The budgets of organic carbon composition and oxidation in indoor air

The chemical composition of indoor air at the University of Colorado-Boulder art museum was measured by a suite of gas- and particle-phase instruments. Over 80% of the total observed organic carbon (TOOC) mass (100 μg m-3) consisted of reduced compounds (carbon oxidation state, OSC 7) and low carbon number (nC < 6). The museum TOOC was compared to other indoor and outdoor locations, which increased according to the following trend: remote < rural ≤ urban < indoor ≤ megacity. The museum TOOC was comparable to a university classroom and 3x less than residential environments. Trends in total reactive flux were remote < indoor < rural < urban < megacity. High VOC concentrations compensated low oxidant concentrations indoors to result in an appreciable reactive flux. Total hydroxyl radical (OH), ozone (O3), nitrate radical (NO3), and chlorine atom (Cl) reactivities for each location followed a similar trend to TOOC. High human occupancy events increased all oxidant react...