Indoor Air Quality. Measurement, sensors, prevention

Indoor air is the air we breathe in enclosed spaces or non-industrial indoor environments. These are typically the places we frequent on a daily basis: our homes, public buildings, office buildings and means of transport. Indoor air quality depends on pollutants from outside and those emitted inside by components of the enclosed space and by human activities. It also depends on indoor air renewal conditions and the supply of outside air through aeration and/or ventilation. A deterioration in indoor air quality due to the accumulation of pollutants is the cause of discomfort and health problems, since we spend between 80% and 90% of our time in enclosed spaces. It quickly translates into nuisances that are not serious, but which disrupt daily life, and which disappear when we leave the enclosed space. These include sensations of discomfort, olfactory nuisances and various symptoms, such as eye, nose and throat irritations, headaches, fatigue, concentration difficulties, respiratory and skin signs, and visual disturbances. But poor indoor air quality also favors carbon monoxide poisoning (in the case of combustion sources), allergic respiratory diseases and the transmission of infectious agents (viruses, bacteria), with a greater impact on vulnerable people (children, pregnant women, the elderly, people suffering from chronic illnesses). Regular exposure to undesirable substances with carcinogenic, mutagenic, reproductive toxic or endocrine-disrupting potential is an aggravating factor in the development of chronic respiratory, cardiovascular or tumor pathologies. The socio-economic cost of exposure in enclosed spaces to six pollutants (benzene, trichloroethylene, radon, carbon monoxide, fine particles and environmental tobacco smoke) has been estimated in France at 19 billion euros annually . In 2022, there are several metrological means available to identify and measure the concentrations of the various biological, physical and chemical pollutants present in our indoor environments. These measurements are carried out by sampling, recording and analysis campaigns in the laboratory or using micro-sensors, at key moments in the life of the building (reception of a new or renovated building, building in operation, investigation following a report). This enables us to better understand the evolution of indoor pollution and to adjust preventive and corrective actions, in order to ensure the comfort, well-being and health of the occupants of these enclosed spaces. Following a review of indoor air sources and pollutants, this article describes the various tools available, both on-site and in the laboratory, and the situations...