Human occupants in the built environment, indoor air chemistry and ventilation strategies

Research Project, 2017 – 2019

Ozone transported from outdoors via ventilation reacts with squalene - a component and a natural antioxidant in our skin. Reaction products released to the air are highly oxygenated volatile organic compounds that have been proven irritating and sensitizing, and particles. Air exchange rate controls both amounts of ozone introduced from the outdoor air, reaction time available for the chemical processes and concentration levels of the products. Levels of the reaction products can be limited by well-designed ventilation. We will in this project study the formation and concentrations of these oxygenated reaction products both in bulk room air and in breathing zone of occupants, in real time using a high resolution mass spectrometer and particle counters. The first part will include controlled experiments in a climatic chamber to optimize ventilation and filtration scenarios designed to reduce the formation of the reaction products and development of a modelling tool. In a second phase, we will study typical concentrations of the oxygenated reaction products in environments with high occupant density - a school and an office building constructed as a passive house. Results from the project are anticipated to lead to increased understanding of indoor air chemistry. This, in turn, enables authorities to develop effective safeguards to limit the formation and health impacts of products from reactive ozone chemistry in indoor environments.