Dissertation Defense: Selene Tang

"Multiscale Exposome Analysis of SVOCs/PFAS Mixtures: From Personal Asthma Exposure to Community-Level Environmental Pathways", School of Public Health Department of Environmental and Occupational Health. Committee: Sally E. Wenzel, (committee chair) EOHPeng Gao, Harvard T.H. Chan School of Public HealthCarla A. Ng, EOH, Swanson School of EngineeringFranziska J. Rosser, UPMC Children's Hospital of PittsburghTravis L. Knuckles, EOHAbstract: Multiscale Exposome Analysis of SVOCs/PFAS Mixtures: From Personal Asthma Exposure to Community-Level Environmental Pathways Environmental exposures to complex chemical mixtures are difficult to characterize using conventional monitoring approaches, particularly when exposures vary across individuals, environmental matrices, and spatial scales. This dissertation applies exposome-informed methods to characterize semi-volatile organic compounds (SVOCs) and per- and polyfluoroalkyl substances (PFAS) across two complementary settings: personal airborne exposure among adults with asthma and community-level environmental contamination following a train derailment. Aim 1 evaluated silicone wristbands as personal passive samplers for airborne exposome profiling in 40 adults with physician-diagnosed asthma in Pittsburgh, Pennsylvania. Participants wore wristbands for one week, and 114 airborne chemicals, including phthalates, polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers, and PFAS, were quantified using GC–MS and UHPLC–MS/MS. Asthma severity/control and airway obstruction were classified using medication use, Asthma Control Test scores, and pre-bronchodilator FEV1% predicted. In exploratory analyses not corrected for multiple testing, severe airway obstruction was associated with nominally higher butyl benzyl phthalate and PCB-132, while non-severe controlled asthma participants showed nominally higher diamyl phthalate, PCB-33, PCB-87, and PCB-209 than severe uncontrolled asthma.