## 3 Results and Discussion
### Trend Analysis of Atmospheric Aerosols and Gaseous Species
\begin{table}
\begin{tabular}{c c c c c c c c} \hline  & & **S-Value** & **Z-Value** & **\(p\)-Value** & **Trend** & \
\begin{tabular}{c} **Sen’s Slope** \\ **(ug m\({}^{-3}\) y\({}^{-1}\))** \\ \end{tabular} &
\begin{tabular}{c} **Change (Based on 2012)** \\ **(pg m\({}^{-3}\) y\({}^{-1}\))** \\ \end{tabular} \\ \hline \multirow{4}{*}{Seoul} & PM2.5 & \(-5.0\times 10^{5}\) & \(-10.55\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0038\) & \(-1.1\times 10^{-1}\) \\  & SO\({}_{2}\)\({}^{-}\) & \(-4.4\times 10^{5}\) & \(-14.95\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0016\) & \(-9.7\times 10^{-3}\) \\  & NO\({}_{3}\)\({}^{-}\) & \(-2.6\times 10^{5}\) & \(-8.669\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0011\) & \(-5.9\times 10^{-3}\) \\  & NH\({}_{4}\)\({}^{*}\) & \(-2.8\times 10^{5}\) & \(-9.694\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0008\) & \(-3.0\times 10^{-3}\) \\  & EC & \(-4.2\times 10^{5}\) & \(-17.14\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0004\) & \(-6.1\times 10^{-4}\) \\  & OC & \(-3.1\times 10^{3}\) & \(-0.125\) & 0.9 & No trend & – & – \\ \hline \multirow{4}{*}{Baeng-nyeong Island} & PM2.5 & \(-2.9\times 10^{5}\) & \(-8.200\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0027\) & \(-5.8\times 10^{-2}\) \\  & SO\({}_{4}\)\({}^{2-}\) & \(-2.1\times 10^{5}\) & \(-7.605\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0007\) & \(-4.0\times 10^{-3}\) \\  & NO\({}_{3}\)\({}^{-}\) & \(9.9\times 10^{5}\) & \(3.627\) & \(<\)2.2 \(\times 10^{-16}\) & Up (\(\blacktriangle\)) & \(0.0001\) & \(1.9\times 10^{-4}\) \\  & NH\({}_{4}\)\({}^{*}\) & \(-1.4\times 10^{5}\) & \(-5.174\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0002\) & \(-5.1\times 10^{-4}\) \\  & EC & \(-3.2\times 10^{5}\) & \(-11.92\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0001\) & \(-8.2\times 10^{-5}\) \\  & OC & \(-2.4\times 10^{5}\) & \(-8.778\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0005\) & \(-1.7\times 10^{-3}\) \\ \hline \end{tabular}
\end{table} 
Table 2: The results of the Mann–Kendall test and Sen’s slope estimation for ambient aerosols between 2012 and 2019. \begin{table}
\begin{tabular}{c c c c c c c} \hline  & & **S-Value** & **Z-Value** & **\(p\)-Value** & **Trend** & \
\begin{tabular}{c} **Sen’s Slope** \\ **(pgb y\({}^{-1}\))** \\ \end{tabular} &
\begin{tabular}{c} **Change (Based on 2012)** \\ **(pgb y\({}^{-1}\))** \\ \end{tabular} \\ \hline \multirow{4}{*}{Seoul} & SO\({}_{2}\) & \(-4.6\times 10^{5}\) & \(-10.70\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0004\) & \(-2.1\times 10^{-3}\) \\  & NO\({}_{2}\) & \(-4.5\times 10^{5}\) & \(-9.877\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0027\) & \(-7.1\times 10^{-2}\) \\  & CO & \(-8.6\times 10^{4}\) & \(-1.979\) & \(5.253\times 10^{-13}\) & Down (\(\blacktriangledown\)) & \(-0.0118\) & \(-6.4\) \\  & O\({}_{3}\) & \(4.8\times 10^{5}\) & \(11.11\) & \(<\)2.2 \(\times 10^{-16}\) & Up (\(\blacktriangle\)) & \(0.0036\) & \(8.0\times 10^{-2}\) \\ \hline \multirow{4}{*}{Baeng-nyeong Island} & SO\({}_{2}\) & \(-1.2\times 10^{6}\) & \(-29.46\) & \(<\)2.2 \(\times 10^{-16}\) & Down (\(\blacktriangledown\)) & \(-0.0010\) & \(-4.0\times 10^{-3}\) \\  & NO\({}_{2}\) & \(2.8\times 10^{5}\) & \(7.486\) & \(<\)2.2 \(\times 10^{-16}\) & Up (\(\blacktriangle\)) & \(0.0004\) & \(1.2\times 10^{-3}\) \\ \cline{1-1}  & CO & \(3.0\times 10^{5}\) & \(7.108\) & \(<\)2.2 \(\times 10^{-16}\) & Up (\(\blacktriangle\)) & \(0.0249\) & \(7.5\) \\ \cline{1-1}  & O\({}_{3}\) & \(5.4\times 10^{5}\) & \(12.67\) & \(<\)2.2 \(\times 10^{-16}\) & Up (\(\blacktriangle\)) & \(0.0052\) & \(1.2\times 10^{-1}\) \\ \hline \end{tabular}
\end{table} 
Table 3: The results of the Mann–Kendall test and Sen’s slope estimation for ambient gaseous pollutants between 2012 and 2019.