The characteristics of PM10, PM2.5 and Ratio(PM2.5/PM10) of 11 urban air monitoring stations in Gyeongnam were analyzed for the last 3 years(`15~`17). The average of the all stations was PM10 45 μg/㎥, PM2.5 24 μg/㎥ and Ratio 0.54, and annual reduction rates were PM10 -2.9%, PM2.5 –2.7% and Ratio –1.2%, respectively. The seasonal characteristics of PM10 were spring 54 μg/㎥ > winter 48 μg/㎥ > summer/autumn 40 μg/㎥, PM2.5 were spring/winter 26 μg/㎥ > summer 23 > autumn 22 μg/㎥ and Ratio were summer 0.56 > winter 0.55 > autumn 0.54 > spring 0.51, respectively. The hourly characteristics of PM10 were 11 μg/㎥ higher than 09:00~12:00 at 03:00~06:00, PM2.5 were 6 μg/㎥ higher than 09:00~12:00 at 17:00~18:00 and Ratio were 0.07 higher than 04:00~06:00 at 19:00. By site, the highest concentration of PM10 was YJ site 53 μg/㎥ and PM2.5 was HW site 28 μg/㎥. And Ratio at HD site showed the largest reduction from `15 0.62 to `17 0.52.

Abstract
 1. Introduction
 2. Methodology
  2.1. Air monitoring network in Gyeongnam
  2.2. Process PM10 and PM2.5 collection data
  2.3. Status of Asian dust and high concentrationdust alarm
 3. Results and discussion
  3.1. Daily average change over the last three years
  3.2. Monthly and hourly change characteristics
  3.3. Characteristics of 11 monitoring sites
 4. CONCLUSIONS
 REFERENCES

• Jeong-Ho Park(Department of Environmental Engineering, Gyeongnam National University of Science and Technology, Jinju 52725, Korea) Corresponding author
• Jeong-Min Suh(Department of Bioenvironmental Energy, Pusan National University)