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

Abstract
Background 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.
Methods 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.
Results 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).
Conclusion 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.
Keywords Particulate matter, Green space, Developmental milestones, Neurodevelopment