Title: Air Pollution Exposure Across Microenvironments and Associated Metabolic Pathways in Children Aged 3–4 Years

Abstract: Children are among the most vulnerable groups to the adverse health effects of air pollution due to their high breathing rates, developing immune systems, and time spent outdoors and in multiple microenvironments. Several studies have shown that exposure to air pollution in early life plays a vital role in triggering adverse health outcomes in adulthood, such as respiratory and cardiovascular disease. Currently, only a few studies have focused on children's exposure to air pollution and related health outcomes, especially among toddlers, due to challenges in conducting research with young children, including compliance with protocols and retention rates. This dissertation was designed to fill critical data gaps regarding early-life exposure by assessing indoor, outdoor, and personal air pollution (such as particulate matter, PM2.5, black carbon, BC, ozone, O3, nitrogen dioxide NO2 and trace metals, copper Cu, zinc Zn, lead Pb, cadmium Cd, chromium Cr, nickel Ni, etc.) levels among children aged 3–4 years in Atlanta, Georgia. This dissertation integrates exposure assessment, correction of low-cost PM sensors, and metabolomics to examine short-term air pollution exposure and its metabolic impacts. We collected indoor, outdoor, and personal exposure data across seven sampling campaigns at three daycare centers: high-traffic (S2), intermediate (S3), and background (S1). Saliva samples were analyzed using LC-MS-based metabolomics, and mixed-effects models were applied to investigate associations between pollutant exposure and metabolic pathways related to oxidative stress, lipid metabolism, and inflammation, while adjusting for sex, race, temperature, season, and baseline of metabolites. The results will improve understanding of mechanistic pathways linking short-term exposure to metabolic perturbations, guiding interventions to protect children's health.

Chair: Dr. Roby Greenwald