Abstract
The characteristics of $PM_{10}$, $PM_{2.5}$ and Ratio($PM_{2.5}/PM_{10}$) of 11 urban air monitoring stations in Gyeongnam were analyzed for the last 3 years('15~'17). The average of the all stations was $PM_{10}\;45{\mu}g/m^3$, $PM_{2.5}\;24{\mu}g/m^3$ and Ratio 0.54, and annual reduction rates were $PM_{10}-2.9%$, $PM_{2.5}-2.7%$ and Ratio -1.2%, respectively. The seasonal characteristics of $PM_{10}$ were spring $54{\mu}g/m^3$ > winter $48{\mu}g/m^3$ > summer/autumn $40{\mu}g/m^3$, $PM_{2.5}$ were spring/winter $26{\mu}g/m^3$ > summer 23 > autumn $22{\mu}g/m^3$ and Ratio were summer 0.56 > winter 0.55 > autumn 0.54 > spring 0.51, respectively. The hourly characteristics of $PM_{10}$ were $11{\mu}g/m^3$ higher than 09:00~12:00 at 03:00~06:00, $PM_{2.5}$ were $6{\mu}g/m^3$ 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 $PM_{10}$ was YJ site $53{\mu}g/m^3$ and $PM_{2.5}$ was HW site $28{\mu}g/m^3$. And Ratio at HD site showed the largest reduction from '15 0.62 to '17 0.52.