Monitoring CO₂ concentration to control the infection probability due to airborne transmission in naturally ventilated university classrooms

Assessment of indoor air quality and risk of COVID-19 infection in Spanish secondary school and university classrooms

“…Monitoring indoor CO 2 can also be used to estimate risk of other respiratory diseases, since virus-laden aerosols may easily accumulate as CO 2 does. In this way, it is possible to assess the infection risk of SARS-CoV-2 in each indoor space using CO 2 as a proxy through adaptations of the Wells-Riley model [ 33 , 34 ] among other methods, as in previous examples of studies in university classrooms in Italy [ 35 ].…”

Response to the COVID-19 Pandemic in Classrooms at the University of the Basque Country through a User-Informed Natural Ventilation Demonstrator

“…The COVID-19 pandemic has provoked a renewed interest in methods to predict the risk of infection spread [ 53 , 54 , 55 , 56 , 57 , 58 ], both probabilistic and deterministic, applied to a variety of settings (indoor, outdoor, public transportation [ 59 ], etc. ), as well as tools [ 60 , 61 , 62 ] for direct application.…”

A Retrospective Analysis of Indoor CO2 Measurements Obtained with a Mobile Robot during the COVID-19 Pandemic

“…The concept of indoor air quality is generally associated with the health and comfort of a building's occupants [1]. Carbon dioxide (or CO 2 ) is a chemical compound, produced as a byproduct of the breathing process, that must be analyzed when assessing air quality [2] due to its negative effects on human health, particularly when present in high concentrations [3][4][5][6][7][8]. On average, humans produce around 100 times the original quantity of inhaled CO 2 [3], a high exchange ratio that can contribute to a noticeable rise in CO 2 concentrations, especially in crowded or poorly ventilated indoor spaces.…”

“…In the rise of the COVID-19 pandemic, the World Health Organization (WHO) [17] highlighted that "the risk of getting COVID-19 is higher in crowded and inadequately ventilated spaces where infected people spend long periods of time together in close Sensors 2024, 24, 3102 2 of 16 proximity". The WHO suggested the application of some preventive measures, such as an increase in natural indoor ventilation by opening doors and windows, which were implemented worldwide [4]. However, the analysis of the ventilation regimes performed by Fantozzi et al [4] concluded that, even in naturally ventilated buildings, it is generally not possible to estimate the amount of fresh air entering shared indoor spaces without the use of dedicated ambient sensors measuring the concentration of indoor air pollutant gases such as CO 2 .…”