Modeling is essential to the development of indoor chemistry as a field. Comprehensive, integrated physical-chemical models that include a realistic representation of how buildings influence indoor processes are needed to assess gaps in our understanding, to improve experimental design, to generate hypotheses for investigation, to guide measurements, and to indicate key species to quantify and the detection limits required for quantification. The MOdelling Consortium for Chemistry of Indoor Environments (MOCCIE) consists of six teams of investigators with expertise and models in six different areas: kinetic process modeling, gas-phase chemistry modeling, molecular dynamics simulations, modeling of indoor secondary organic aerosols and organic aerosols, computational fluid dynamics modeling, and modeling surface interactions and the role of clothing and textiles. MOCCIE has determined that the best way to ensure reproducible indoor chemical science would be to strive to construct a fully integrated open source model. This requires converting each of the six existing MOCCIE models into an open source format. Funds from this grant would support a project to convert Nicola Carslaw’s gas phase chemistry model into a fully open source platform using the Python programming language. Additional funds support the construction of a new user-friendly interface to facilitate the model’s use and production of supporting documentation.   In addition to the modeling work, Carslaw will work to expand science communications about indoor chemistry by engaging a U.K.-based freelance science journalist, Nina Notman. Notman will attend indoor chemistry events and conferences, and give a plenary on science communication at the 2018 Indoor Air Conference.

This grant funds a project led by Assistant Professor Marina Vance of the University of Colorado, Boulder, in collaboration with Associate Professor Delphine Farmer of Colorado State University to initiate the development of a data infrastructure for the field of indoor chemistry through an interdisciplinary collaborative field experiment named “House Observations of Microbial and Environmental Chemistry” (HOMEChem). The HOMEChem experiment will take place at a test house at the University of Texas at Austin in the summer of 2018, where researchers from 9 universities will aim to identify the most important factors controlling chemistry in indoor environments. Teams from each of these nine universities will make a wide range of measurements of the test house, including building and ventilation metrics; environmental parameters; spectral radiance and photolysis rates; aerosol concentrations and size distributions; aerosol composition; and the presence or absence of elemental and oxidized carbon, gas and particle phase organics, nitrogen oxides, ozone, nitrous acid, carbon monoxide, carbon dioxide, and methane. Many of these factors will be the subject of multiple measurements by more than one instrument, allowing comparison of instruments and collection methodologies. In addition, Vance and Farmer will conduct controlled experiments regarding cooking and cleaning, so see how these common household activities affect the chemistry that takes place inside the house. The HOMEChem experiment promises not only to result in new knowledge about indoor chemistry, but to surface important issues regarding shared data and metadata needs among indoor chemists and to build community as the various research teams work together to execute the experiment and interpret their joint findings. Research results will be shared through at least eight publications and twenty presentations at high-profile sessions and plenaries at national and international meetings.

Funds from this grant support efforts by Manabu Shiraiwa, assistant professor of chemistry at the University of California, Irvine, in collaboration with Nicola Carslaw at the University of York, to develop and lead an indoor chemistry modeling consortium. This two-year project will bring together experts from several different fields to begin to develop a model that realistically represents how buildings influence indoor chemical processes. The team will begin to find ways to link six different modeling techniques that deal with different aspects of indoor chemistry on scales ranging from micro- to macroscale and from very short (less than 1 second) to much longer lifetimes. The modeling consortium plans to address the following research questions: (1) Can we understand indoor chemistry well enough to predict it quantitatively with computer models of chemical and physical processes? (2) What are the major uncertainties that currently exist in these models? (3) What experiments/field measurements do we need to improve our models? (4) What experiments/field measurements do we need to evaluate our models? Models will be developed within the framework of exploring two relevant and highly topical research themes for indoor air chemistry: (1) reactions between indoor oxidants and human skin and (2) cleaning-related emissions of volatile organic compounds (VOCs). The research team will also conduct three workshops—at the beginning, middle, and end of the project—to foster collaboration and communication as well as to provide in-person opportunities to review work plans and progress. Six early-career researchers will be trained. The new knowledge and modeling tools will be shared in peer-reviewed publications as well as through presentations at conferences, such as Indoor Air 2018 and the American Association for Aerosol Research (AAAR) meeting.

This grant, to Barbara Turpin, professor and chair of the Department of Environmental Sciences and Engineering at the University of North Carolina, Chapel Hill, will fund three-year effort to examine the roles of dampness, water-soluble organic gases (WSOGs), and surface chemistry on indoor air composition. The project is designed to improve characterization of indoor WSOGs, their chemistry and fate indoors, and to provide key information needed to predict the degree to which water in damp homes may alter indoor air composition. The research will address the following questions by conducting controlled experiments with real indoor surfaces at high vs. low relative humidity: What is the uptake rate and equilibrium partitioning of WSOGs on typical indoor surfaces? How much liquid water absorbs on these surfaces and how does liquid water mediate uptake? The research will also provide insights into surface chemistry and product formation in damp homes by measuring real-time chemical changes on indoor surfaces after the introduction of key gases (ozone, water vapor, and WSOGs) using sophisticated state-of-the-art spectroscopic techniques. Finally, the UNC team will pilot real-time molecular-level characterization of WSOGs in one to three homes using high-resolution time-of-flight chemical ionization mass spectrometry (HR-ToF-CIMS) over 15 days. The project will create new knowledge about the roles of dampness, water-soluble organic gases, and surface chemistry on indoor air composition. The research findings will be shared through peer-reviewed publications and presentations at national and international conferences.

This grant funds a research project by atmospheric photochemist D. James Donaldson, professor at the University of Toronto, and Christian George, a senior scientist at France’s National Center for Scientific Research (CNRS) in Lyon, France to investigate the role of photochemistry indoors. The team plans to establish whether heterogeneous (gas/surface) photochemical reactions occur indoors, producing gas phase oxidants and their precursors, as well as particles. The team plans to address three main questions: (1) Are indoor surfaces of occupied spaces photochemically active in the formation of gas phase oxidants? (2) If so, how do local variables (temperature, relative humidity, specifics of illumination) affect the formation of gas phase oxidants? (3) Is heterogeneous photochemistry a source of indoor particulate matter? These questions will be addressed through a series of laboratory and chamber experiments in both laboratories in Toronto, Canada, and Lyon, France. To facilitate the long-distance collaboration, the team will conduct a series of two-way student exchanges, as well as annual meetings between the principal investigators in Toronto and Lyon. This exchange of students will encourage and support strong international scientific ties at all levels, allowing students to experience different societies and laboratory structures, and better preparing them for transnational activities in the future. This project promises to provide new knowledge about indoor photochemistry. The results will be shared through peer-reviewed publications and presentations at conferences and meetings. At least three undergraduate students, three graduate students, and two postdoctoral fellows will be trained.