A new framework for indoor air chemistry measurements: Towards a better understanding of indoor air pollution

This paper reports on the findings from INDAIRPOLLNET (INDoor AIR POLLution NETwork), a recently completed European COST Action network. INDAIRPOLLNET ran from September 2018 to March 2023 with more than 200 indoor and outdoor air quality scientists from universities, large and small companies, and research institutes around Europe and beyond. The expertise of our interdisciplinary network members covered chemistry, biology, standardisation, household energy, particulate matter characterisation, toxicology, exposure assessment, air cleaning, building materials, building physics and engineering (including ventilation and energy), and building design. The aim of INDAIRPOLLNET was to design a framework for future indoor air chemistry field campaigns, building on our improved understanding of indoor air chemistry. The main focus of our network was to better understand the sources, transformations and fate of chemical pollutants found in the air in buildings. In this paper, we present the main findings from our network, which include a call for greater spatial and temporal coverage of measurements indoors, the need for standardised techniques for indoor measurements and the impact of occupants on indoor air quality. We also present a checklist of building parameters that should be measured in any future indoor air campaign. Finally, we present our new framework, focusing on 5 key research areas: reactivity in indoor environments; mapping organic constituents indoors; the role of the occupant in indoor air chemistry; indoor modelling studies and novel materials and technologies indoors. We hope this framework will be of use to the indoor air quality community, enabling healthier buildings for the future.