Air pollution is the world’s greatest environmental health risk resulting in millions of premature deaths per year. As well as being an evidently real problem, it is also something that is socially constructed: air pollution is defined by what we decide to measure, and where we take those measurements. These decisions ultimately determine what science is done, and what science remains undone. My research dispels air quality science as a politically neutral endeavour, and instead explores its social implications, and the challenges and opportunities of doing it in a more equitable way.