Abstract Body: Hypothesis: Adolescents aged 10 to 14 years exposed to higher levels of air pollution from fine particulates exhibit decreased brain volume, a negative impact that is mediated by high blood pressure.

Methods: Statistical analysis was conducted using data from the Adolescent Brain Cognitive Development study from 21 research sites across the United States. Of the participants included in the study, 3,990 participants aged 10 to 14 years old were identified for this investigation. Brain volume was measured using structural magnetic resonance imaging, high spatial and temporal resolution resting state scan and 3D T1-weighted magnetization-prepared rapid acquisition echo scans. The environmental exposure of air pollution (PM_2.5) was measured using geospatial data linking participants’ primary residential addresses with air pollution levels. Blood pressure, as potential mediators, was measured as a physical health parameters at baseline. Using the statistical software ‘STATA,’ regression models estimated the associations between air pollution and brain volume. Structural equation modeling demonstrated and estimated the mediating relationship between blood pressure, exposure, and outcome.

Results: The regression model estimated a negative correlation between air pollution (PM_2.5) and brain volume (. The structural equation modeling analysis for air pollution’s (PM_2.5) effect on brain volume mediated by blood pressure estimates the direct effect of air pollution (PM_2.5) on brain volume and the effect of blood pressure on brain volume in this model provides ; both effects were found to be statistically significant. The direct effect of air pollution (PM_2.5) on blood pressure is very small and not statistically significant. The total effect of air pollution (PM_2.5) on brain volume is
-28.88, a value that is very significant.
Conclusion: Exposure to higher amounts of fine particulates from air pollution (PM_2.5) was associated with decreased brain volume in young adolescents, and hypertension greatly mediated this relationship. The results of this investigation indicate elevated blood pressure may enhance a vulnerable population’s susceptibility, such as U.S. adolescents, to air pollution, that may lead to long-term diseases.