Effects of prenatal exposure to PM 2.5 and its composition on cognitive and motor functions in children at 12 months of age: The Shanghai Birth Cohort Study.

Background: Prenatal fine particulate matter (PM _2.5 ) exposure has been linked to infant cognitive and motor functions, but the effects of PM _2.5 chemical composition remain unclear.
Objectives: We aimed to explore the associations of prenatal PM _2.5 and its composition exposure with infant cognitive and motor functions.
Methods: We studied 2,435 mother-infant pairs in the Shanghai Birth Cohort Study. PM _2.5 and its seven compositions [primary particles (black carbon, mineral dust and sea salts) and secondary particles (NH ₄ ⁺ , NO ₃ ^- , SO ₄ ^2- and organic matter)] during thethreetrimesters ofpregnancy were retrieved from the V4.CH.03 product developed by using a combined geoscience-statistical method. At the 12-month-old follow-up, infant cognitive and motor functions in five domains were assessed using the Ages and Stages Questionnaire (ASQ). We used multivariable linear regressions to estimate the effects of PM _2.5 and its composition on the ASQ scores, for all infants and stratifying by sex and breastfeeding duration.
Results: PM _2.5 exposure was negatively associated with gross motor, problem-solving and personal-social scores for all infants. PM _2.5 compositions were inversely associated with ASQ scores in all five domains, and the effects of different compositions varied across domains. Specifically, all compositions except organic matter were correlated with lower problem-solving scores [e.g., ( [Formula: see text]  =  - 10.79, 95 % CI: -17.40, -4.18) ∼ ( [Formula: see text]  =  - 4.68, 95 % CI: -7.84, -1.53); for each 10 μg/m ³ increase in PM _2.5 compositions during the third trimester]. Primary and some secondary particles (organic matter, NO ₃ ^- ) were related to lower gross motor scores. Secondary particles were also inversely associated with communication (organic matter and NO ₃ ^- ), fine motor (NH ₄ ⁺ , NO ₃ ^- , SO ₄ ^2- ) and personal-social (NH ₄ ⁺ ) scores. Additionally, boys and infants breastfed for < 6 months appeared to be more susceptible.
Conclusions: We found negative associations of PM _2.5 and its compositions with infant cognitive and motor functions over a range of domains, especially the problem-solving domain.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022. Published by Elsevier Ltd.)