제주도 고산지역 대기 미세먼지(PM10, PM2.5)의 기상현상별 오염 특성

Abstract

The collection of atmospheric PM10 and PM2.5 particles were made at Gosan site of Jeju Island, which is one of the background sites in korea, during 2016-2018. Their ionic and elemental species were analyzed, in order to examine the chemical composition and emission characteristics in accordance with the various meteorological phenomena. The mass concentrations of PM10 and PM2.5 were 21.0±9.2 and 11.9±6.6 μg/m3 respectively during non-event days. Concentrations of the secondary pollutants such as nss-SO42-, NO3-, and NH4+ were 4.86, 2.79, 2.01 μg/m3 for PM10, and 4.18, 0.81, 1.68 μg/m3 for PM2.5, respectively. The composition ratios of anthropogenic (S, Zn, Pb, Ni), soil (Al, Fe, Ca) and marine (Na, Mg) sources were 44.4%, 21.9%, 23.4% and 61.1%, 19.9%, 7.3% in PM10 and PM2.5, respectively. From the study of particle size distribution, the concentration ratios of PM2.5/PM10 for nss-SO42- and NH4+ were equally 0.9, indicating that those species were existed mainly in PM2.5 particles. On the other hand, NO3-, Na+, Cl- and nss-Ca2+ were relatively rich in PM10 particles. Based on the study of source origins by the principal component analysis, the major components of PM10 particles were originated from marine sources, followed by anthropogenic sources and soil sources. On the other hand, the compositions of PM2.5 particles were influenced mainly by anthropogenic sources, next by marine sources and soil sources. During the Asian dust periods, the concentrations of nss-Ca2+ and NO3 increased highly as 7.2 and 2.4 times in PM10, compared to non-event days. Especially, concentrations of the major crustal species such as Al, Fe, Ca, K, Mn, Ba, and Sr showed a noticeable increase in this periods. For the haze days, concentrations of the secondary air pollutants increased 0.8∼1.6 and 0.8 ∼1.9 times in PM10 and PM2.5, respectively. In addtion, the concentrations of anthropogenic elemental species such as S, Zn, Pb showed a noticeable increase during the haze periods. The neutralization factors by ammonia were 0.75, 0.50, 0.79, and 0.84, respectively, for non-event, Asian dust, haze and mist days in PM10 particles, besides they were 0.92, 0.71, 0.95, and 0.96, respectively, in PM2.5 particles. Meanwhile, those by calcium carbonate were 0.09, 0.49, 0.09, and 0.07 in PM10 particles, and 0.02, 0.13, 0.03, and 0.01 in PM2.5 particles, respectively. The clustered backward trajectory analysis showed that the concentrations of secondary pollutants such as NO3-, nss-SO42-, and NH4+ increased remarkably, when the airflow moved from China continent. On the other hands, they decreased when the airflow moved from the Northern Pacific Ocean. Likewise, in back trajectory analysis, the concentrations of secondary pollutants in both PM10 and PM2.5 particles were higher when the airflow moved from China continent to Jeju Island.