  
  We studied associations of pre- and postnatal pollution exposures with neurobehavioral outcomes in 1212 children in the Project Viva pre-birth cohort followed to mid-childhood (median age 7.7years). Parents and classroom teachers completed the Behavior Rating Inventory of Executive Function (BRIEF) and the Strengths and Difficulties Questionnaire (SDQ). Using validated spatiotemporal models, we estimated exposure to black carbon (BC) and fine particulate matter (PM2.5) in the third trimester of pregnancy, from birth to 3years, from birth to 6years, and in the year before behavioral ratings. We also measured residential distance to major roadways and near-residence traffic density at birth and in mid-childhood. We estimated associations of BC, PM2.5, and other traffic exposure measures with BRIEF and SDQ scores, adjusted for potential confounders.
  
  
  
  Higher childhood BC exposure was associated with higher teacher-rated BRIEF Behavioral Regulation Index (BRI) scores, indicating greater problems: 1.0 points (95% confidence interval (CI): 0.0, 2.1) per interquartile range (IQR) increase in birth-age 6BC, and 1.7 points (95% CI: 0.6, 2.8) for BC in the year prior to behavioral ratings. Mid-childhood residential traffic density was also associated with BRI score (0.6, 95% CI: 0.1, 1.1). Birth-age 3BC was not associated with BRIEF or SDQ scores. Third trimester BC exposure was not associated with teacher-rated BRI scores (-0.2, 95% CI: -1.1, 0.8), and predicted lower scores (fewer problems) on the BRIEF Metacognition Index (-1.2, 95% CI: -2.2, -0.2) and SDQ total difficulties (-0.9, 95% CI: -1.4, -0.4). PM2.5exposure was associated with teacher-rated BRIEF and SDQ scores in minimally adjusted models but associations attenuated with covariate adjustment. None of the parent-rated outcomes suggested adverse effects of greater pollution exposure at any time point.
  
  
  
  Children with higher mid-childhood exposure to BC and greater near-residence traffic density in mid-childhood had greater problems with behavioral regulation as assessed by classroom teachers, but not as assessed by parents. Prenatal and early childhood exposure to traffic-related pollution did not predict greater executive function or behavior problems; third trimester BC was associated with lower scores (representing fewer problems) on measures of metacognition and behavioral problems.
authors.affiliation: Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA. Electronic address: mariaharris@berkeley.edu.
authors.forename: Maria H
authors.initials: MH
authors.lastname: Harris
authors.affiliation: Channing Laboratory, Brigham and Women's Hospital, Boston, MA, USA; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Diane R
authors.initials: DR
authors.lastname: Gold
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA.
authors.forename: Sheryl L
authors.initials: SL
authors.lastname: Rifas-Shiman
authors.affiliation: Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Melly
authors.affiliation: Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Antonella
authors.initials: A
authors.lastname: Zanobetti
authors.affiliation: Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Brent A
authors.initials: BA
authors.lastname: Coull
authors.affiliation: Channing Laboratory, Brigham and Women's Hospital, Boston, MA, USA; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Schwartz
authors.affiliation: Department of Hygiene, Epidemiology and Medical Statistics, University of Athens Medical School, Athens, Greece.
authors.forename: Alexandros
authors.initials: A
authors.lastname: Gryparis
authors.affiliation: Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA; The Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Itai
authors.initials: I
authors.lastname: Kloog
authors.affiliation: Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Petros
authors.initials: P
authors.lastname: Koutrakis
authors.affiliation: Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Bellinger
authors.affiliation: Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Mandy B
authors.initials: MB
authors.lastname: Belfort
authors.affiliation: Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Webster
authors.affiliation: Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA.
authors.forename: Roberta F
authors.initials: RF
authors.lastname: White
authors.affiliation: Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA; Center for Environmental Research and Children's Health, School of Public Health, University of California at Berkeley, Berkeley, CA, USA.
authors.forename: Sharon K
authors.initials: SK
authors.lastname: Sagiv
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Oken
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000009:adverse effects*; D056344:Executive Function; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000523:psychology*; D000066553:Problem Behavior; D001335:Vehicle Emissions / Q000633:toxicity
chemical_list: D000393:Air Pollutants; D001335:Vehicle Emissions
keywords: Air pollution; Black carbon; Executive function; Neurodevelopment; Traffic