초록 열기/닫기 버튼
Public's anxiety on ambient PM2.5 level is increasing. To check whether the anxiety is related the PM2.5 concentration, the long-trem trends of (1) the PM2.5 concentration, high PM2.5 concentration frequency fraction, frequency of the high concentration occurrence duration time (three indicators), (2) PM2.5/PM10, (3) PM2.5/PM10 when PM2.5≥50 μg/m3 and <10 μg/m3 in Seoul between 2003 and 2018 are studied. Generally, all three indicators have decreased. For example, the annual mean PM2.5 concentration decreased from 37 μg/m3 in 2003 to 23 μg/m3 in 2018 in Seoul. However, the frequency fraction of PM2.5 exceeding 75 μg/m3 has increased since 2016. The frequency of the occurrence duration time of PM2.5≥50 μg/m3 has increased also since 2015. The PM2.5/PM10 increased while the concetnrations of PMs, because the PM10 concentration decreased more than PM2.5 concentration in Seoul between 2003 and 2018. The PM2.5/PM10 when PM2.5≥50 μg/m3 and <10 μg/m3 are also increased in Seoul between 2003 and 2018 and has incrased rapidly since 2014 when PM2.5≥50 μg/m3.
