A Smart Environmental Air Pollution Monitoring System (SEAPMS) based on internet of things (IoT) has been built for monitoring the concentrations of major air pollutant gases, as well as a fire extinguishing system for fire detection and prevention. Using a network of sensors, the SEAPMS detects gas concentrations such as carbon monoxide CO, carbon dioxide CO 2 , methane CH 4 , dust, smoke, temperature, and humidity. The sensors will collect data on numerous environmental characteristics and send it to particle photons, which will compare it to a predetermined threshold for each sensor then sends it to a special IoT platform known as UBIDOTS. UBIDOTS sends data to the cloud then they will be realized and virtualized to be displayed. The fire extinguishing system will activate when the smoke concentration exceeds its threshold limit value.