About the Seminar:

Humans spend most of their time indoors, yet little consideration is made about indoor health exposures. Previous studies focused on gas phase contaminants, but surfaces like drywall, carpet, glass, etc. play a unique role since different reactions occur on surfaces versus the gas phase, which lead to new contaminants. Surfaces also act as a major source for known indoor gas phase compounds. Little is known about how different surfaces contribute as a source and the location of these compounds in surface reservoirs. Studies show surfaces behave differently, and models show that diffusion likely occurs into the bulk for many gas-surface interactions. However, no direct measurements have been made. Using stable isotopes as a tracer, I can obtain direct measurements of gas-phase compounds for different surfaces and the inner bulk material. Several ecological studies have established the use of stable isotopes since the 1990s to understand complex systems. This would be the first time applying these stable isotope methods to an indoor environment. An Isotope Ratio Mass Spectrometer (IRMS) can quantify the amount of the isotope tracer in each surface and bulk layer measured. The Direct Analysis in Real Time Mass Spectrometer (DART-MS), which has been established for indoor glass surfaces, will supplement the IRMS by giving qualitative data on the oxidation products of each surface. By using both instruments, I will have direct measurements of where gases interact on surfaces and the products created. These measurements will help understand and model the role surfaces have indoors.