An IoT-enabled Environmental Ambient Air Pollution Monitoring System was developed using open technologies including open hardware, open software, and open standards. It can detect and measure the concentrations of four major air pollutant gases. The system measures concentrations of air pollutant gases such as NO2, CO, SO2, and O3 using gas sensor modules. The system was developed to comply with IEEE 1451 standard, where the Smart Transducer Interface Module (STIM) was implemented using the Arduino Mega controller. Network Capable Application Processor (NCAP) was implemented using a NodeMCU and ATmega328P controller which is connected to the main board, STIM via the Transducer Independent Interface (TII). The system measures the concentrations of pollutant gases in every 10 seconds and collects all data upto 10 minutes. The measured concentration levels averaged to 10 min intervals and would be sent to the central server with the timestamp and data quality index. For the implementation of a fully open framework, the pollutant data made available free, and anyone can access data and they could be used for a relevant purpose considering the quality index.