Toward a better understanding of indoor air quality holistically integrating improved and new instrumental analytical techniques

People in developed countries are estimated to spend 80–90% of their time indoors, where they can be exposed to poor air quality from numerous and diverse sources. These include mold growth and other microbial pollutants in humid air, to the chemical pollutants that result from emissions from human activities such as cooking, cleaning, smoking and home refurbishments. In fact, the concentrations of many air pollutants can be higher indoors than out, particularly following activities such as cleaning and cooking. Despite these facts, regulation for air pollution focuses mainly on outdoors and the indoor environment is much less well characterized or indeed regulated. With increasing climate change impacts expected in the future, related energy efficiency measures are making buildings considerably more airtight leading to the potential for even higher indoor air pollutant concentrations. Therefore, to reduce our exposure to air pollution, we must consider air pollutant sources and sinks in both the indoor and outdoor environments. We also need to consider the role of ventilation in mixing air between the two, in order to mitigate through appropriate building operation, use and design. Cost Action 17136 INDAIRPOLLNET (INDoor AIR POLLution NETwork) aims to improve our understanding of the cause of high concentrations of indoor air pollutants. It assembles experts in chemistry, biology, standardization, particulate matter characterization, toxicology, exposure assessment, building materials (including green materials), building physics and engineering and building design, performing laboratory and chamber experiments, modeling studies and measurements of relevance to indoor air quality, including outdoor air chemists. This Action is significantly advancing the field of indoor air pollution science, and highlighting future research areas, as well as aiming to to bridge the gap between research and business. In this way, we will be able to identify appropriate mitigation strategies that optimize indoor air quality. One of the objectives of our Action has been to explore the best ways to measure key indoor air pollutants given specific requirements (research question, available funds, building location and characteristics etc.). This special issue therefore summarizes the various measurement techniques that are currently available for indoor air measurements and the advantages and disadvantages of each for the indoor environment. For more information, please visit: https://indairpollnet.eu/