Abstract
The air pollution level by suspended particulate matter (SPM) has been lowered in the last few years and the achievement ratio of Environmental Quality Standard for SPM increased rapidly. The achievement ratio means here the number percentage of monitoring stations where the Environmental Quality Standard is achieved. The achievement ratio is still unsatisfactory level than those of other gaseous pollutants.
In this note, the data of SPM measured at the monitoring station in Japan between 1974 and 1983 (Showa 49 and 58) are analysed from several view points and discussed comparing with the Environmental Quality Standard for SPM.
