Attaining neurodevelopmental milestones and exposures to fine particulate matter and environmental green spaces

Early-life environmental exposures may influence infant neurodevelopment. We examined associations between perinatal air pollution, green space exposure, and milestone attainment during the first two years. We conducted a longitudinal population study of Flemish children born in 2018, using well-baby clinic data (n = 46,584). Outcomes were delay of six milestones within predefined windows assessed using the Dutch version of the Denver Developmental Screener, and the exact age at two milestones. Municipality-level PM2.5, PM10, and green space were assigned. Associations per interquartile-range (IQR) increase were estimated using multivariable logistic and linear regression with multiple imputation. PM2.5 was positively associated with delaying the milestone ‘Points at 6 body parts of a doll’ (OR = 1.13, 95% CI:1.04;1.22). PM10 was positively associated with delaying the milestones ‘Says sentences of 2 words’ (OR = 1.07, 95%CI:1.00;1.13), ‘Points at 6 body parts of a doll’ (OR = 1.11, 95%CI:1.05;1.18), and ‘Pulls up to standing position’ (OR = 1.11, 95%CI:1.02;1.22). Low green was significantly associated with a reduced odds of delaying the milestones ‘Says 2 sound-words with comprehension’ (OR = 0.89, 95%CI:0.85;0.93) and ‘Pulls up to standing position’ (OR = 0.87, 95%CI:0.81;0.94), and negatively associated with walking age in months (B=-0.094, 95%CI:-0.129;-0.059). High green was negatively associated with delaying the milestones ‘Says sentences of 2 words’ (OR = 0.96, 95%CI:0.94;0.99) and ‘Points at 6 body parts of a doll’ (OR = 0.93, 95%CI:0.89;0.96). Total green was negatively associated with delaying the milestones ‘Says 2 sound-words with comprehension’ (OR = 0.94, 95%CI:0.88;0.99) and ‘Points at 6 body parts of a doll’ (OR = 0.95, 95%CI:0.91;0.99), and also with walking age (B=-0.054, 95%CI:-0.089;-0.019). PM exposure was linked to delays, while green space exposure showed a protective association. These findings support reducing PM10/PM2.5) and promoting green space exposures for child development.