## 3 Results
### OC Characteristics of PM\({}_{2.5}\) in Orchard Areas  
Table 2 shows the results of PM\({}_{2.5}\) and gaseous compounds in real-time at the orchard area observed during the study period. The rePM\({}_{2.5}\) presented in the table is the result of summing the concentrations of OC, EC, water-soluble ions, and heavy metals among the analysis compounds. rePM\({}_{2.5}\), OC, water-soluble ion, heavy metal, and EC were 47.91, 43.20, 5.02, and 3.87%, respectively. In this study, H, N, S, O, and other water-soluble ions other than the three components, which constitute organic substances other than carbon, were not analyzed. However, since the contents of H, N, S, and O, excluding the carbon component, are generally calculated using the OM/OC ratio based on the molecular weight of each component constituting the OC, the OC presented in this study can represent the amount of organic aerosols included in PM\({}_{2.5}\)[34; 35; 36; 37]. Additionally, according to previous studies, the SO\({}_{4}\)\({}^{2-}\), NO\({}_{3}\)\({}^{-}\) and NH\({}_{4}\)\({}^{+}\) (SNA) analyzed in this study takes the largest portion of the PM\({}_{2.5}\) ionic components, and these components are known to be important factors in SOA formation [38]. Therefore, based on the concentration of OC and the three water-soluble ions presented in this study, it is judged that there will be no major issue in interpreting the cause of PM\({}_{2.5}\) in agricultural areas. In conclusion, it can be confirmed that OC and ion components have a great impact on PM\({}_{2.5}\) in agricultural areas. OC can be briefly divided into water-insoluble OC (WIOC) and water-soluble organic carbon (WSOC). WIOC mainly originates through the combustion of fossil fuels, and is known to be emitted from primary origins [39; 40]. On the other hand, WSOC can be emitted directly as primary particles from biomass combustion (BB) sources, or can originate by SOA formation [24; 41; 42]. Therefore, in this study, the proportion of WSOC among OCs was confirmed, and the result showed that WSOC took 95.09% of OCs. In other words, it can be confirmed that the PM\({}_{2.5}\) in the study area originated through the combustion of biomass or the reaction of SOA formation, rather than originating from the combustion of fossil fuels. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Compounds (Unit: mg/L)** & **Pesticide** & **Disinfectant** & **Herbicide** & **Evaporation Agent** \\ \hline Acrylonitrile & 0.45 & 0.58 & 0.05 & 260.36 \\
1,1-Dichloroethane & 0.03 & - & 0.01 & 0.09 \\ Chloroform & 1.56 & 1.44 & - & - \\
1,2-Dichloroethane & \textless{}0.00 & \textless{}0.00 & \textless{}0.00 & \textless{}0.00 \\
1,1,1-Trichloroethane & - & \textless{}0.00 & - & 0.01 \\ Benzene & - & 24.13 & 20.86 & 18.51 \\ Carbon tetrachloride & - & - & 0.16 & 0.14 \\ Trichooreethylene & - & - & 0.04 & - \\ Toluene & 8.01 & 6.22 & 1.88 & 1.31 \\ Tetrachloroethylene & - & - & - & - \\ Chlorobenzene & 0.38 & 2.01 & 0.42 & 0.72 \\ Ethlybenzene & 0.19 & 20.15 & 1.59 & 1.42 \\ m\&p-Xylene & 2.79 & 15.76 & 2.00 & 1.71 \\ Styrene & - & 8.69 & 2.51 & - \\ o-Xylene & 0.19 & 5.57 & 0.62 & 0.82 \\ Bromobenzene & - & - & - & 0.2 \\ Isopropylbenzene & - & - & - & - \\
2-Chlorotoluene & 0.06 & 0.22 & 0.03 & 1.10 \\ n-Propylbenzene \& 4-Chlorotoluene & - & 0.89 & 0.27 & - \\
1,3,5-Trimethylbenzene & - & 0.24 & 0.19 & - \\ p-isopropylbenzene & 0.13 & - & - & 0.94 \\
1,2,4-Trimethylbenzene & - & - & - & - \\
1,2-DiChlorobenzene & - & - & - & 2.24 \\
1,3-DiChlorobenzene & \textless{}0.00 & \textless{}0.00 & \textless{}0.00 & \textless{}0.00 \\ sec-Butylbenzene & - & 0.06 & 0.03 & - \\ tert-Butylbenzene & - & - & - & - \\
1,4-DiChlorobenzene & 0.12 & \textless{}0.00 & - & 0.01 \\ n-Butylbenzene & - & 0.46 & 2.29 & 1.23 \\ Naphthalene & - & - & 0.69 & 418.64 \\
1,2,4-Trichobenzene & - & - & - & 0.70 \\ Hexachloro-1,3-butadiene & - & - & - & 0.48 \\ Total VOCs (sum) & 13.92 & 86.43 & 33.63 & 710.71 \\ \hline \hline \end{tabular}
\end{table}