The overall aim of the Cluster Air Quality was to integrate existing approaches towards health surveillance in relation with indoor and outdoor air quality, which was strongly supported by national and international strategies. This has been achieved through a multidisciplinary dialogue between scientists and authorities at different levels to on one hand identify existing methods, data, information and (bio)surveillance programs in relation with indoor and outdoor air, time activity patterns, health effects (particularly (cardio)respiratory diseases) and human biomonitoring; highlight strengths, weaknesses, gaps and further perspectives in terms of research needs or actions; and test data comparability for potential further integration; on the other hand initiate an active multidisciplinary network and support transfer of knowledge between disciplines