What does the phrase, "Like a breath of fresh air," mean to you? This common phrase can have different meanings: calming, relaxing, energizing or clean. In this project we want to find out how clean the air is. We will test the quality of air by measuring the number of air particles from different locations. Students are introduced to the concepts of air pollution and air quality. They watch and conduct several experiments to develop an understanding of the properties of air. Finally, students develop awareness and understanding of the daily air quality using data sheets. Students should be able to identify some of the main causes, effects and sources of air pollution. The project is based on hands-on activities, inquiry based learning and learning via experiments. We use the Arduino platform for mesurements.