The NSW DECC (Department of Environment and Climate Change, formerly EPA) has an air quality monitoring program that collects accurate real-time measurements of ambient level pollutants at 24 monitoring sites within the air quality monitoring network, located around the greater metropolitan area of Sydney, the Illawarra, the Lower Hunter and selected rural sites around NSW.
If you want to find out more about the DECC air quality measurements, follow the link provided: Department of Environment and Climate Change.