Nearly one in five Americans spends time in school buildings each school day. Despite troubling findings that poor indoor air quality can reduce cognitive performance in students, schools are often not well maintained. There are nearly 600,000 portable classrooms, also known as trailers, across the country and, unfortunately, these spaces are plagued with poor ventilation, water intrusion, and high levels of formaldehyde. Funds from this grant support a project by Professor of Engineering Kerry Kinney and colleagues Richard Corsi, Atila Novoselac, and Ying Xu at the University of Texas at Austin to determine how the microbiome and air quality inside portable classroom buildings are affected by ventilation conditions and building design. The proposed project will examine the relationship between the microorganisms and pollutants found inside the actual classroom spaces to those found in the “hidden spaces” (e.g., wall cavities, crawl spaces) within portable classroom buildings, aiming to identify where microbes and other contaminants come from and where they go within the actual classroom and hidden spaces. The research team will also investigate how positive and negative pressurization from the ventilation systems affects the microbiota and other contaminants in various parts of the portable classroom.