A Saturday in Nanshan
http://www.255.ch/stuff/busta/busta.html
Kudos to Gregor for re-finding this piece of art!
0 - 50 Good Air quality is considered satisfactory, and air pollution poses little or no risk. 51 - 100 Moderate Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution. 101 - 150 Unhealthy for Sensitive Groups Members of sensitive groups may experience health effects. The general public is not likely to be affected. 151 - 200 Unhealthy Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects. 201 - 300 Very Unhealthy Health alert: everyone may experience more serious health effects. 301 - 500 Hazardous Health emergency: the entire population is more likely to experience serious health effects.
