Funds from this grant support a project by Tara S. Kahan, Associate Professor of Chemistry at the University of Saskatchewan, in collaboration with Jianshun Zhang, Professor of Mechanical Engineering, at Syracuse University to examine indoor photon fluxes and determine concentrations, sources, and sinks of indoor oxidants and oxidant precursors. The project will combine laboratory, field, and chamber studies to better understand oxidizing capacity from emerging precursors in residences. Kahan will investigate the sources and sinks of indoor oxidants by measuring oxidant precursor concentrations in three residences, measuring indoor photon fluxes under a range of conditions, and determining oxidant concentrations via chamber experiments that simulate indoor conditions. The results will be shared through peer-reviewed publications in journals such as Environmental Sciences & Technology and Indoor Air. The team also plans to make presentations at conferences and meetings, including meetings of the International Society of Indoor Air Quality and Climate and the American Association for Aerosol Research. One postdoctoral scholar, three graduate students, and one undergraduate student will be trained on this project.