Recent advances in instrumentation have transformed our ability to study chemical reactions and analyze the composition of chemicals in the air. These advances provide an excellent opportunity to expand our understanding of the chemistry of indoor environments. This grant funds a preliminary study by Barbara J. Turpin, a professor in the Department of Environmental Sciences and Engineering at the University of North Carolina, Chapel Hill, of the impact of moisture on indoor chemistry. Turpin and her team plan to take samples from the air of 10 to 20 occupied homes, treat the samples with indoor oxidants (reactants) such as OH or NO3 radicals, and then monitor the reaction products using a variety of techniques. The study builds on Turpin’s prior work demonstrating that aqueous organic chemistry alters the composition and effects of air pollution outdoors. Turpin expects to produce at least two peer-reviewed articles based on the study, and she and her team will present their findings at national and international meetings. In addition, Turpin will prepare a short report that outlines important research questions and obstacles to be overcome for indoor air chemistry.