Prenatal PM2.5 exposure and neurodevelopment at 2 years of age in a birth cohort from Mexico city.

Abstract Background Recent studies have reported that air pollution exposure may have neurotoxic properties. Objective To examine longitudinal associations between prenatal particles less than 2.5 μm in diameter (PM2.5) exposure and neurodevelopment during the first two years of children's life. Methods Analysis was conducted in PROGRESS, a longitudinal birth cohort between 2007 and 2013 in Mexico City. We used satellite data to predict daily PM2.5 concentrations at high spatial resolution. Multivariate mixed-effect regression models were adjusted to examine cognitive, language and motor scores in children up to 24 months of age (n = 740) and each trimester-specific and whole pregnancy exposure to PM2.5. Results: Models adjusted by child sex, gestational age, birth weight, smoking and mother's IQ, showed that each increase of 1 μg/m3 of PM2.5 was associated with a decreased language function of −0.38 points (95% CI: −0.77, −0.01). PM2.5 exposure at third trimester of pregnancy contributed most to the observed association. Conclusion Our findings suggest that language development up to 24 months of age may be particularly sensitive to PM2.5 exposure during pregnancy.