This document is a practical guide intended for professionals working in local governments, state agencies, public organizations, accredited air quality monitoring associations (AASQA), regional health observatories (ORS), consulting firms, and others, wishing to conduct EQIS studies on outdoor air pollution in accordance with the general framework recommended by the WHO and the tools used within the framework of Santé publique France’s Psas (Air and Health Monitoring Program). This guide is available in three versions depending on the objectives set and the available data on exposure to air pollution.