Air pollution is the main urban-related environmental hazard. It appears to affect brain development, although current evidence is inadequate given the lack of studies during the most vulnerable stages of brain development and the lack of brain anatomical structure and regional connectivity data underlying these effects. Of particular interest is the prenatal period, when brain structures are forming and growing, and when the effect of in utero exposure to environmental factors may cause permanent brain injury.
AIR-NB aimed to provide a robust and comprehensive evaluation of the impact of maternal exposure to urbain air pollutants on fetal and neonatal brain development.
Towards this aim it establishes a new pregnancy cohort of 1,080 pregrant women and 1,032 neonates in Barcelona (BISC: Barcelona Life Study Cohort), Spain. Brain development was characterized by brain ultrasound at gestional week of 32, brain MRI at 28 days of life, Bayley cognitive test at 18 months of age, and attentional eye-tracking experiments at 6 and 18 months of age. We developped an innovative exposure assessment framework integrating objective data on time-activity patterns with dispersion, land use regression, and hybrid models and campaigns of personnel and home outdoor air pollution monitoring to estimate maternal exposure level as well as inhaled dose of black carbon (BC), NO2, PM2.5 elemental content, in the main microenvironments for pregnant women (home, workplace, and commuting routes). We also assessed maternal exposure to noise by integrating measurements at participants' home-outdoor using noise monitors with modelled microenvironmental levels of noise. We also assessed greenspace exposure using high-resolution maps. We evaluated the modification of associations by SES, stress (cortisol levels and perceived stress), physical activity (objective and subjective measures), maternal cognition and mental health, their mitigation by urban greenness and canopy volume, and their mediation by ultrasound measures of placental hemodynamic function. Black carbon particles were detected in placenta and cord blood.
Preliminary analyses demonstrate: urban air pollution is associate with impaired pre-natal and early-life brain development. These results will create an impulse to implement policy interventions that genuinely protect the health of urban citizens.
