Environment/Climate Change
Perinatal exposure to meteorological-air pollutant mixture and autism spectrum disorders Wanyu Huang* Wanyu Huang Huang Huang Huang Huang Huang Huang Huang Huang Huang Huang Huang Huang Huang Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, US
Objective: The prenatal period is critical for brain formation and neurodevelopment. Prenatal exposures to, for example, PM2.5 and extreme weather may increase the risk of neurodevelopmental disorders. Yet few studies have examined the joint effect of air pollutants and meteorological factors with autism spectrum disorder (ASD) in children.
Methods: Daily levels of temperature, relative humidity and fine particulate matter (PM2.5) from spatiotemporal models were linked to a longitudinal cohort of mothers/infants from the Medicaid Analytic eXtract (MAX) database. ASD was identified based on ICD-9/10 codes and modeled as a time-to-event outcome. Weekly levels of each exposure were assigned based on residential zip codes for mothers, then averaged into levels during each trimester. Quantile g-computation models were applied to assess the joint effects of the mixture, adjusting for maternal age, race/ethnicity, socioeconomic factors (area-level), as well as season of delivery.
Results: We included a total of 1,543,129 term births from 2001 to 2013; and observed a cumulative hazard ratio (HR) of 1.05 (95% CI: 0.95 – 1.15) for the mixture per interquartile range (IQR) increase in exposure. Of the factors that were associated with increased ASD, third-trimester PM2.5 contributed the largest share of the positive effect (42%), followed by first- and second trimester relative humidity. Some factors (e.g., 3rd trimester temperature) had an inverse association with ASD (Fig. 1).
Conclusion: PM2.5, especially during the third trimester, contributed the most to the increased risk of ASD, with relative humidity in the 1st and 2nd trimesters also contributing to the association. Continuing to mitigate ambient PM2.5 levels is important in potentially alleviating childhood ASD risk among the socioeconomically disadvantaged US population.
