Indoor air quality is vital to human health, as we spend most of our time indoors, particularly at home. Indoor activities, such as cooking or cleaning, may elevate indoor pollution levels, while outdoor pollution enters buildings through windows, doors, ventilation, or structural leaks. Pollutants generated indoors, such as volatile organic compounds or particulate matter, can also exit through these same pathways, contributing to poor urban air quality. Moreover, indoor chemistry differs from outdoor chemistry, adding complexity to how these pollutants transform during transport and produce secondary pollutants such as secondary organic aerosols and ozone, highlighting the interconnection between indoor and outdoor environments. Therefore, understanding this interface is essential for developing effective interventions and informing policy. It requires insights into indoor emission sources, chemical transformation, indoor-outdoor transport processes, and the influence of occupant behaviour.

This session invites contributions from laboratory experiments, field observations, and modelling studies that advance our knowledge of the indoor-outdoor air pollution interface. We particularly encourage submissions addressing indoor emission sources, pollutant dynamics, and exposure assessments.