Identification of Pollution Characteristics of PM2.5 Using a Geographic Information System and Statistical Tools: A Case Study of the Southeastern and Southern Regions of South Korea

Abstract

In recent years, fine particles (PM2.5) have become a major environmental issue in South Korea, making it necessary to investigate the regional pollution characteristics of PM2.5 to establish effective PM2.5 management policies. This study employed a geographic information system (GIS) and statistical methods, such as space-time cube analysis and principal component analysis (PCA), to identify the characteristics of high PM2.5 events and the factors influencing PM2.5 levels in the southeastern and southern regions of South Korea. The periods in which PM2.5 levels exceeded the very unhealthy state, as defined by the air quality standard of South Korea, were designated as Pollution Episodes 1 and 2 in the southeastern and southern regions, respectively. The findings revealed that both Pollution Episode 1 and Pollution Episode 2 were influenced by long-range atmospheric transport (LRAT) from Asian continental outflow as well as atmospheric stagnation within South Korea. In addition, local industrial activities and the secondary formation of SO4 2- and NO3 - were identified as major sources of PM2.5 in both episodes. However, the impact of industrial emissions was more pronounced in Pollution Episode 1, whereas the secondary formation of NH4 + and the influence of natural sources were predominant only in Pollution Episode 2. Therefore, reducing both industrial emissions in the southeastern region and the formation of secondary inorganic aerosols in the southern region would be practical approaches to improve air quality. The results of this study, which utilized GIS and statistical techniques to analyze regional pollution characteristics, can be further employed to visually and quantitatively identify PM2.5 pollution sources.