Evaluation of Urban Air Quality Monitoring Stations in Ulsan using Geographic Information System

To manage particulate matter (PM2.5) in Ulsan, this study evaluated the current status of the emissions and concentrations of PM2.5 and the number and spatial distribution of urban air quality monitoring stations (AQMSs). The major emission sources of PM2.5 in Ulsan are industrial activities (production process, manufacturing combustion, and ships), and the annual mean concentration of PM 2.5 in Ulsan is not higher than those in other large megacities. However, the toxicity of PM2.5 in Ulsan seems to be high owing to the presence of hazardous air pollutants. Although the AQMSs in Ulsan have been well operated, and the number of stations is sufficient, further evaluation of the roles and spatial distribution of some of these stations is required. This study proposed the priority areas for installing new AQMSs using Geographic Information System (GIS) tools based on the population distribution and PM2.5 pollution levels. The method developed in this study can be used for other cities, as well as for expanding urban areas and new downtown areas in Ulsan to assess the existing monitoring network and suggest the optimum locations of new stations.