Environment/Climate Change
Prenatal exposure to wildfire smoke and risk of ASD/ADHD in children among Medicaid recipients: a national cohort study Stefania Papatheodorou* Stefania Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Papatheodorou Rutgers School of Public Health
Objective: Wildfires are an increasing threat to human health. While wildfire-attributed PM2.5 exposure has been linked to adverse birth outcomes, its potential impact on children’s neurodevelopment remains poorly characterized. We examined associations between prenatal wildfire PM2.5 exposure and risk of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in a large, national cohort of Medicaid-enrolled children.
Methods: We constructed a longitudinal mother–child cohort using the Medicaid Analytic eXtract (MAX) from 2007–2014. Prenatal wildfire PM2.5 exposure was assigned as pregnancy-average concentrations at the maternal residential ZIP code using daily spatiotemporal wildfire smoke models. ASD and ADHD were identified using ICD-9 codes. Cox hazards models stratified by year and county, coupled with distributed lag models, were used to estimate associations, adjusting for ambient temperature, relative humidity, maternal age, race/ethnicity, behavioral risk factors (smoking, alcohol, drug use), area-level socioeconomic status, and season of conception. Effect modification by child sex was assessed.
Results: The analysis included 1,010,197 births. A 1-µg/m³ increase in average prenatal wildfire PM2.5 exposure was associated with increased risk of ASD (overall HR = 1.07; 95% CI: 1.01–1.15) and ADHD (overall HR = 1.13; 95% CI: 1.09–1.17). We observed windows of increased susceptibility in mid-pregnancy. Associations were observed in both sexes but were stronger among females (ASD HR = 1.12; 95% CI: 1.03–1.26; ADHD HR = 1.18; 95% CI: 1.13–1.23) than males (ASD HR = 1.01; 95% CI: 1.00–1.08; ADHD HR = 1.11; 95% CI: 1.07–1.15).
Conclusions: Prenatal exposure to wildfire smoke was associated with increased risk of ASD and ADHD among children in a low-income U.S. population. These findings underscore the neurodevelopmental risks of wildfire-related air pollution and highlight the need for targeted public health interventions to protect pregnant individuals and children. Further research is warranted to clarify underlying biological mechanisms, sex-specific susceptibility, and sensitive exposure windows.