Ensuring healthy indoor air quality in schools is a public health issue that has not yet been given sufficient attention. Conducting quantitative health impact assessments (QHIA) of air pollution in these environments could be an effective way to convince stakeholders of the importance of taking action. In this context, a feasibility and relevance study was conducted, identifying two possible approaches for implementing initial QHIAs on this topic: A first approach aimed at assessing the impact of improving air quality in elementary school classrooms—by considering formaldehyde concentrations and the presence of mold—on the prevalence of asthma among children aged 6 to 11; A second approach focuses on the benefits of reducing exposure to pollutants from road traffic near schools—using NO₂ as a marker of this pollution—on childhood asthma. The application of the first approach at the national level is presented in this report. This first EQIS estimated that several thousand cases of asthma among children aged 6 to 11 could be prevented each year by reducing exposure to formaldehyde and mold in classrooms. A significant result is notably observed based on a scenario involving improved formaldehyde concentrations linked to better air exchange in classrooms. At this stage, numerous limitations remain. In particular, the estimated benefits should be attributed more to a reduction in exposure to various volatile organic compounds than to formaldehyde alone. Nevertheless, these results confirm the value of continuing efforts to improve classroom air quality and maintaining ventilation practices beyond the health crisis. This study also helps identify the data needed to strengthen the robustness of these initial estimates. Local adaptations of the EQIS model, based on the two approaches identified, will be the subject of a second report to supplement these initial findings.