Today, cities across the world are fight- ing against the proliferation and concentration of particulate matter – aka air pollution – within their boundaries. These particles are too small to be seen with the human eye, and while electronic sensors can give us precise measurements to tell us just how much pollution there is in our air, these remain ab- stract concepts – it’s difficult for the average citi- zen to understand just how dirty (or clean) our air is based on a number. In his project DUST, the artist Michael Saup uses virtual reality technology to render the normally invisible realm of urban air pollution (as well as its effect on people) both visible and accessible. Saup presents the city of Berlin with 3D “pixel clouds” that are constantly changing based on real-time measurements from a fleet of citizen-built sensors that feed their data into the open data network luftdaten.info.