On the contrary to a decrease in the average annual PM2.5 concentrations over the last three years, the number of high PM2.5 event has increased in particular. Specifically, in March 2019, the PM2.5 advisory continued for seven days, and on March 5th, the daily average concentration reached 135 µg/㎥. 

The government has implemented emergency reduction measures since 2018 to cope with the high PM2.5 events. However, questions are being raised to the effect of current emergency reduction measures, which respond in a short period of one or two days of high PM2.5 occurred. Consequently, there is a need for new alternatives to cope up the high PM2.5 events. 

Usually, high PM2.5 events occur frequently from late autumn to early spring. Considering the seasonal characteristics of the occurrences of high PM in Korea, it is considered necessary to introduce seasonal PM management system. In this study, definition, aim, period, and measures for the seasonal PM management system were discussed and suggested in an expert forum, which comprised of about 20 experts in related fields.