Characteristics of air pollution of agricultural region in high PM episodes using air quality measurement data of megacity and agricultural sites from 2023 to 2024

There are about 800 air pollution measurement networks (urban, roadside, rural and so on) in Korea, however air pollution in agricultural area are not measured. Thus it is necessary to identify air pollution in agricultural area which possess a relatively larger area than urban area. In this study, we established eight air pollution monitoring stations in agricultural area, and we conducted to comparatively analyze the air quality in agricultural and urban areas, during the periods for 1) the entire measurement data, 2) high PM episodes, and 3) non-high PM episodes. Considering the spatial distribution by region of Korea, air pollution monitoring stations were established in in agricultural area (Yeoju, Nonsan, Naju, Gimhae, Hongcheon, Danyang, Muan, and Sangju). PM-10 and PM-2.5 (ß-Ray attenuation method), SO₂ (Ultraviolet fluorescent method), NOx and NH₃ (Chemiluminescence method) were measured in real-time. Meteorological data such as temperature, humidity, wind direction, and wind speed were also measured. One-year measurement data from October 2023 to September 2024 were used, and high-PM episodes was defined as the period when the PM-2.5 concentration exceeds 24-hour air quality standard (35 μg/m³) of Korea and persists for 24 hours or more. The air quality data of urban area (near large cities: Suwon, Daejeon, Gwangju, Busan, Chuncheon, Cheongju, and Daegu) during the same period were used to compare to the air quality of agricultural area. During the entire period, the average concentrations in urban and agricultural areas were found to be similar for both particulate and gaseous compounds. During non- high PM episodes, agricultural and urban areas also showed similar levels. During high PM episodes (a total of 17 days), while the concentration of air pollutants in urban areas was obviously higher than those in agricultural area, but higher concentrations of particulate matter in agricultural areas were observed during certain periods (PM-10 in the morning and PM-2.5 in the afternoon). Gaseous concentrations in agricultural areas were found to be lower than those in urban area during the high PM episodes. In the future, it is necessary to analyze the characteristics of the variation of air pollution according to concentration changes by period (diurnal variation), solar intensity, and meteorological factors to clarify the differences in characteristics of air quality between agricultural and urban areas.

Acknowledgments

"This research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute(KEITI) funded by the Ministry of Environment(MOE)"