Prenatal exposure to traffic-related pollution and childhood cognition

摘要

Background: The prenatal period is a critical window for neurodevelopment. Recent research suggests that prenatal exposure to traffic-related pollution may negatively impact the developing brain, impairing childhood cognition. Aims: Examine prenatal exposure to traffic and related pollutants and performance on neurodevelopment tests among 1146 children in the Project Viva prospective pre-birth cohort. Methods: We assessed residential proximity to major roadways (class A1 or A2, e.g. state or interstate highways) at study enrollment (median 10.0 weeks gestation). We also estimated residential exposure to black carbon (BC) during the third trimester using a temporally- and spatially- resolved model. At mean age 8.0 (range 6.6-10.9) years, we measured children's verbal and non-verbal intelligence using the Kaufman Brief Intelligence Test and executive function using the Behavior Rating Inventory of Executive Function (teacher reported). We used linear regression to examine associations of categorical ranges of road proximity and quintiles of BC exposure with continuous test scores, adjusted for characteristics of the child (age and sex), mother (race/ethnicity, prenatal smoking, education, and IQ), household (income and HOME score) and neighborhood (% below poverty). BC models were also adjusted for year and season of birth. Results: In multivariate models, compared with those ＞50m from a major roadway, children whose mothers lived within 50m of a major roadway in pregnancy (n=41) had lower verbal IQ (-3.8 points, 95% confidence interval (CI): -8.1, 0.4), non-verbal IQ (-5.6 points, 95% CI: -11.1, -0.2), and somewhat poorer executive function (2.9 points, 95% CI: -1.1, 7.0). We observed no consistent patterns in outcomes across quintiles of third trimester BC exposure. Conclusions: Residential proximity to major roadways during gestation was associated with lower IQ at school age, but modeled third trimester BC exposure did not predict lower cognitive.