Coop'Air : a participatory research initiative to monitor classrooms indoor air quality in classrooms through combined measurements of active devices and biosensors (France, Ivory Coast and Brazil).

Ensuring good air quality in children's environments is recognized as a critical public health issue, which raises the question of monitoring indoor air quality (IAQ) in classrooms as poor air quality affects children's health and academic performance. To better understand the dynamics that affect classroom air quality in urban environments, we examined some physical characteristics of the classroom, including ventilation and occupancy in contrasting contexts. A combined set of low-cost optical devices, CO2, humidity and temperature sensors as well as passive biosensors (Tillandsia usneoides, tree barks) was implemented in 5 classrooms in the urban context of the medium-sized Toulouse city (France), 3 classrooms in the West African capital city of Abidjan (Ivory Coast) and 2 classrooms in the megacity of Sao Paulo (Brazil). Concentrations of particulate matter (PM), CO2 and comfort data (humidity and temperature) were monitored every 2 minutes over more than 6 months in 2024.  Processing the data according to whether the class is occupied or not allows to assess the impact of the presence of children and their activities on IAQ. Besides, the elemental composition of PM deposited on biocaptors exposed in the classroom, analyzed by ICP-MS for Toulouse and Abidjan, allows the identification of PM sources within classrooms. The results are part of the Coop’Air participatory research experiment designed by an interdisciplinary team to co-construct with the children appropriate measures to improve indoor air quality in their classroom.