This paper presents a web information system and a wireless sensor network for indoor or outdoor air quality monitoring with application in asthma trigger factors assessment. As the main target is mentioned the development of a flexible system characterized by a low-cost sensing nodes that assures robust and continuous monitoring of air conditions in order to prevent the asthma attacks. At the same time it permits to establish correlations between the air quality parameters and the appearance of respiratory diseases such as asthma. The architecture of the system is based on a wireless sensor network that includes a set of sensing nodes with ability to measure environment parameters like temperature, relative humidity, carbon monoxide among others and to send processed information to a smart coordinator. Two different architectures of smart coordinator based on a Raspberry Pi embedded computer and wireless network coordinator were implemented, with and without an Ethernet border router from Jennic. Referring the software, a client application that uploads the measured data to a remote air quality server through Internet was designed and implemented. The primary processing is done by the smart coordinator that transmits the processed values of air quality parameters including alarms to a web based information system. Referring the web based information system it assures the human machine interface, the users being capable to receive alerts, and to visualize the data associated with wireless sensor network, and to monitor network status.