Evidence for a causal relationship between air pollution and disease is present in ninety percent of the urban population, having an impact mainly on predisposed individuals. Respiratory health is a condition highly affected by outdoor and indoor air pollution. In more detail, exposure to a variety of environmental air pollutants may exacerbate a group of respiratory diseases comprising by chronic obstructive pulmonary disease, asthma, respiratory infection, and lung cancer. In this paper, we propose a comprehensive methodology to implement an air quality monitoring system towards the prevention of the effects of air pollution on respiratory health. Our approach combines distributed sensors that collect air quality information at regular intervals. Outdoor air quality monitoring stations, indoor air quality devices, and wearables, form the sensor network in the proposed system. The air quality monitoring system includes also an artificial intelligent monitoring module and a clinical decision support module, for personalized guidance, which has been developed and successfully deployed in asthma disease.