The Internet of Things (IoT) enables connection of unconnected devices, smart solutions for different applications such as transportation, agriculture, health management, industrial automation, smart home and many others.

IoT has opened opportunities for business growth, increased productivity, reduced downtime and it has influenced day to day activities. In this research, the Internet of Things is used to monitor air quality in public transport by the use of environmental sensors and low cost microcontroller to collect data and send it to an open source-Internet of things cloud platform for analysis, storage and visualizations.

The majority of the population in low-and middle-income countries uses mainly public transport in day to day activities. For instance, in Kigali (Rwanda) public buses are the main means of transport since they are affordable compared to other transport means such as private cars, motorbikes, and cabs.

Those buses are often overcrowded with more than 60 passengers each and this may lead to transfer of communicable diseases such tuberculosis and other respiratory diseases and also causes fatigue. These diseases cannot be known and avoided unless there is a monitoring system in place to identify the pollution in air causing these communicable diseases. This research aims at developing an IoT-based air quality monitoring system.

The system incorporates different sensors to measure air quality variables such as carbon dioxide, carbon monoxide, oxides of nitrogen, temperature and humidity and transmits datato the Web server via Wi-Fi for storage, analysis, and data visualization for decision makers.