Funds from this grant support a project by Jonathan Abbatt, professor of chemistry at the University of Toronto, to conduct preliminary research on the chemistry occurring on indoor surfaces. Indoor surfaces are covered by films of semi-volatile chemical species that arise through the deposition of particulates, oils, and gas-phase oxidation products. This layer is known as the semi-volatile surface layer (SVSL). Abbatt’s research will address three fundamental issues associated with indoor SVSLs. First, what is the chemical composition of indoor SVSL’s, and how is it influenced by deposition time and location? Second, how reactive are indoor SVSL’s as a function of environmental conditions, such as relative humidity? Third, what analytical techniques are well suited for the chemical study of indoor SVSLs?Abbat will conduct studies on both model and genuine surfaces using a variety of analytical techniques including infrared spectroscopy, nuclear magnetic resonance spectroscopy and Direct Analysis in Real Time–Mass Spectrometry (DART-MS), a new technology that has not yet been applied to the study of indoor chemistry.