Residential Outdoor Air Pollution and Brain Morphology in the Adult Health and Behavior (AHAB Ⅱ) Cohort and Pittsburgh

摘要

Background: Air pollution exposure is associated with increased inflammatory risk, and may adversely impact brain morphology through systemic inflammation, disruption of the blood-brain barrier, or translocation via olfactory mucosa. Currently, little is known about the relationship between air pollutants (particulate matter (PM_(2.5)), black carbon (BC), trace metal constituents) and brain morphology. The AHAB-Ⅱ cohort is a community-based registry to identify neural and biobehavioral predictors of physical and mental health in midlife. We combine individual brain morphology indicators with fine-scale air pollution exposure estimates to explore their associations. Aims: Geographic information system (GIS) was used to geocode participant addresses and assign individual air pollution exposure estimates. We developed models to examine associations between outdoor air pollution and brain morphology. Methods: Air pollution data were obtained from a monitoring campaign with 36 sites across the Pittsburgh region. Land use regression (LUR) models were developed for PM2.5, BC, and lead. We assigned mean pollutant concentrations within a 300 m buffer of each participant's residential location (n=306; mean age = 43 yrs; 45% men). Structural neuroimaging methods were used to determine indicators of brain morphology. Results: Preliminary results suggest that a 1 μg/m3 increase in summer PM_(2.5) exposure is associated with a -0.019 mm (p ≤ .05) decrease in cortical thickness after controlling for intracranial volume and age. Future analyses will examine other outcomes, and potentially mediating factors related to inflammation. Conclusions: This is among the first studies to examine associations between residence-specific air pollution exposures and brain morphology. Observed associations may have implications for pollution effects on brain-based functional outcomes (e.g., early cognitive declines).